ÎHTRATED AMD BENZYLATED .ALIXDÎHC ACIDS

AMD IKEIR USE IN SYNTHESES

DISSERTATION

Presented in Partial Eulfillment of the Requirements

for the Degree Doctor of Philosophy in the

Graduate School of The Ohio State

Universi ty

B y

ADEX ROSENTHAL, D.Sc., B.Ed. , M.Sc,

The Ohio State University

19 52

Approved hy:

Adviser 1

TABLE OF CONTENTS

PART I Page I. OBJECTIVE...... 1

II. HISTORICAL...... 2

A . General...... 2

B. AldonicAcids and Their Lactones...... 3

C. Preparation of D-Gluconic and D- Galactonic Acids...... 7

1, Commercial Preparation of D-Glu­ conic Acid by Fermentation Methods...... 7

2, Preparation of D-Galactonic Acid... 10

3, Chemical and Electrolytic Methods of Preparing Aldonic Acids...... 11

D . Preparation of Aldonamides...... 14-

E. Preparation of Sugar Nitrates 15

1. General...... 15

2. Nitration of Carbohydrates with Nitrogen Pentoxide...... 18

(a) Nitrogen Pentoxide...... ,,..,, IS (b) Use of Nitrogen Pentoxide as a Nitrating Agent...... 19

F . Fully 0—Esterifled Aldonic Acids...... 21

G. Reaction of Diazomethane with Sugar Acids...... 24.

1. Diazomethane...... 24-

2. Action of Diazomethane on Aldonic Acids...... 27

S81010 11

TABLE OF CONTENTS (cont.) Page

H, Stabilizers of Nitrated Carbohydrates.. 27

I, Stability Tests of Nitrated Carbohydrates...... 30

J. Double-Base Powders and Films...... 32

III. EXPERIMENTAL...... 34

A. Synthesis of Methyl D-Galactonate Pentanitrate ...... 34

1. Preparation of D-Galactonamide 34

2. Attempted Nitration of D-Galac- tonamide with Nitric-Sulfuric Acids...... 35

3. Attempted Nitration of D-Galac— tonamide with Nitric-Acetic Acids,. 35

4. Preparation of Nitrogen Pentoxide,. 36

5. Synthesis of D—Galactonamide 0-Pentanitrate...... 3B

6. Synthesis of D-Galactonic Acid.,.., Pentanitrate...... 40

7. Preparation of Diazomethane...... 42

8. Synthesis of Methyl D-Galacton- ate Pentanitrate ..... 43

B. Synthesis of Methyl D-Gluconate Pentanitrate ...... 45

1. Preparation of D-Gluconamide ...... 45

2. Synthesis of D—Gluconamide 0-Pentanitrate...... 46

3. Synthesis of D-Gluconic Acid Pentanitrate...... 47

4. Synthesis of Methyl D-Gluconate Pentanitrate ...... 48 Ill TABLE OF CONTENTS (cont.)

Page

0. Stability and Sensitivity of Nitrates,, 49

1, Determination of Stability of Nitrates ...... 49

2, Determination of Sensitivity of Nitrates...... 49

D . Compatibility of Nitrated Aldonic Acid Derivatives and Cellulose Nitrate 51

1, Preparation of Films of Cellulose Nitrate and Derivatives of Aldonic Acid Nitrates...... 51

2, Preparation of Films of Cellulose Nitrate, Aldonic Acid Nitrate Derivatives and Diphenylamine...... 52

3, Determination of Stability of Double-Base Films,...... 52

IV. DISCUSSION OF RESULTS...... 55

A. General...... 55

B. Preparation of Starting Materials...... 55

1. Preparation of D-Galactonamide 55

2. Preparation of D-Gluconamide...... 56

3. Preparation of Nitrogen Pentoxide.. 56

C, Preparation of Aldonamide 0—Pentanitrates

1. Attempted Nitration of Aldonamides with Nitric Sulfuric Acids...... 57

2. Attempted Nitration of D—Galac— tonamide with Nitric-Acetic Acids., 57

3. Preparation of Aldonamide 0-Penta- nitrates Using Nitrogen Pentoxide,, 58

D, Preparation of Aldonic Acid Pentanitrates...... 62 iv

TABLE OF CONTENTS (cont,)

Page

E, Preparation of Methyl Aldonate Pentanitrates...... 64

1. Diazomethane...... 64

2, Preparation of Methyl D-Galactonate Pentanitrate and Methyl D-Gluconate Pentanitrate...... 65

F, Stability and Sensitivity of Nitrated Aldonic Acids and Their Derivatives... 66

G, Compatibility and Stability of Films of Aldonic Acid Nitrate Derivatives and Cellulose Nitrate...... 69

H, Action of Diphenylamine on Double- Base Films...... 70

V. ACKNOWLEDGMENTS...... 71

VI. SUMMARY...... 72 V

TABLE OF CONTENTS (cont.)

TABLES

Page

Table I» Stability and Sensitivity of Nitrates,,,...... 50

Table II. Films of Aldonic Acid Penta­ nitrate Derivatives and Cellulose Nitrate, 53

Table III, Films of Aldonic Acid Penta­ nitrate Derivatives and Cellulose Nitrate with Di— phenylamine ...... 54 vi

TABLE OF CONTEKTS

PART II Page

I. OBJECTIVE...... 74

II. HISTORICAL ...... 76

A, Polyesters...... 76

III. EXPERIMENTAL...... 79

A. Preparation of D-Galactony1 Chloride Pentanitrate...... 79

1, Using Phosphorus Pentachloride,.., 79

2, Using Thionyl Chloride...... SO

B. Attempted Preparation of Ethylene Glycol Di-D-Galactonate Penta­ nitrate ...... SO

1. Using Pyridine as Catalyst...... SO

2. Using Excess Pyridine and Ether as a Diluent. SI

3. Using Excess Pyridine...... S2

4. Using n-Tributylamine as Catalyst...... S2

5. Using Kalcite HCR (Resin) as Catalyst...... S2

6. Using No Catalyst and Dioxane as Solvent,...... S3

7. Using No Basic Catalyst and Glacial Acetic Acidas Solvent,.., S3

8. Using Silver Carbonate...... 83

C. Attempted Direct Estérification of D-Galactonic Acid Pentanitrate with Methanol...... 84 vil TABLE OF CONTENTS (cont.) Page

1. Using Dowex 50 as Catalyst...... B4-

2, Using Sulfonic Acid as Catalyst...... 85

IV. DISCUSSION...... 86

A, Preparation of D-Galactony1 Chloride Pentanitrate...... 86

B, Attempted Preparation of Ethylene Glycol Di-D-Galactonate Penta­ nitrate ...... 86

C, Attempted Direct Estérification of D-Galactonic Acid Pentanitrate with Methanol...... 88

1. Using Dowex 50 (Resin) as Catalyst 88

2. Using 2,-Toluene Sulfonic Acid as Catalyst...... 88

V. SUMMARY...... 89 viii TABLE OF CONTEHTS

PART III Page

I. OBJECTIVE...... 90

II. HISTORICAL...... 94

A. Benzyl Ethers of Carbohydrates 94

B. Sugar Mercaptals...... 97

III, EXPERIMENTAL...... 100

A. Attempted Complete Benzylation of D—GluconannSe. 100

1. First Benzylation of 0-Potassium Alkoxide of D-Gluconamide with Benzyl Chloride in the Presence of Liquid Ammonia ...... 100

2. First Rebenzylation of Partially Benzylated D-Gluconamide with Benzyl Chloride in the Presence of Liquid Ammonia...... 101

3. Second Rebenzylation of Partially Benzylated D-Gluconamide with Benzyl Chloride 101 B. Attempted Benzylation of D-Gluconamide with Sodium Naphthalene Reagent and Benzyl B r o m i d e . 103 1. Preparation of Sodium Naphtha­ lene Reagent. 103

2. Attempted Benzylation of D- Gluconamide with Sodium Naphtha­ lene Reagent...... 104

C. Preparation of D—Gluconic Acid Pentaacetate ...... 103

D . Attempted Preparation of Penta-0- benzyl-D-Gluconic Acid...... 105 ix

TABLE OF CONTENTS (cont.) Page

1, Using Benzyl Bromide as Be-nzylating Agent,...,,,,,,,,,..,, 105

2, Chromatography of Benzylated D-Gluconic Acid,,...... 107

3, Using Benzyl Chloride as Benzy- lating Agent.,.,...... 109

E. Preparation of Pentabenzyl-D—Glucose Diethyl Mercaptal...... 110

1. Preparation of D-Glucose Diethyl Mercaptal...... 110

2. Attempted Benzylation of Alkoxide of D—Glucose Diethyl Mercaptal,.., 110

3. Synthesis of Pentabenzyl-D-Glucose Diethyl Mercaptal...... Ill

(a) First Benzylation of D- Glucose Diethyl Mercaptal,.., Ill (b) Second Benzylation...... 113 (c) Third Benzylation...... 114 (d) Chromatography of 0—Penta— benzyl-D-Glucose Diethyl Mercaptal...... , 115

F . Preparation of Pentabenzyl-aldehvdo-D- Glucose ..... 116

G. Synthesis of Pentabenzyl-D-Gluconic Acid...... 117

17. DISCUSSION...,...... 120

A, General...... 120

B, Attempted Complete Benzylation of D- Gluconamide ...... 121

1, Attempted Benzylation of (O- Potassium Alkoxide)of D-Glucon­ amide with Benzyl Chloride...... 121 X

TABLE OF CONTENTS (cont.) Page

2, Attempted Benzylation of D-Glncon- amide with Sodium Naphthalene Reagent and Benzyl Bromide...... 122

C. Attempted Preparation of Pentabenzyl-D- Gluconic Acid...... 123

1, Using Benzyl Bromide...... 123

2, Using Benzyl Chloride...... 125

D. Synthesis of Pentabenzyl-D-Glucose Diethyl Mercaptal...... 125

1. Preparation of D-Glucose Diethyl Mercaptal .»... 125

2. Attempted Benzylation of (O- Potassium Alkoxide)of D-Glucose Diethyl Mercaptal...... 126

3. Synthesis of Pentabenzyl-D- Glucose Diethyl Mercaptal,, 126

E. Preparation of Pentabenzyl-aldehydo-D- Glucose...... 129

F . Synthesis of Pentabenzyl-^-Glucorfic Acid...... 129

V. SUMMARY...... 131

VI. CHRONOLOGICAL BIBLIOGRAPHY...... 133

VII. ACKNOWLEDGMENTS...... lAl

VIII. AUTOBIOGRAPHY,...... 14-2 - 1-

NITRATED AND BENZYLATED ALDONIC ACIDS

AND THEIR USE IN SYNTHESES

PART I

NITRATED ALDONIC ACIDS

I. OBJECTIVE

The only monosaccharide sugar nitrates formerly quite extensively investigated for their explosive properties have been those derived by nitrating aldoses or methyl aldosides and these have been generally found to be un­ stable. With the successful development of mold fermenta­ tion of molasses, there now exists a potentially large commercial source of the lactones of ^-gluconic acid. As a consequence, D—glueono-5—lactone was used in our investi­ gation as a starting material with the objective of preparing the amide and the methyl ester dei-ivatives of

D-gluconic acid pentanitrate. A concomitant objective of this research was the testing of the stability of these nitrated compounds and the determination of their com­ patibility with cellulose nitrate.

A further purpose of this work was to carry out the synthesis of methyl D—galactonate pentanitrate and its intermediates and also to test the stability of these compounds and their compatibility with cellulose nitrate. — 2—

II., HISTORICAL

A. General

The aldonic acids are monobasic sugar acids which

undergo intraestérification or lactonisation with ease,

and this is the form in which they are generally obtained*

Although some of the free aldonic acids have been prepared by crystallization from solvents in which lactonisation

is hindered, they have found little use in synthetic work

for the reason previously mentioned* In contradistinction

to this fact, the lactones of the sugar acids are often

used as starting materials in the syntheses of new com­

pounds*

The ready conversion of the lactone into an aldonamide

provides an easy method of blocking intraestarification

and permits the utilization of all hydroxyls on the sugar

molecule for estérification with organic or inorganic

acids* Subsequently, the fully 0-esterified aldonamide may be deaminated to produce the fully 0-esterified aldonic

acid. The latter, when reacted with diazomethane, produces

the methyl ester derivative of the aldonic acid* These

transformations, utilized in the research reported herein

and discussed more fully in the following sections, may

be illustrated by the following reaction sequence* - 3-

CO

COHHg GONE, t HCO (GHOH), (CHOGOR),

CHgOH CHgOH GHgOGOR

Aldono— Aldonamide Esterifled lactone aldonamide

GOGH CO2CH3 I (GHOGOR), (CHOGOR), » ^ CHgOGOR CHgOGOR

Esterifled Methyl ester derivative aldonic acid of esterifled aldonic acid

B, Aldonic Acids and Their Lactones

In aqueous solution the aldonic acids form and S*

lactones spontaneously and reverslbly (l, 2), This Is

(1) P, A, Levene and H, S, Simms, J* Biol, Chern,, 6i, 31 (1 9 2). 5 (2) ¥, Charlton and W. N. Haworth, J, Ghem. Soc., 89 (1 9 2); 6 M. N. Haworth and 7. S. Nicholson, Ibid., 1899 (1926).

Illustrated In the case of ^-gluconic acid by the follow­

ing formulas. "4- co— GOGH GO—I t t Î HCOH HGGH HGGH t t » HOCH HGGH HGGH t I : H20 t HCOH HGGH HCO-J t t I HOG—I HGGH HCOH t t t CHgOH GH^GH CHgGH

D-glucono-5- fi-gluconic D-gluc ono-y- lactone acid lactone

Levene and Simms (l) showed clearly that lactonisation of an aldonic acid took place in two steps. In the first stage there was a very rapid formation of the nnstable

5-lactone, and in the second, a slow formation of the stable y-lactone and the disappearance of the former. They also showed that the presence of free hydrochloric acid increased the rate of lactonisation of the free aldonic acid. The relative amounts of the S- and y-lactones in the equilib­ rium solution are subject to wide variation and are de­ pendent on pH, temperature, and concentration of the solution; the main components of the equilibrium mixture are the free acid and the y-lactone. The equilibrium is attained very slowly, weeks being required for aqueous solutions at room temperature*

The problem of isolating the free aldonic acids as well as the lactones in pure form has been studied for more than one—half century. As early as 1890, Fischer — 5“ (3) obtained the Y-lactone of D-gluconic acid in practically

(3) E. Fischer, Ber., 21, 262$ (1890)* pure condition, Hef and Hedenburg (4) found that the best

(4) J. U. Nef, Ann., 4£1, 322 (1914)J 0. F. Heden­ burg, J. Am.. Ghem. Soc. , 12, 345 (191$). condition for obtaining the Y-lactone was by heating an aqueous solution of D-gluconic acid. The latter authors

(4) also prepared D—glucono- S-lactone from calcium D— gluconate and oxalic acid in water. An interesting dis­ covery was recently made by Wolfrom and co-workers ($)

($) M. L. Wolfrom, B. W. Lew and R. M. Goepp, Jr., J. Am, Ghem. Soc,, 1449 (1946) * who showed that it was possible to separate D-gluconic acid from its lactones by means of the chromatographic method. They found that it was possible to follow the rate of delactonization of 1—glucono- Y-lactone and D- glucono-§ —lactone by this method, Schnelle and Tollens

(6) were the first to obtain crystalline D-galactono-

(6) W, Schnelle and B. Tollens, Ann,, 2 7 1 . 81 (1892)

T-lactone hydrate but they did not assign a structural formula to it,

A solution supersaturated with respect to both free acid and lactone can often be seeded with appropriate — 6— crystals and the desired product, that is, lactone or acid, thus obtained. Normally, the free aldonic acid is obtained by concentration of the aqueous solution at a low temperature is vacuo. The free acid has also been prepared by crystallization from solvents in which lactone formation is hindered (7), The § -lactone is obtained by

(7) H, S. Isbell and H, L. Frush, Bur. Standards J. Research, 6, 1145 (1931); 11, 649 (1933); K. Rehorst, Ber., 61, 163 (1928); 2279 (1930). dehydrating the acid solution at a low temperature in the absence of mineral acid and with proper seeding, whereas the y -lactone is prepared by dehydrating the acid at a higher temperature in the presence of mineral acid.

Distillation with butanol or dioxane or by heating in vacuo serves to remove water and thus aids formation of the lactone.

On prolonged heating with bases, aldonic acids are slowly converted into their epimers. Fischer (8) found

(8) E. Fischer, Ber., 2^, 799 (1890). that pyridine was effective in bringing about such an epimerization. Subsequently, the mixture of acids could be separated and thus a method of synthesis of aldonic acids was provided. £-Gluconic acid, heated with barium hydroxide at 100® for 115 hours, is converted to fi- mannonic acid in a yield of 20^. As the reverse reaction - 7- under the same conditions provides only 12^ conversion

to D-gluconic acid, the attainment of equilibrium is

very slow (9). The lactone is less reactive than the

(9) H. T, Bonnett and F. W* Upson, J, Am. Chem. Soc., ii, 1245 (1933).

free acid toward alkali. Sodium carbonate reacts with

the 5 -lactone, and an excess of sodium hydroxide with

the V*-lactone (10) .

(10) W. W. Pigman and R, M. Goepp, "Chemistry of Carbohydrates," Academic Press, Inc., New York 10, N. Y., 1948, p. 297.

C. Preparation of D- Gluconic and D-Galactonic Acids

D-Gluconic and D-galactqnic acids can be made by

chemical means, but for the most part the techniques are unsatisfactory for commercial operations. On the other

hand, fermentation methods have been developed to a point where high yields of D—gluconic and D—galactonic acids

can be obtained. The means of carrying out the prepara­

tion of aldonic acids both by fermentation and chemical methods are discussed in the following sections.

1. Commercial Preparation of D-Gluconic Acid by Fermentation Methods.

The conversion of fi-glueose into fi-gluconic acid

by fermentation methods was first accomplished by the oxidizing action of Acetobacter aceti (11). Certain

(11) L. Boutroux, Compt» rend., J2i? 236 (IBBO); A. J. Brown, J. Ghem, Soc., A2? 172, 435 (1886),

strains of Aspergillus niger were shown by Molliard,

in 1922, to exhibit a similar oxidizing action on £-

glucose. Later, Bernhauer (12) found that the conditions

(12) K. Bernhauer, Biochem. Z., 01, XXII, 296, 312, 324 (1926).

of the experiment were very important in determining the

product. Thus, by controlling the pH of the culture

medium and the temperature, and by a proper choice of

inorganic nutrient salts, he found it possible to obtain

good yields of either D-gluconic or citric acids at will.

Molds of species of Aspergillus are particularly suitable

for large scale production of D-gluconic acid, its lactones

and salts. Yields of 90 to 99^ of ^-gluconic acid are

obtained when fermentation of D-glucose with Aspergillus

is carried out under air pressure in rotating drums (13).

(13) A. J, Moyer, P. A. Wells, J. J. Stubbs, H, T, Herrick and 0. E. May, Ind. Eng. Chem., 2^, 77 (1937); E. A. Gastrock, N, Porges, P. A. Wells and A. J. Moyer, ibid.. 782 (1938); H. Porges, T. F. Clark and S. I. Aronovsky, ibid. . 22, 1065 (1941

The Pénicillium species are also an active Ê—gluconic

acid-forming group of molds (14)* They are unusual,

(1 4) J. H, Porter, "Bacterial Chemistry and Physi­ ology," John Wiley, Hew York, N. Y., 1946, p, 999. — 9— inasmuch as they apparently have no other action on jD-glucose, nor do they oxidize gluconic acid to form

other products. The action of the bacterium Subcxvdans

as an oxidizing agent of D-glucose is less selective than

that of the other molds mentioned. ^-Gluconic acid is

formed initially and is converted subsequently to the

5-keto acid by Acetobacter suboxidans (15).

(1 5) J. J. Stubbs, L, B. Lockwood, E, T, Roe, B. Tabenkin and E. Ward, Ind. Eng. Chem.^ 32. 1626 (194-0) J A. J, Kluyner and A. G. J, Boezaardt, Rec. trav, chim., 609 (1938).

The action of the enzyme Glucose oxidase was first

discovered by Maximow and its action on D-glucose was

studied later by Millier (16). It transforms D-glucose

(1 6) K. A. Maximow, Ber., deut, botan. Ges., 22. 225 (1904.); D. Müller, Biochem. Z., 122., 136 (1928)| cf. J. B. Sumner and K. Ityrback,The Enzymes," Vol. II, Part I, Academic Press, Inc., Publishers, New York, N.Y., 1951, pp. 764-767.

to D-gluconic acid. The raw materials for the commercial

production of ^-gluconic acids are refined corn sugar

and calcium carbonate along with boron compounds. The

presence of boric acid or borax in addition to the cal­

cium carbonate has been found to prevent precipitation

of calcium D-gluconate (17). The chief Interest in D-

(17) A. J, Moyer, E. J. Umberger and J, J. Stubbs, Ind. Eng. Ghem., 22, 1379 (1940). - 10- gluconic acid has centered in its calcium salt, an assimilable source of calcium both for human and animal needs (18).

(IS) Rothin and Schweiz, Med. Wochen., 22.» 38S (1927); Kottman and Schweiz, ibid. . 21, 409 (1927).

2, Preparation of D-Galactonic Acid D-Galactonic acid and its y —lactone are prepared on a very small scale. Two reasons for this are high cost and lack of demand. One of the starting materials which is used for the production of D-galactonio acid or its lactone is whey, a by-product in the manufacture of cheese. On being evaporated, whey deposits crystalline lactose (19), and the latter, subjected to mold fermen-

(19) F. P, Nebenhauer, Ind, Eng, Chem., 22, 54 (1930); E. 0, Whittier, Ghem, Revs., 2, 85 (1925). tation, has been found to produce D-gluconic and D-galac- tonic acids (20). Acetic acid bacteria have also been

(20) H, Knobloch and H. Moyer, Biochem. Z., 307, 285 (1941). found to oxidize D—galactose to D-galactonic acid (21)

(21) J, R. Porter, "Bacterial Chemistry and Physiology," John Wiley, New York (1946), p, 814.

Another source of D-galactonic acid and the iT-lactone -Il­ ls galaotan-bearing plants, such as agar-agar, or the

Western larch (22), D-Galactono—S-lactone has not been

(22) S. Acree^ U, S. Patent 1,816,136 (July 28, 1931). prepared In the crystalline state although a solution of

It may be obtained by oxidation of D-galactose with bro­ mine water In the presence of a buffer (23).

(23) H, S. Isbell and H. L. Frush, Bur. Standards J. Research, 332 (1932).

3. Chemical and Electrolytic Methods of

Preparing Aldonic Acids

The Killanl (24) or cyanohydrln synthesis provided

(24) H. Killanl, Ber., i£, 767 (1886).

one of the earliest known chemical methods for preparing an aldonic acid having one more carbon than the parent aldose. Under alkaline conditions, the oxygen of the air was shown to react with reducing sugars (25). Nef and

(25) H, Killanl and H. Sanda, Ber., 2^, 1650, 1654 (1893).

collaborators (26) found that very rapid streams of air

(26) J. U. Nef (and Lucas), Ann., 376, 55 Note (1910)5 Spoehr (and Rosario), Am. Ghem. J., 42* 240 (1910)• — 12 — passed through an alkaline solution of ^-glucose pro­ duced D-arabonolactone, This reaction represents a cleavage of the 1,2—eaediol common to a hexose with the formation of a five carbon aldonolactone. By carrying out the oxidation with pure oxygen, Spengler and

Pfannenstiel (27) found that yields rose to 60 to 15%

(27) 0, Spengler and H, Pfannenstiel, Z. Wirt- schaftsgruppe Zucherind, Tech, Tl, 54-7 (1935). of the theoretical.

The oxidation of aldoses by iodine in alkaline solution was first employed in principle by Romijn (23).

(23) G. Romijn, Z. anal. Chem., 349 (1397),

WillstStter and Schudel (29) showed that under carefully

(29) R. Willstatter and G, Schudel, Ber,, 780 (1918). controlled conditions the oxidation with hypoiodite proceeded in a stoichiometric manner. Some of the diffi­ culties inherent in this method, namely, enormous fluid bulk, and difficulty of freeing the reaction product from the inorganic constituents, were partially overcome by using barium iodide-iodine and barium, hydroxide, and carrying out the oxidation in solutions of higher con­ centration (3 0)..

(30) ¥. F. Goebel, J. Biol. Chem., %2, 809 (1927). - 13- The oxidation of D-glucos© to D-gluconic acid by chlorine under acid conditions was first done by Hlasi- wetz (31)* Bromine was also found to convert aldoses to

(31) H, Hlasiwetz, Ann, , 112, 281 (1861). aldonic acids (3 2), Further studies of this reaction

(32) H. Kiliani and S. Kleeman, Ber., 12, 1296 (1884), showed that the accumulation of hydrobromic acid, a by­ product of the reaction, retarded the rate of oxidation*

This inhibiting influence of hydrobromic acid was mini­ mized by carrying out the reaction in the presence of a buffer such as barium carbonate or barium benzoate (33)*

(33) H, A, Clowes and B. Tollens, Ann., 310. 164 (1899); G. S, Hudson and H, S. Isbell, J, Am, Chem, Soc,, 4, 2225 (1929)5 J, Research Natl, Bur, Standards, 2, 57 f1929).

The hypobromite oxidation was greatly simplified by Isbell (34), who produced the hypobromita ion by

(3 4) H, S, Isbell and H. L. Frush, J, Research Natl, Bur, Standards, 1145 (1931)5 H. S, Isbell (to the Government of the Ü, S,, represented by the Secre­ tary of Commerce), U. S, Patent %,976,731 (Oct, 16, 1934)► continuous electrolysis in a sugar solution containing a small amount of bromide ion, hydrobromic acid being the reduction product and this in turn being electrolysed — 14-“ to form again hypobromite ion. This process is practi­ cally never used. If the electrolytic method is not well controlled, saccharic and 2-keto and 5-keto aldonic acids are produced (35).

(35) R. Pasternack and P. P. Regna (to Charles Pfizer & Co.). U. S. 2,222,155 (Nov. 19, 194-0); E, W. Cook and R, T, Major, J. Am, Ghem, Soc,, 57f 773 (1935).

D. Preparation of Aldonamides

Aldonamides have been prepared in the following ways:

(a) By the solution of lactones in aqueous ammonia (36),

(36) C. 8. Hudson and S, Komatsu, J. Am, Chem, Soc,, 41, 1141 (1919).

(b) By the treatment of alcoholic solutions of lactones with ammonia gas (37).

(37) M, R, A. Weerman, Rec. trav, chim,, 37, 24 (1918).

(c) By the reaction of acetylated nitriles with hydrogen halide in glacial acetic acid (38),

(38) G, Zemplen and D, Kiss, Ber., 6Q, 165 (1927),

(d) By the solution of lactones in liquid ammonia and subsequent evaporation of the latter (39),

(39) J, W. E, Glattfeld and D, Macmillan, J. Am, Chem, Soc., i6, 2481 (1934). - 15 -

E» Preparation of Sugar Nitrates

1# General The chief methods available for the preparation of sugar nitrates are by the nitration of sugars with any of the following;

(a) A mixture of nitric and sulfuric acids at 0° (40).

(40) W. Will and F. Lenze, Bar., J^l, 68 (1398); J, A. Wyler (to Trojan Powder Co.). Ü, S, 2,039,045 and 2,0 3 9 ,0 4 6 (Apr. 28, 1936).

(b) 100% nitric acid at 0° (41)*

(4 1) P. Vieille, G. rend., 21, 13 5 (1382); Mem. poudres 2, 212 (1884-9).

(c) Water—free nitric-glacial acetic acids, or water- free nitric-glacial acetic acids and acetic acid an­ hydride (4 2).

(4 2) E. Berl and W. Smith. Ber., àQ, 903 (1907); Al, 1837 (1908); E. Berl, Ü. S. Patent 2,384,415 (Sept. 4, 1 9 4); 5 C. Trogus,. Ber., 64, B , 405 (1931).

(d) Nitric acid-phosphorus pentoxide (43,44).

(4 3) Warren, Ghem. News, 239 (1896).

(4 4) G. Lunge and E. Weintraub, Z. angew, Ghem., 12, 445 (1899). — 16—

(e) Nitric-phosphoric acids and phosphorus pentoxide

(45).

(45) E. Berl and G. Rueff, Ber., 63 B . 3212 (1930): Cellulosechem., 12, 53 (1931); lA, 115 (1933); E. Berl, Ind. Eng, Ghem. Anal, Ed., 1^, 322 (1 9 4I),

(f) Nitrogen tetroxide, sulfuric acid and a small amount of nitric acid (4 6),

(4 6) L, A. Pinck, J, Am, Ghem. Soc., 2536 (1927); Ind. Eng. Ghem., 12, 1241 (1930).

(g) Nitrogen pentoxide in non-aqueous solvents and con­ temporaneous elimination of nitric acid from the solution with phosphorus pentoxide (47).

(4 7) G, V. Caesar (to Stein, Hall & Go., Inc.), U, S. 2,400,287 (May I4, 1946).

(h) Nitrogen pentoxide in the presence of sodium fluoride

(4 8) .

(4 8) G. V. Gaesar and M, Goldfrank, J. Am, Ghem, Soc., 372 (1 9 4). 6

Will and Lenze (40) prepared, in crystalline form,

L-arabinose tetranitrate, D-mannose pentanitrate, and

D-galactose pentanitrate from the corresponding sugars and nitric-sulfuric acids. They also prepared, in non- crystalline form, ^-xylose tetranitrate and D-glucose pentanitrate by the same method. The structures of these -17- nitrates were not determined. A disadvantage of this method is the difficulty of purifying the sugar nitrates,

Wyler (4 0) claimed that the addition of an organic solvent to the nitrating solution facilitated the removal and purification of the sugar nitrates. Nitration with nitric- sulfuric acids has been extended to the preparation of nitrates of a few of the simple aldonic acids and their esters. Duval (49) prepared crystalline glycolic acid

(4 9) M. H. Duval, Bull, soc. chim., 22, 6 0I (1903); Compt. rend., ]J2, 571, 1262 (1903). nitrate, glyceric acid dinitrate, and methyl glycolate nitrate (in liquid form) using this method. Propyl glycolate nitrate (in liquid form) has been prepared from propyl glycolate and nitric-sulfuric acids (50),

(5 0) S. E. Forman, G. J. Carr and J. C. Krantz, Jr., J. Am. Pharm, Assoc., 132 (1941).

Nitration of sugars with nitric acid and acetic an­ hydride has been used to a very limited extent. It is

claimed that the method can be very dangerous because of the formation of acetyl nitrate which explodes at elevated temperatures (51). Recently, Filbert (52) claimed that

(5 1) E. Ott, "Cellulose and Cellulose Derivatives," Interscience Publishers, New York, N« Y., 1946, p. 635.

(5 2) W. F . Filbert (to E. I. du Pont de Nemours & Co.). U. S. 2,4 4 3 ,9 0 3 (June 22, 1948). -18-

he prepared partially nitrated ^-glnconamide by nitrating

£-gluconamide with nitric acid and acetic anhydride.

The fact that the compound had a low nitrate nitrogen

content of 15.83% indicated that, at best, he had a

mixture of partially and fully nitrated ^-gluconamide.

Uitric-phosphoric acid in the presence of phosphorus

pentoxide is a powerful nitrating medium. Cellulose

nitrated with such a nitration mixture shows very little

degradation, and the resulting highly nitrated cellulose

has been found to be suitable for viscosity determina­

tions (45).

Pinck (4 6) found that cellulose could be partially

nitrated with nitrogen tetroxide and sulfuric acid.

The sulfuric acid serves as a dehydrating reagent and

also forms nitric acid, ^ situ, as shown in the follow­

ing equation, OH N..0 . + H_8Q . SO., + HNOo d A 2 4 4- 2 ^ QjjQ ^

 serious disadvantage of the method is the fact that

only half of the nitrogen tetroxide is available as

nitric acid, 2. Nitration of Carbohydrates with Nitrogen

Pentoxide

(a) Nitrogen Pentoxide

In 1 8 4 0Deville discovered that nitrogen pentoxide,

NgOg, or nitric anhydride, was formed when dried chlorine -19- was passed over dried silver nitrate (53). Nitrogen

(53) H, St. C, Deville, Compt. rend., 2^, 257 (1849); Ann. chim. phys., [3], 2&, 241 (1850). pentoxide was also made by the action of ozone on nitrogen tetroxide. It is, however, made most con­ veniently by distilling anhydrous nitric acid with phosphorus pentoxide.

Nitrogen pentoxide is a colorless solid which

sublimes without melting. Since it begins to decompose into nitrogen tetroxide and oxygen at any temperature above 0®, its melting point cannot be very exactly de­ termined, but it appears to have a vapor pressure of 1 atmosphere at 32.5° and to melt at 41°. It may be kept for a month in diffuse sunlight without undue decomposi­ tion, if the temperature does not exceed 8°.

(b) Use of Nitrogen Pentoxide as a Nitrating

Agent

The literature covering the use of nitrogen pentoxide as a nitrating agent is meagre, Gibson (54)> in 1908,

(54) Gibson. Proc. Eoy. Soc, Edinburgh, 705 (1908)» nitrated tartaric acid with nitrogen pentoxide, and

Dufay (55) claimed advantages for it in nitrating cellulose,

(55) A. Dufay, Ghem, News, ig6, 211 (1912) -20-

Haines and Adkins (56) nitrated certain aromatic compounds

(56) L, B. Haines and H. Adkins, J. Am, Ghem. Soc,, 42, 14.19 (1925). with nitrogen pentoxidej Rogovin and Tikhonov (57) tested

(57) (a) Z. Rogovin and K, Tikhonov, Iskusstvennoe Volokno, 1, No, 7, 41 (1934); 1, No, 5, 34 (1934); (b) Cellulosechem., 16, 11 (1935); M, 102 (1934)► the effect of additions of nitrogen oxides, inclusive of pentoxide, to nitric acid in nitrations of cellulose;

Dalmon, Chedin and Brissaud (58) nitrated cellulose with

(58) R, Dalmon, J, Chedin and L, Brissaud, Compt, rend,, 2(^1, 6 6 4 (1935). nitrogen pentoxide in solution in carbon tetrachloride;

Dalmon (59) passed this reagent through dried cotton,

(5 9) R. Dalmon, Compt, rend., 201, 1123 (1935).

Urbanski and Janiszewskl (6 0 ) nitrated cellulose and

(6 0 ) T, Urbanski and Z, Janiszewski, Roczniki Chem., 12, 3 4 9 (1937). starch with "gaseous” or "liquid” pentoxide,

Caesar (47) prepared the nitrates of starch and cellulose with nitrogen pentoxide and eliminated the by­ produce of the reaction, nitric acid, with phosphorus pentoxide. Of especial interest is the fact that he ”-2X“-

prepared dinitrodimethyloxamide from dimethyloxamide

and nitrogen pentoxide in the presence of phosphorus

pentoxide. In 1946, Caesar and Goldfrank (48) reported

the use of sodium fluoride as a bonding agent for the

nitric acid, a by-product formed in nitration of a

hydroxy compound with nitrogen pentoxide,

F, Ftillv 0—Ester if led Aldonic Acids

Of the various 0-esters of aldonic acids which have

bee n prepared, the acetyl derivatives are the only ones

which have been investigated extensively. The benzo­

ate, propionate, and butyrate esters (61,62) have

(61) W, W, Lake and J, W, Glattfeld, J, Am, Chem, Soc,, 66, 1091 (1944). (62) M, Tishler (to Merck & Co,), Ü, S, 2,424,341 (July 22, 1947),

received very limited study, and, as a result, will not

be further discussed.

Interest in fully aeetylated aldonic acids was

stimulated by Maj or and Cook (63) through the preparation

(63) R, T, Major and E. W, Cook, J, Am, Chem, Soc,, 2477 (1936),

and application to syntheses of acid chlorides of these

acids. The great utility of fully aeetylated aldonic acids as intermediates in the syntheses of new compounds was demonstrated by Wolfrom and co-workers who used “•22“ these compounds in the preparation of ketoses (64.), 1—

(64.) M. h . Wolfrom, D, I, Weisblat, ¥. H, Zophy and S, W. Waisbrot, J, Am. Chem, Soc,, 201 (1941)* deoxy ketoses, 2-deoxy aldonic acids (65), aldehyde

(6 5) M. L. Wolfrom, S, W, Waisbrot and R. L. Brown, J, Am. Ghem, Soc,, 6 4, 1701 (1942),

(open-chaln) sugar acetates (66), and polyesters (67),

(66) M. L. Wolfrom and J, V. Karabinos, J, Am, Chem, Soc., §0, 1455 (1946), (67) M. L, Wolfrom and P. W, Morgan, J. Am. Chem. Soc,, 2026 (1 9 4), 2

The development of general methods of preparation of fully aeetylated aldonic acids was a prerequisite to their utilization in syntheses. Hurd and Sowden (68)

(68) C, D. Hurd and J, C. Sowden, J. Am, Chem, Soc., 6Sl, 235 (1938), prepared aeetylated aldonic acids by employing the following sequence of steps; aldose aldose oxime --- ^ acetylaldononitrile — —^ acetylaldon- amide --- ^ acetyl aldonic acid. The first two reactions involved the Wohl method of degradation. Precedent also existed for the next step, inasmuch as the reaction of

D-glucononitrile pentaacetate with hydrogen bromide in glacial acetic acid had been reported by Zemplen — and Kiss (33) to produce £-gluconamide 0-pentaacetate.

Treatment of the aeetylated aldonamides with nitrous anhydride produced the aeetylated aldonic acids, A more easily carried out general method for the prepara­ tion of a fully aeetylated aldonic acid was that developed by Wolfrom and co—workers (6 9)► This method, which gave

(69) M, L. Wolfrom, M. Konigsberg and D. I. Weisblat, J. Am. Chem. Soc,, 574 (1939). excellent results, may be illustrated by the following sequence of reactions.

GOBBg GONEg t ACgO (CHOAc) Aldono- -lactone ÏÏH- (CHOH), n o r ê -lactone 100 # CHgOH GH^OAc or ZnCl,

TT

COOH t NOCl (CHOAc) or t ] NOBr CHgOAc

III

The lactone was converted to the aldonamide (I) by the action of liquid ammonia, following the procedure of Glattfeld and Macmillan (39). Treatment of the aldon­ amide with acetic anhydride in the presence of a catalyst, such as zinc chloride (70), led to the formation of the —24—

(70) J, B. Robbins and F. W. Upson, J. Am, Chem. Soc., âS, 1788 (1938).

0-acetylated aldonamide (II). The latter was readily

deaminated with nitrosyl chloride or bromide to yield

the fully aeetylated aldonic acid (69). Wolfrom and

CO—workers (69) found that a very convenient method of preparing nitrosyl chloride was by passing dry sulfur dioxide gas into cold fuming nitric acid and subsequently drying the crystalline mass of nitro sulfuric acid. The latter, when heated with sodium chloride, liberated nitrosyl chloride, Wolfrom and co-workers have demon­

strated the wide applicability of this method by the preparation, in good yield, of the fully aeetylated acids

of ^-mannonic, D—gluconic, and J*-galactonic acids (69,

71). It is this general method which was applied in the

(71) M. L. Wolfrom, J. M. Berkebile and A. Thomp­ son, J. Am. Ghem. Soc., %1, 2360 (1949)»

syntheses of the fully nitrated aldonic acids described

in the experimental section.

6, Reaction of Dlazomethane with Sugar Acids

1» Diazomethane

Diazomethane is a yellow, odorless gas which boils at —23° and freezes at -145®, It is very poisonous and attacks the skin, eyes and lungs. In either the gaseous -25- or liquid forms it is very explosive, dissociating to form ethylene or polymethylenes, (GS^)^, and nitrogen

(72), It is stable, in the gaseous state when entrained

(72) H, von Pechmann, Ber., 21* 956 (1900), in ether,

Diazomethane was discovered by von Pechmann in 1894»

He produced it by the action of alcoholic potassium hydroxide upon ethyl N-methyl N-nitroso carbamate (73),

(73) H, von Pechmann, Ber,, 1888 (1894) *

Other methods of preparation of diazomethane are:

(a) By the action of methyl dichloramine on hydroxylamine hydrochloride in the presence of sodium methoxide (74)»

(74) E. Bamberger and E. Renauld, Ber., 2%, 1683 (1895),

(b) By the interaction of potassium hydroxide, hydrazine and chloroform (75),

(75) H. Staudinger and 0, Kupfer, Ber., 45^ 505 (1912),

(c) By the decomposition of nitrosomethylurethane with sodium glycolate (76),

(76) H. Me er we in and W. Burneleit, Ber,, 63^, 1845 (1928), —2 6—

(d) By the action of sodium isopropoxide on the nitroso derivative of the addition product of mesityl oxide and methylamine (77),

(77) E. C, 8. Jones and J, Kenner, J, Ghem, Soc,, 363 (1933); D, W, Adamson and J, Kenner, J, Chem, Soc,, 286 (1935).

(e) By the decomposition of N-methyl—N-nitroso-N- nitroguanidine with aqueous potassium hydroxide (78),

(78) A. F, McKay, J, Am, Chem, Soc., 2Ü, 1974 (1948).

(f) By the action of potassium hydroxide upon nitroso- methylurea in an ether solution (79).

(7 9) F. Arndt and J. Amende, Z. angew, Chem,, 43. 444 (1930); F, Arndt and H. Scholy, ibid,, Aà, 47 (1933); F, Arndt, "Organic Syntheses," Vol. XV, John Wiley & Sons, New York, N. Y., 1935, pp. 3, 48,

(g) By the interaction of alcoholic potassium hydroxide on N-nitroso*=N-methyl-£—toluene-sulfonamide in ether solution (80), The starting material is stable,

(80) H. J. Backer and Th, J. de Boer, Proc. Koninkl. Nederland. Akad. Wetenschap., 54 B, 191 (1951); of, C, A., 4 6, 1 9 6 1 (1 9 5), 2

The question of the structures proposed for diazo* methane has been discussed by Audrieth (81); the

(81) L. F. Audrieth, Ghem, Eevs., Ü , 175 (1934) —27» preponderance of evidence appears to favor a linear structure, CH^ H N, which in modern formulation would be represented as containing a semipolar double bond CHg • ' N „ui.,iN N,

2» Action of Diazomethane on Aldonic Acids

The first single investigation in the application of diazomethane to sugar chemistry was carried out by

Brigl and co-workers (82), For almost a decade no further work was reported until the school of Wolfrom.

(82) P, Brigl, H, Mtihlschlegel and R. Schinle, Ber., 6 A, 2921 (1931). began an extensive series of investigations on the use of this reagent upon acyclic sugar derivatives (6 4,6 $),

Fully ssterified aldonic acids have been successfully transformed into the corresponding methyl ester deriva­ tives by the action of diazomethane in ether solution

(S3)*

(83) G. B. Robbins and F. W. Upson, J, Am. Chem, Soc., 1074 (1 9 4) 0 ; M. L. Wolfrom and H. B, Wood, J. Am. Chem. 6 0 c., 730 (1951).

H. Stabilizers of Nitrated Carbohydrates

The literature dealing with the stability of sugar nitrates is very limited. Hitrate esters of B-arabinose,

D-mannose, ^—glucose and maltose decompose when stored —28—

at a temperature about 50° (8 4). This instability is

(8 4) T. L . Davis, ®The Chemistry of Powder and Ex­ plosives,” Vol. II, John Wiley & Sons, Inc., New York, N. Y., 1943, p. 238.

due to the nature of the nitrate group on carbon one.

It is an acylal and not a simple ester. Eoenigs and

Enorr (85) showed that the nitrate group of tetra-0—

(8 5) W. Koenigs and E, Knorr, Ber., 2A* 957 (1901).

acetyl a-fi—glucopyranosyl nitrate (86) was replaced by

(86) Colley, Compt. rend., %6, 436 (1873).

an alkoxy group with Walden inversion. Recently, Bris­

saud and Fleury (87) prepared the pentanitrates of a-

(87) G. Fleury and L. Brissaud, Compt. rend., 222, 1051 (1 9 4). 6

and p-D-glucopyranose in crystalline form and found

that the compounds had poor stability.

The stability of cellulose nitrate has been studied

extensively since Schbnbein announced his discovery of

guncotton in I8 4 6. The spontaneous decomposition of

cellulose nitrate in the air produces nitrous and nitric

acids which promote a further decomposition. If these

products, however, are removed continuously, the -29- uncatalyzed décomposition is extremely slow (88), The

(88) T, L, Davis, "The Chemistry of Powder and Ex­ plosives,” Vol. II, John Wiley & Sons, Inc», New York, N. Y. , 194.3, p. 307^ removal of acids is provided by intimately blending with

the nitrate a substance which reacts with and removes

them, but which does not by itself, nor in its combined form resulting from its reaction with thé acids liberated

in the decomposition, attack the cellulose nitrate.

Such substances are generally of a slightly basic character

or possess some kind of chemical unsaturation (89). Sub—

(89) E. Berger, Bull. soc. chim., Ü [4], 1049 (1912)

stances of pronounced basicity, however, are useless as

stabilizers because they decompose the cellulose nitrate

(90)» Other properties desirable in stabilizers include

(90) R,. Angeli, Z, ges. Schiess-u. Sprengstoffw, 12, 113 (1938)» compatibility with the carbohydrate nitrate, low volatil­ ity, low solubility in water, and a melting point well below 100® (91). Diphenylamin© has been used on a large

(91) V. R. Grassie, L. Mitchell, J. M. Pepper and 0. B. Purves, Can. J. Res., 2^ , 4 6 8 (1950)» scale as a stabilizer of cellulose nitrate (88) but now has to compete with Centralite (symdiethyldiphenylurea), “•3 0— which, is more compatible with cellulose nitrate (92)*

(92) D, Florentin, Z, ges, Schiess-u. Sprengstoffw, 6 (1913); cf. C, A., 2, 1290 (1913).

The individual sugar nitrates have been stabilized by diphenylamine, and certain ones of them, specifically the nitrates of maltose, lactose, and sucrose, have been able, by means of that substance, to find a limited in­ dustrial application (8 4). A few of some other substances which have been used to delay the onset of the dangerous autocatalytic second phase of decomposition of cellulose nitrate are carbazole (93) and dimethylanillne (94)*

(9 3) R, Dalbert, Mem. poudres, 2^, 147 (1938); cf. G. A., 21, 7569 (1939).

(9 4) J. water, Z. angew. Chem,, 24., 62 (1911).

I. Stability Tests of Nitrated Carbohydrates

Stability tests, sometimes called "heat tests," are applied to explosives to determine their stability or keeping qualities (95). During the process of manu-

(95) A. P. Sy, J. Am. Chem. Soc., 21, 549 (1903). facture, these tests are made to determine if the product has been sufficiently purified, i.e., freed from sub­ stances which might cause it to decompose spontaneously.

The more important and most used of the old stabil­ ity tests for cellulose nitrate powders are (95): —31— (a) The Potassitua-Iodide—Starch, or Abel Test

A sample of the nitrate is placed in a test tube

in which there is suspended a test paper of potassium

iodide-8taroh, moistened to one-half its length with a

50$ glycerine solution. This tube is then heated and

the test is ended at the appearance of a brown or blue

line on the test paper. The discoloration of the test paper is due to the action of free iodine on starch,

the iodine being liberated from the potassium iodide by impurities or products of decomposition.

(b) The Zinc-Iodide-Starch Test

This is a modification of the test just described,

zinc iodide being used instead of potassium iodide,

(c) The Guttmann Test

Instead of using a potassium iodide-starch paper,

Guttmann recommended a test paper moistened with a solu­ tion of diphenylamine in sulfuric acid,

(d) The Explosion Test

A small sample of the explosive (usually 0.1 g.) is placed in a strong test tube which is then tightly corked and placed in a paraffin bath at 100°. The bath is then stirred and heated so that the temperature in­ creases 5^ per minute. The temperature at which the sample explodes is noted. “•32“

J. Double-Base Powders and Films

The name of double-base powder (96) is reserved for

(9 6) T. L, Davis, "The Chemistry of Powder and Ex­ plosives," . Vol. II, John Wiley & Sons, Inc., New York, K. Ï., 1 9 4, 3 p. 298. such powders as ballistite and cordite which contain cellulose nitrate and glycerol trinitrate (or perhaps some substitute for the latter), Ballistite, discovered by Nobel (97) consisted of a stiff gelatinous mixture of

(97) A. Nobel, Brit. Patent 14-71 (1888). glycerol trinitrate and soluble cellulose nitrate pre­ pared with the use of a solvent which was later removed and recovered. In 1889, Lundholm and Sayers (98) in-

(98) Lundholm and Sayers, Brit, Patent 10,376 (1889). corporated glycerol trinitrate and soluble cellulose nitrate by use of hot water. Cordite (99), an explosive

(9 9) Abel and Dewar, Brit, Patents 5614 and 11,664 (1889). developed by the British, was made by plasticizing in­ soluble cellulose nitrate with glycerol using acetone as the solvent.

Double-base powders are made both with and without volatile solvent, and are also capable of being modified —33— in all of the ways in which a single base powder may

be modified (96), Thus, we have double—base powders

made by incorporating Centralite and nitroguanidine

with glycerol trinitrate and cellulose nitrate. The

component nitrates and stabilizer are colloided with

solvent and may be extruded through dies to yield a

powder. Gelatinizing agents, of which the Centralites

are examples, are often incorporated with double-base powders in order to cause the materials to burn more

slowly. They reduce the amount of solvent which is need­

ed in the manufacture of the powder and also serve as

effective stabilizers*

A double—base film is composed of the same materials as double-base powders, namely, cellulose nitrate plasticized with polyhydric alcohol nitrates by means

of a volatile solvent. The clearness of the film is taken as a criterion of the mutual compatibility of the nitrates of which it is composed* —34—

III. EXPERIMENTAL

A. Synthesis of Methyl D-Galactonate Pentanitrate

1, Preparation of D-Galactonamide

D-Galactonamide was prepared from D-galaotono—

lactone and liquid ammonia under anhydrous conditions,

using a slight modification of the procedure developed

by Glattfeld and Macmillan (39). Before the crude

product was crystallized, it was pulverized and dried

first in an oven for one hour at 60® and then over phos­

phorus pentoxide at room temperature and under reduced

pressure. The crude, dry D-galactonamide (10 g.) was

dissolved as quickly as possible in water (&&. 300 ml*

at 25®) and to the solution absolute ethanol (or ethanol)

was added as rapidly as possible, with vigorous stirring,

until the cloud point was reached. The resulting solu­

tion was left stand overnight at 0®j yield, 8,5 g., m.p»

173®-174° (cor.). A second recrstallization of D-galactonamide from

water-8thanol (at 60®) was effected by using the same

method as described in the first crystallization; m.p,

174® (cor.). Recrystallization of D-galactonamide was also carried

out using a hot 6 0^ solution of methyl cellosolve in

water. -35- 2,. Attempted Nitration of D-Galactonamide

with Nitrlo-Sulfnric Acids

An attempt was made to nitrate D—galactonamide by

the use of concentrated sulfuric acid and 100% mitrie

acid prepared by distillation of a mixture of concen­

trated sulfuric and concentrated nitric acids (1:1 by

volume)•

D-Galactonamide (1.0 g.) was slowly added to 100%

nitric acid (5 g.) at 0®, followed by the addition of

concentrated sulfuric acid (10 g.). After the result­

ing solution was kept at 0—10® for 30 minutes, it was

slowly poured into an ice-water mixture and left for one

day. No precipitate appeared after this time.

After this nitrating solution was diluted with water,

attempts which proved unsuccessful were made to extract

the nitrate with either chloroform or ether.

3« Attempted Nitration of j^-Galactonamide

with Nitric-Acetj.c Acids

D-Galactonamide (1,0 g,) was added to a solution of

100% nitric (7.5 g , ) and glacial acetic acids (2,5 g, ).

After the resulting solution was left stand at 0-10®

for fifteen minutes, it was poured slowly into an ice-

water mixture and further left stand for one day. No

precipitate appeared after this time. Attempts to

extract the nitrate from the nitrating solution were —36— carried out in the same manner as described in Section

A, 2, but without success*.

4. Preparation of Nitrogen Pentoxide

Nitrogen pentoxide was prepared according to the procedure of Caesar and Goldfrank (4-^) with a minor modification, namely, the inclusion in the three-neeked reaction flask of a glass stirring rod which was operated by hand. This device permitted the reaction to be con­ trolled more uniformly and prevented any escape of oxides during stirring. Higher yields of nitrogen oxides were obtained than reported by Caesar and Goldfrank,

About 170 g, of 100^ nitric acid was placed in a three-necked reaction flask (capacity 5 1.) which was immersed in solid carbon dioxide and acetone, and an oxygen stream passed through the system for 15 minutes to remove moist air. When the nitric acid was frozen, about 220 g, of phosphorus pentoxide was quickly added.

The bath of solid carbon dioxide and acetone was removed from under the flask and replaced with a water bath at room temperature. Throughout the whole process, dry oxy­ gen was continually passed through the system. As the acid slowly melted, nitrogen pentoxide was produced by the reaction of nitric acid and phosphorus pentoxide.

The reaction was allowed to proceed at room temperature for about one hour. During this period the stirring -37- device was turned by hand at brief intervals of time*

This intermittent agitation was so controlled that the distillation of nitrogen pentoxide took place quite uniformly. When the distillation of nitrogen pentoxide had subsided, the water bath was heated slowly to 50—

6 0® for several hours until the reaction appeared to be substantially completed. Agitation of the reactants was continued as described before*

The warm water bath was then removed and oxygen allowed to circulate as before for about a half-hour,

A yield of about 100 g, of crystalline nitrogen pentoxide and nitrogen tetroxide was obtained* To the crystalline nitrogen oxides, contained in the receiver, about 6 0 0 g, of anhydrous ethanol-free chloroform was added, and the temperature allowed to rise to about 0° in order to ef"« fect complete solution of the former. The ethanol—free chloroform was prepared by washing a reagent grade of solvent 5 times with concentrated sulfuric acid, followed by water (to remove acidity), drying over calcium chloride, and finally, distilling under anhydrous conditions.

One ml* of the resulting solution of the nitrogen oxides in chloroform was pipetted into about 25 ml* of water and titrated with 0,1 N sodium hydroxide followed by 0,1 N potassium permanganate* All the reducing matter was calculated as nitrogen tetroxide. The nitrogen pentoxide was obtained by deducting the nitrogen tetroxide — *“3 s •" equivalent from the total acidity. The weights of nitrogen pentoxide and tetroxide per ml, of chloroform solution were calculated by means of the following equations,

(a) Wt. of NgOg = 0,0054 [(ml, NaGH) - (1,02 Xml . KMnO^)]

(b) Wt. of NgO^ = 0.0045 X ml. KMnO^

5. Synthesis of JD—Galactonamide 0—Pentanitrate

D-Galactonamide was nitrated with nitrogen pentoxide in the presence of sodium fluoride, using a minor modi­ fication of the method developed by Caesar and Goldfrank

(A-B) . The nitration solution contained 18 g. of nitrogen pentoxide and 2.5 g. of nitrogen tetroxide per 100 ml. of anhydrous ethanol-free chloroform solution.

Freshly prepared nitrating solution (750 g.) and sodium fluoride (12 g.) were placed in a three-necked flask equipped with a stirrer and thermometer, and after they were cooled to —5°, dry fi-galactonamide (9 g.) was added slowly with stirring. Nitration was allowed to continue for 35 minutes after the addition of all the amide, and during this time the nitration temperature was allowed to increase to a maximum of 16®. The average nitration temperature was about 14°.

The reaction mixture was filtered by suction on a sintered-glass funnel, and the D-galactonamide nitrate immediately washed with about 150 ml. of anhydrous —39- ethanol—free chloroform at 0°. To ensure complete re­ moval of the contaminants, namely, sodium fluoride and excess nitrating agent, the nitrate was made into a slurry with each of the following, respectivelyt three portions of chloroform at 0°, two portions of ice-cold water, four portions of water at 20°, and finally, five portions of water at 4-0—50°. After the nitrate was made into a slurry with each wash, suction was applied to remove the liquid. The crude nitrate was dried in a desiccator over sodium hydroxide pellets and phos­ phorus pentoxide; yield, 16,6 g, (66^); m,p., crude nitrate began to turn brownn at about 173° but did not melt.

Pure 2-galactonamide 0-pentanitrate was obtained by crystallizing the crude nitrate from methanol-water.

Sixteen grams of the nitrate was dissolved in about 600 ml. methanol at 20°, and the solution filtered. To the clear filtrate which was vigorously stirred, water, also at 20°, was added dropwise until the cloud-point was reached. The solution was allowed to stand at room temperature for about one—half hour, and then for three hours at 0°. Precipitation usually occurred very rapid­ ly to form an interlacing mass of long slender white crystals. A second recrystallization of the nitrate was carried out using methanol at 50°, followed by the slow addition of water at 6 0 ° until the cloud-point was reached. This resulted in the production of a nitrate which had the same melting point as that obtained after —4-0“»

a third recrystallization; m.p. 168® (dec,, cor,*), P — 28 L^J D + 13° (c 1.3, acetone), Galactonamide 0- peatanitrate was soluble in ethanol, methanol and dio-

xane. It was insoluble in ether, light petroleum ether,

chloroform and water.

Anal. Galea, for G^HgO^HCNOg)^^ G, 17,15; H, 1,92;

N, 20.01, Found: C, 17.23 (Er); H, 1,53 (Kr); N,

19.97 (El).

Analysts: Mrs, E. H. Klotz (El) and Mr. J. W,

Kraus (Kr) of The Ohio State University and Dr. E, Huff­

man (H), 505 Majestic Building, Denver 2, Colorado,

D—Galactonamide 0-pentanitrate was also recrystallized

from ethanol-water.

6. Synthesis of D-Galactonic Acid Pentanitrate D—Galactonamide 0-pentanitrate was deaminated with nitrosyl chloride in glacial acetic acid according to

a slight modification of the procedure of Wolfrom,

Konigsberg and Weisblat (69)*

D-Galactonamide 0-pentanitrate (10,7 g.) was dissolved

in glacial acetic acid (800 g.) contained in a round- bottomed flask. To the cold solution, which was exter­ nally cooled by ice, nitrosyl chloride (4-00 g. ) was slowly

* All melting points were taken on a Fisher-Johns melting point block and are corrected. All purified nitrates showed evidence of rapid decomposition at their melting points as they bubbled violently and oxides of nitrogen were detected by odor. No residue was visible after the nitrate had decomposed. -41” added. Excess nitrosyl chloride was allowed to escape through a fine capillary. The reaction mixture was agitated occasionally and kept at 0° for one hour. It was then permitted to warm gradually to room tempera­ ture. After the reaction was allowed to proceed for about 20 hours, the temperature of the reactants was o raised to 40 , and most of the nitrosyl chloride re­ moved by water suction. The solid residue, obtained on solvent removal with an oil pump, was dissolved immedi­ ately in 100 ml, of absolute ether and the solution filtered. The crude product decomposed slowly if not recrystallized immediately. Crystallization of the nitrated aldonic acid was induced by the slow addition of 500 ml. of absolute light petroleum ether. The tem­ perature of the solution was maintained at 0° for one day, whereupon a second portion of 5 0 0 ml. of light petroleum ether was added and the solution maintained at 0® for another day in order to effect a more complete crystallization of the nitrated aldonic acid; yield,

9.5 g. (88%). A second recrystallization was effected by dissolving the nitrate in excess absolute ether at its boiling point and subsequently slowly adding light petroleum ether, also at its boiling point, until the cloud-point was reached, and then maintaining the solu— o tion at 0 for one day; yield, 8.1 g., beautiful, slender, white crystals; m.p, 138° (dec., cor.), a + 21°

(c 3.7, acetone), JD-Galactonic acid pentanitrate was — ^ 2 —

soluble in ether, acetone, ethanol and dioxane. It

was slightly soluble in chloroform and was insoluble in benzene and water,

SslM. for C6Ey0Y(N02)g: C, 17,12; H, 1,68;

H, 16.63. Found: C, 17.31 (H); H, 1.82 (H);

N, 16.39 (Kl).

In a preliminary test run involving deamination of

D-galactonamide 0-pentanitrate, 20 g. of nitrosyl

chloride was used for 1 g. of nitrated amide. In this

case, a 71^ yield of the nitrated aldonic acid was ob­

tained,

7» Preparation of Diazomethane

The diazomethane used in this work was prepared by the action of potassium hydroxide upon nitrosomethylurea

in ether solution using the method described by Arndt

(79),

In a 50 ml. round-bottomed flask were placed 9 ml.

of 50^ aqueous potassium hydroxide solution and 25 ml.

of ether. After the mixture was cooled to —5^, 3 g. of nitrosomethylurea was added with shaking. The flask was fitted with a condenser set for distillation, the lower

i end of which carried an adapter passing through a two- hbled rubber stopper and dipping below the surface of

25 ml, of ether contained in a 100 ml, Erlenmeyer flask and cooled in an ice-salt mixture. The exit gases were passed through a second 25 ml. portion of ether, likewise —4-3— cooled to 0°. The reaction flask was heated in a water

bath at 50°, and the ether distilled until it came over

colorless. The solutions in the receivers were combined

and dried over solid potassium hydroxide pellets.

An alternate method of preparing small batches of

dry diazomethane in ether was as follows. The ethereal

solution of diazomethane was decanted from aqueous potassium hydroxide, dried over solid potassium hydroxide for one hour and then decanted from the drying agent, A

second drying was carried out in the same manner as be­ fore over fresh solid potassium hydroxide.

The dried ether solutions of diazomethane were

standardized by the following procedure. Approximately

1 g, of pure benzoic acid was weighed accurately and transferred to a 125 ml, Erlenmeyer flask. After the

addition of 50 ml, of ether, 10 ml, of the diazomethane

in ether solution was added to the flask from a pipet.

The excess benzoic acid was determined by back-titra-

tion with a 0,1 K sodium hydroxide using phenolphthalein

as the indicator. Solutions prepared as above usually

contained between 0,012—0,021 g, of diazomethane per ml,

of ether solution,

8, Synthesis of Methyl ^-Galactonate Pentanitrate A solution of D-galactonic acid 0-pentanitrate

(1,0 g., SJL» 0,00238 mole) in dry ether (10 ml,) was — 44 - pour ed slowly, with stirring, into 6,5 ml. of anhydrous ether containing diazomethane (0.00238 mole). There was a vigorous evolution of nitrogen gas during the addition of the ether solution of diazomethane, and crystallization took place soon after. The mixture was kept overnight at -10°; yield of first crop, 0,78 g,, m.p, 106-107° (dec., cor,), A second crop was obtained by evaporating the filtrate under suction to 6 ml,, and subsequently adding 20 ml, of light petroleum ether.

Crystallization of the product resulted on leaving the mixture stand overnight at -10°; yield of second crop,

0,18 g,, total yield, 0,96 g, (93%), Pure material was obtained by dissolving the methyl nitrate ester

(0,3 g,) in excess absolute ether (18 ml,), and then adding slowly light petroleum ether (50 ml,). Crystal­ lization of the product resulted when the mixture was left stand overnight at 0°; m.p, 107° (dec,, cor,),

+21° (c 3.6, chloroform). Methyl D-galactonate pentanitrate was soluble in chloroform, ethanol, ether and acetone. It was insoluble in light petroleum ether.

Anal, Calcd. for CYSqOy(NOg)^: 0, 19,32; H, 2,08; N, 16,10, Found: C, 19.4? (El); H, 2.04 (El);

N, 16,27 (Kr),

When excess diazomethane in ether was used, low yields of methyl esters were obtained and an oily by­ —45— product was formed. It was very difficult to separate the methyl ester from the oil and to make the former crystallize,

B. Synthesis of Methyl D-Gluconate Pentanitrate 1, Preparation of D-Gluconamide

D-Gluconamide was prepared from £—glucono-5—lactone and liquid ammonia under anhydrous conditions, using a minor modification of the procedure of Glattfeld and

Macmillan (39). The crude product was pulverized and dried thoroughly under vacuum over phosphorus pentoxide.

The dry D—glueonamide (30 g,) was quickly dissolved in water (300 ml.) at 25°, and to the solution, abso­ lute ethanol (1200 ml.) at 25° was immediately added as quickly as possible with constant stirring. Crude 2- gluconamide deaminates very easily in warm water. The solution was left stand overnight at 0°, whereupon crystallization took place; yield, 17.5 g., m.p. 143-

144° (cor,), A second recrystallization of D-gluconamide was carried out using warm solvents. To a solution of

D-gluconamide (10 g,) in water (100 ml. at 40°)^ absolute ethanol (ca, 400 ml, at 60°) was added slowly. Crystal­ lization took place when the resulting clear solution was left stand overnight at 0°; yield, 7,8 g., m.p, 144°

(cor,).

Crude £-gluconamide (2 g.) was also recrystallized — 4 6 — by dissolving it in a hot mixture of methyl cellosolve

(40 ml.) and water (20 ml.). After the solution was cool, absolute ethanol (50 ml.) was added with constant stirring and the solution left stand at 0® for several days, at which time crystallization was complete,

2* Synthesis of j^—Glueonamide 0—Pentanitrate D-Gluconamide (7,5 g.) was nitrated with nitrogen pentoxide (2.S moles per mole of hydroxyl of D-gluoon­ amide ) and sodium fluoride (7,5 g,) in a similar manner as described for the nitration of ^-galactonamide (see

Section A, 5); yield, 15 g, (93^), The crude nitrate was crystallized from methanol-water la the same way as described for the first crystallization of D-galacton­ amide 0-pentanitrate, A second recrystallization yielded a product with a melting point that did not change on subsequent recrystallization; m.p, 147® (dec,, cor,), + 37° (c 3,2, acetone). The purified nitrate was composed of very long slender, white crystals, £-

Gluconamide 0—pentanitrate was soluble in ethanol, methanol, acetone and dioxane. It was insoluble in ether, light petroleum other, chloroform and water.

Anal, Galcd, for G^Hg0^N(N02)^: C, 17,15; H, 1,92;

N, 20,01, Found: 0, 17.54 (Kl); H, 1,84 (Kl);

N, 19.86 (Kl),

During the research Involving the nitration of D— — 4 7 — gluconamide, the mole ratio of nitrogen pentoxide to hydroxyl of the amide, as wall as the age of the nitra­ tion solution were varied, A fresh nitration solution containing 2,3 moles of nitrogen pentoxide per mole of hydroxyl gave a nitrate having a nigrogen content of

19,86^, The same nitration solution was stored for o one day at -10 and then used to nitrate another batch of amide. In the latter case, the mole ratio of nitrogen pentoxide to hydroxyl was 1,75, and the resulting nitrate had a nitrogen content of 19*38%, A nitration solution which was stored in a refrigerator at about 0° for 8 days gave a nitrate in very low yield (about 15%). No attempt was made to analyse this material quantitatively but qualitative tests showed that it was a nitrate (a small sample exploded when heated in a test tube).

An attempt was made to recrystallize £—gluconamide

0-pentanitrate from ethanol-water but the method was abandoned as the nitrate showed a slight tendency to decompose in the ethanol.

3. Synthesis of D-Gluconic Acid Pentanitrate 2-Glueonamide 0-pentanitrate (10.4 g.) was deaminated with nitrosyl chloride (350 g,) in glacial acetic acid

(700 g.) in the same manner as described for the deamina­ tion of D«galaetonamide 0-pentanitrate, and the product was recrystallized from ether-light petroleum ether — 4 8 — using the same method (see Section A, 6)j yield, 8,7 g,

(83$). A second recrystallization, effected in the same manner as the first, yielded a product with constant melting point; m.p. 122° (dec., cor.) + 35°

(c 4.4, acetone). ^-Gluconic acid pentanitrate was com­ posed of long, slender, white crystals. It was soluble in ether, acetone, ethanol and dioxane, slightly soluble in chloroform, and insoluble in benzene and water.

Ana],. Galcd. for (NOg)^: G, 17,12; H, 1.68;

N, 16.63. Found: 0, 17.44 (Kr); H, 1.99 (Kr);

N, 16.55 (Kr).

Deamination of D-gluc onamide 0-pentanitrate (2 g.) with nitrosyl chloride (50 g,) in glacial acetic acid, under the same conditions as described above, gave £— gluconic acid pentanitrate in 65$ yield.

Crude D-gluconic acid pentanitrate showed a slight tendency to decompose at room temperature (judged by odor of oxides of nitrogen) and as a result, the crude product was immediately recrystallized.

4* Synthesis of Methyl ^-Gluconate

D—Gluconic acid pentanitrate (0.5 g., 0.00119 mole) was esterified with diazomethane (0.00119 mole) in ab­ solute ether (4.7 ml.) in the same manner as described for the preparation of methyl D—galactonate pentanitrate. —4-9— and the product was recrystallized from ether-light petro­

leum ether in the same manner (see Section A, 7); yield,

0,41 g. (Sl^)e A second recrystallization yielded a

product with constant melting pointj m.p, 58® (dec,,

cor.), + 34° (c 3.6, chloroform). Methyl D-gluco- nate pentanitrate was composed of long, white crystals.

It was soluble in chloroform, acetone and ether, and

insoluble in light petroleum ether.

Anal. Galcd. for (NO2)5s C, 19.32; H, 2.08; N, 16.10. Found: 0, 19.63 (Kr); H, 2.19 (Kr);

N, 16.41 (Kr).

C. Stability and Sensitivity of Nitrates

1. Determination of Stability of Nitrates

The stability of the nitrates was determined by using a test paper for detecting the instability of double-bass propellants. A strip of ethyl violet test paper (ça* 1" x I/I6 ") and about 0.1 g. of the nitrate, but no desiccant, were placed in a stoppered glass vial (capacity 5 ml,). The color changes in the test paper which took place upon storage of the nitrates in the dark are noted in Table I.

2. Determination of Sensitivity of Nitrates

The sensitivity of each nitrate to percussion was crudely determined by placing a few crystals of it on a metal surface (small vise) and then striking them -50-

TABLE I

STABILITY AND SENSITIVITY OF NITRATES

Stability Sensitivity Time Decompo- To per- Nitrate Temp, in days sition— cussion— To heat— D-Gala ctonamide 0-pentanitrate Crude 25-35 30 E + + Recrystallised 0 100 A + + 20-35 15 A 20-35 30 B D-Galactonic acid penta­ nitrate 0 50 A + + 2 0-35 16 A + + Methyl D-galac­ tonate 0-penta— nitrate 0 50 B + + 2 0-2 5 5 A 20-2 5 16 E

D-Gluconamide 0-pentanitrate Crude 25-35 30 E + + Recrystallized 0 100 A + + 20-2 5 20 A 20-35 20 B D-Gluconic acid pentanitrate 0 50 B + + 20-35 16 E Methyl D-gluco- nate penta­ nitrate 0 50 G + + 20-35 5 B 20-35 16 E

—Nitrate stored in stoppered vial with strip of ethyl Viiolet test paper. Letter indicates fraction of decolora­ tion: A, Oj B, 0-1/4; C, 1 / 4 - 1 / 2 ; D, 1/2-3/4; E, 3/4- 1, -ttPercussionS (+) indicates nitrate exploded when struck on small vise by hammer. ^Heat: (+) indicates nitrate exploded when heated gently in an open test tube* -51- with a hammer. A crude test for determining the sensi­

tivity of each nitrate to heat was carried out by placing a few crystals of it in an open test tube and then heating the sample very carefully behind an ex­ plosion screen. The results of these tests are also

shown in Table I.

D. Comoatabilitv of Nitrated Aldonic Acid

Derivatives and Cellulose Nitrate

1. Preparation of Films of Cellulose Nitrate

and Derivatives of Aldonic Acid Nitrates

Each nitrate in question (0,020 g,) was dissolved in reagent ethyl acetate (2 ml,) contained in a small

stoppered bottle (5 ml. capacity). Cellulose nitrate

(0,080 g,) having a nitrogen content of 12,6% was then added, and a homogeneous solution of the nitrates was effected by shaking the bottle at frequent intervals for one day. The bottle was protected from light to prevent any possible adverse effect of the latter on the nitrates,

The mixture (1,15 g.) was poured into a round flat- bottom evaporating dish (surface area 0.37 sq, inches) for film casting, and the solvent was evaporated at room temperature under atmospheric conditions and in the absence of direct light. After two days, the dry film was removed from the evaporating dish and stored

in a stoppered glass vial (5 ml. capacity). The films -52- were viewed under a microscope (Z 16 power) and their appearance in clearness compared with that of a con­

trol film made of cellulose nitrate only. The results

of these tests are indicated in Table II.

2. Preparation of Films of Cellulose Nitrate,

Aldonic Acid Hitrate Derivatives and

Diphenvlamine

Each nitrate in question (0,020 g.) and diphenyl- amine (O.001 g, or 1% by weight of total solids) were dissolved in reagent ethyl acetate (2 ml.) contained in a vial (5 ml. capacity). Cellulose nitrate (O.080 g.) having a nitrogen content of 12.6^ was then added, and the films prepared in the same manner as described in the preparation of double-base films which contained no stabilizer (see Section III, D, 1). The results of the tests, showing the effects of diphenylamine as a stabilizer of the nitrates, are shown in Table III.

3. Determination of Stability of Double-

Base Films

The determination of stability of the double-base films was carried out in a manner analogous to that used for the determination of stability of the nitrates (see

Section III, C, 1). The results of the stability tests on the films are shown in Tables II and III. -53- TABLB II

FILMS® OF ALDONIC ACID PENTANITRATE

DERIVATIVES AND CELLULOSE NITRATE

Stability Additive to Time in Decompo— Appearance^ film Temp,° days sition° of film

Control (Cellulose 0 10 A A nitrate) 20-35 10 A A Methyl D-galacton­ ate pentanitrate 0 10 B A 20-35 3 D 20-35 6 E A Methyl D-gluconate pentanitrate 0 50 0 A 20-35 3 D 20-35 6 E A

An amount of 0,08 g. of cellulose nitrate 0-2,6^) + 0,02 g, nitrate in 2 ml, of ethyl acetate, ^Nitrate stored in stoppered vial with strip of ethyl violet test paper. Letter indicates fraction of decoloration: A, 0; B, 0-1/4J c, 1/4-1/2; D, 1/2-3/45 E, 3/4-1. °When viewed under microscope (Xl6), A indicates clear with only a f ew spots and no crystals. —54" TABLE III

FILMS- OF ALDONIC ACID PENTANITRATE

DERIVATIVES AND CELLULOSE NITRATE

WITH DIPHENYLAMINE

Stability Additive to Time in Decompo- Appearance-! film Temp.° days sition— of film

Control (Cellulose 0 10 A A Nitrate) 20-35 30 A A D-Galactonamide 0-pentanitrate 0 10 B* A 20-35 30 C 20-35 45 D A D—Gluconamide 0-pentanitrate 0 10 B* A 20-35 30 D 20-35 45 E A Methyl D-galactonate pentanitrate 0 10 B* A 20-35 30 D 20-35 45 D A Methyl D-gluconate pentanitrate 0 10 B* A 20-35 30 D 20-35 45 D A

^An amount of 0.080 g. of cellulose nitrate (12.6%) + 0,020 g, nitrate + 0,001 g.. of diphenylamine in 2 ml. ethyl acetate. Film stored in stoppered vial with strip of ethyl violet test paper. Letter indicates fraction of decoloration: A, 0; B, 0-1/4; 0, l/4~l/2; D, 1/2-3/4; Ej 3/4-I* ^When viewed under microscope (Xl6) A indicates clear film with only a few spots and no crystals. *Value close to A, -55- IV. Discussion OF RESOLTS

A. General

As some sugar nitrates are known to decompose slowly

at 50°, and moreover, as some are easily exploded by

shock, it was deemed advisable to prepare initially,

on a micro scale, 2,-galactonic acid pentanitrate and

D-gluconic acid pentanitrate and their corresponding

derivatives. Since no particular difficulty was found

in handling and storing the aforementioned nitrates,

the work was repeated on a larger scale in which as

much as a twenty gram batch of the nitrate was produced

in one operation. In this paper the word "nitrate”

refers to an ©«substituted pentanitrate. Great care

was exercised in the manipulation of the nitrates as

their sensitivity to shock was unknown,

B . Preparation of Starting Materials

1. Preparation of ^-Galactonamide

D-Galactonamide was prepared under anhydrous con­

ditions from D—galactono- y-lactone and liquid ammonia

according to a minor modification of the procedure of

Glattfeld and Macmillan (39). The crude amide was first

dried at about 60® for one hour and then cooled to about

25®. The dry amide was quickly dissolved in water (25®)»

and crystallization was induced by immediately adding — 5 6 “ dropwise, with constant stirring, absolute ethanol

(also at 25 ). Subsequent recrystallizations were from warm water-ethanol ,as described above.

2, Preparation of D-Gluconamide

D—Gluconamide was prepared under anhydrous condi­ tions from D_—glucono- 5 —lactone, and crystallized by- employing the same method as used for the preparation and crystallization of galactonamide, D—Gluconamide was subject to easier deamination than galactonamide when using cold or warm solvent pairs. It was very essential that the whole operation of dissolving the amide in water (25^), followed by the addition of abso­ lute ethanol (either at 25° or at 4-0*“50°), be completed as rapidly as possible in order to prevent hydrolysis of D-gluc onamide *

3. Preparation of Nitrogen Pentoxide

The nitrogen pentoxide used in this work was prepared according to the procedure of Caesar and Goldfrank (4-8), employing phosphorus pentoxide upon white nitric acid

(100%). The nitrogen pentoxide, contaminated with about

20% by weight of nitrogen tetroxide, was dissolved in ethanol-free chloroform. The nitrating solution was standardized by titrating a sample with standard sodium hydroxide solution and another one with standard potassium -57- permanganate solution. The nitrogen pentoxide content

was calculated by deducting the nitrogen tetroxide

equivalent from the total acidity.

G. Preparation of A1donamide O-Pentanitrates

1. Attempted Nitration of Aldonamides with

Nj.tric-Sulfurie Acids

D—Galactonamide and D—gluconamide were nitrated

with 100^ nitric-sulfuric acids according to the pro­ cedure used by Will and Lenze (4-0), The nitrates were

soluble in the nitric acid and were not precipitated

by the addition of concentrated or fuming sulfuric acid.

Furthermore, the dispersion of the nitration solution

in an ice-water mixture failed to cause the nitrate

to precipitate, even after allowing the solution to

stand for one day at 0®. Extraction of the aqueous

nitrating solution with benzene, chloroform or ether,

and subsequent evaporation of the solvent in order to

isolate a nitrate were also unsuccessful; the product

was essentially insoluble an these solvents. The amide

might have been hydrolyzed to the acid, but if so, the

acid should have been ether-extractable.

2. Attempted Nitration of £-Galactonamide

with Nitric-Acetic Acids

A homogeneous solution resulted when D-galactonamide was added to nitric-acetic acids in the ratio of 3:1 at - 58 -

0®. When the resulting clear solution was poured into ice-water and left stand for one day, no nitrate cry­ stallized. Attempted extractions of the nitrate from the aqueous nitrating solution with either chloroform or ether also failed.

3. Preparation of Aldonamide 0-Pentanitrates

Using Nitrogen Pentoxide

fi—Galactonamide and D—gluconamide were fully nitrated with freshly prepared nitrogen pentoxide in dry ethanol- free chloroform in the presence of sodium fluoride which removes the hydrogen nitrate from solution. The reaction can be formulated by the following equation, COUH„,4 tCONHp ^ (CH O H ), , (GHOEfO^), + HNO^ V ^ iîaF . 2 4 3 GHgOE GHgONOg

The by-product of the nitration, nitric acid, was removed with sodium fluoride according to the procedure developed by Caesar and Goldfrank (48),

It was found that the aforementioned aldonamides were fully nitrated by employing a nitration mixture which contained from 2,1 to 2,8 moles of nitrogen pentoxide per mole of hydroxyl of the aldonamide. As the result of extensive research on nitration of starch with nitrogen pentoxide, Caesar and Goldfrank (48) concluded that the degree of nitration of starch could be varied at will. -59- and was dependent primarily upon the ratio by weight of nitrogen pentoxide to starch. At a ratio of about 2,5 or higher, they reported complete nitration under wide variations of time and temperature. This ratio, which they reported, viz,, 2,5, would correspond to a ratio of 1,25 moles of nitrogen pentoxide per mole of hydroxyl of starch. It is thus evident that further work is necessary to determine if D-galactonamide (or D-glucon­ amide) might be completely nitrated with a lower ratio by weight of nitrogen pentoxide to amide.

In the course of nitrating h^gluconamide, it was found that the age of the nitration mixture or the mole ratio of nitrogen pentoxide to hydroxyl (or a combination of the two parameters) were critical in determining the degree of nitration of the amide, A freshly prepared nitrating solution which contained 2,3 moles of nitrogen pentoxide per mole of hydroxyl gave a nitrate having a nitrogen content of 19.86^ (theor, 20,01^), A portion of the same nitration mixture was subsequently stored for one day at —5° to -10® and then used to nitrate another sample of the same amide. The one-day old nitration solution contained 1,75 moles of nitrogen pentoxide per mole of hydroxyl of the aldonamide and gave a nitrate having a nitrogen content of 19.38%, As the mole ratios of nitrogen pentoxide to hydroxyl were not kept constant in the two cases, it is impossible to say which factor. -60-

viz., age or amount of nitrogen pentoxide, was the more

critical. The usual nitration time range employed for

nitrating the aldouamidss was about 35 minutes after the

final addition of the amide to the nitrating solution,

The average nitration temperature was approximately 1^°,

A complete record of all nitrations carried out and

the concentrations of nitrogen pentoxide and nitrogen

tetroxide is not reported herein. It was found, however,

that satisfactory results were obtained with nitration

mixtures which contained from 15 to 21 g, of nitrogen

pentoxide and 3,7 to 5.0 g, of nitrogen tetroxide per

100 ml, of nitration solution, D-Galactonamide penta­ nitrate and 2,—gluconamide pentanitrate were obtained

in yields of approximately 90% when the nitration solu­

tion contained about 6 g, of nitrogen pentoxide per g,

of aldonamide,

Nitration with nitrogen pentoxide, according to the method described in the experimental section, was very

nearly anhydrous and the conditions of nitration were

relatively mild. It was surprising and pleasing to this

Laboratory to discover that nitration of an aldonamide with nitrogen pentoxide in the presence of sodium fluoride

produced the aldonamide 0-pentanitrate and not N- nitroaldonamide 0-pentanitrate, Caesar (47) reported

that he obtained dinitrodimethyloxamide by nitrating •“ 6 1 .“ dimethylexamide with nitrogen pentoxide in the presence of phosphorus pentoxide. Perhaps the mild agent, namely, sodium fluoride, used in our nitration, led to a selec­ tive nitration of the hydroxyl only.

The aldonamide 0-pentanitrates were crystallized from methanol-water, the first crystallization being o from solvents (at about 25 ) and subsequent recrystal­ lisations from warm methanol-water. The second recry­ stallization of ^-galactonamide pentanitrate was usually effected by using solvents at a temperature of 60-70°, whereas D—gluconamide pentanitrate was reerystallized from solvents at a slightly lower temperature, namely,

50—60°, Ethanol-water was also used for recrystallization of the nitrates but with less promising results.

It was very important that the freshly prepared crude aldonamide nitrate be carefully freed of all nitra­ ting solution and sodium fluoride by repeated washes with chloroform and water before drying the crude nitrate, as the presence of the contaminants adversely affected all attempts at subsequent crystallization of the nitrate*

Moreover, it was also very important that the crude nitrate be dried thoroughly under anhydrous conditions before attempting a crystallization of the material. It was found that a slightly moist aldonamide nitrate which con­ tained some sodium fluoride as a contaminant decomposed when an attempt was made to crystallize it from methanol- -62- water. A thoroughly dry crude nitrate which contained some sodium fluoride could, however, be crystallized successfully if the residual sodium fluoride was filtered from the anhydrous methanol before adding water to pre­ cipitate the nitrate. All attempts to crystallize the crude nitrates from hot solvents were unsuccessful.

However, subsequent recrystallizations could safely be carried out by using warm solvents. The melting point of the nitrate was found to vary by several degrees and depended on the solvent pair and conditions used in the recrystallization.

0. Preparation _of_ Aldonic Acid Pentanitrates Fischer and Warburg (100) had observed that, by the

(lOû) E. Fischer and 0, Warburg, Ann., 3A0. 171 (1905). action of nitrosyl halide on the amino acid, the amine group could be replaced directly by a halogen. It was, therefore, hoped that the reaction developed by Wolfrom and co-workers (69), viz., the action of nitrosyl halide on an 0—esterified aldonamide, might be applied to the nitrated aldonamides and give directly the nitrated aldonyl chlorides. The anticipated reaction might be formulated as follows. —63—

CONHo GOCl ‘ + HpO CHONO^t < HOAc CHONO- X d

In our case, the reaction COCl COOH « + EgO > * + HCl GHONO^ GHONG^ interfered, and our hope of obtaining directly the acid chloride was not fulfilled, the nitrated aldonic acid being the reaction product*

2,-Galactonic acid pentanitrate and ^-gluconic acid pentanitrate were prepared in yields greater than B0% by reacting gaseous nitrosyl chloride (in large excess) dissolved in glacial acetic acid with the corresponding nitrated aldonamides. In the course of repeat experi­ ments, it was found that the yield of the nitrated aldonic acid could be varied by changing the ratio by weight of nitrosyl chloride to nitrated aldonamide, jD-Gluconamide

0-pentanitrate (1 g,), when deaminated with nitrosyl chloride (25 g.), gave a yield of about 70% of nitrated aldonic acid. When the weight ratio of reactants was increased to 4-0:1, the yield of product was increased to 88^, It is to be recalled that the deamination of the nitrated aldonamide proceeded for about one day at an average temperature of about 20°. It is possible that by raising the temperature of deamination, the large excess of nitrosyl chloride might be reduced. —6 4“ Is connection with a study of isolation of the al­ donic acid pentanitrates by evaporation of the glacial acetic acid under reduced pressure, it was found that the temperature and degree of evaporation of the solvent were critical Ih determining yield and purity of product. This was especially so when attempting to remove the final traces of acetic acid; temperatures in excess of 30® hastened the decomposition of the crude aldonic acid nitrates. Moreover, it was found that the crude aldonic acid nitrate displayed a much greater degree of instability than the purified product. It was impera­ tive that the crude aldonic acid nitrate be crystallized immediately from anhydrous ether—light petroleum ether after evaporation of the solvent in order to prevent decomposition of the crude product,

E, Preparation of Methyl Aldonate Pentanitrates

1, Diazomethane

The diazomethane used in this work was prepared by the method of Arndt (79) employing potassium hydroxide upon nitrosomethylurea.

Precautions must be taken in the preparation and use of the diazomethane, Nitrosomethylurea is an unstable compound and must be kept at low temperature (0®), On standing at room temperature, it frequently decomposes with the evolution of heat and of irritating fumes* —6 5— Diazomethane itself is a very poisonous gas which at­ tacks the skin, eyes and lungs. Frequent exposure leads to super-sensitivity. In the pure liquid or gaseous state, diazomethane is also explosive. Thus, in the preparation cited, it was diluted with ether when in the gaseous state.

When small batches of aldonic acids were esterified, it was found that satisfactory results were obtained if the diazomethane—ether solution was decanted from the aqueous alkali reaction mixture and subsequently dried over potassium hydroxide pellets,

2, Preparation of Methyl D-Galactonate Penta-

nitrate and Methyl D-Gluconate Pentanitrate The methyl esters of the aldonic acid nitrates were prepared by reacting diazomethane in ether solution with the aldonic acid pentanltrates. It was found that the reactants, viz,, the diazomethane and the aldonic acid pentanitrate, must be present in mole-mole ratio. An excess of diazomethane apparently caused an unknown destructive effect on the esterified acid nitrate con­ sequently lowering the yield of the ester to about 5G^, as well as making the separation of the by-products of the reaction from the methyl ester of the aldonic acid nitrate very difficult. When excess diazomethane was used, the estérification reaction between the aldonic —66— acid pentanitrate and the diazomethane was instantaneous and was accompanied by the rapid evolution of nitrogen gas, whereas the subsequent reaction, namely, that be­ tween the esterified acid nitrate and the diazomethane, was much slower and produced by-products having an oily appearance (which we made no attempt to identify).

With proper control of mole-mole ratio of the re­ actants, the estérification of the aldonic acid nitrate was vory simple to perform and gave an almost quantita­ tive yield of the methyl ester nitrate. If the volume of ether was controlled as described in the experimental section, the methyl ester crystallized readily upon cool­ ing the ether solution. The addition of a sufficient quantity of light petroleum ether to the filtrate would readily cause the precipitation of a second crop of the methyl nitrate ester, A second recrystallization of methyl D-galactonate pentanitrate yielded beautiful, white crystals of constant melting point. As methyl D- gluconate pentanitrate was more soluble in ether than methyl ^-galactonate pentanitrate, a larger excess of petroleum ether (light) was needed to induce crystalli­ zation of the former than the latter ester,

F. Stability and Sensitivity of Nitrated Aldonic Acids and Their Derivatives

The stability of the nitrated aldonic acids and their -67- derivatives was determined with ethyl violet test paper»

A decoloration of the test paper, which was stored with the sample in a stoppered vial, indicated that the ni­ trate was decomposing. Sensitivity of each nitrate to heat was indicated by the fact that a small sample of nitrate exploded when heated gently (by a bunsen burner) in an open test tube. Similarly, each nitrate displayed sensitivity to percussion as a small amount of the nitrate, when placed on a metal surface (small vise) and struck with a hammer, produced a sharp report or ex­ plosion (Table I)*

As evidenced by the results shown in Table I, re- crystallized D-galactonamide 0-pentanitrate and D-glucon- amide 0—pentanitrate showed complete stability at temperatures up to 25° when stored for about one-half month. However, these nitrates underwent a very slight o decomposition at temperatures from 20-35 (room tempera­ ture during July and August), Of the two aforementioned

nitrated amides, 2,-galactonamide 0-pentanitrate was

the more stable at elevated temperatures. Judged by

odor and sight alone, both purified aldonamide nitrates

showed complete stability even after periods of storage

at 20-35° for at least six months.

Samples of crude ^-galaotonamide 0-pentanitrate and

D-gluconamide 0-pentanitrate have been stored at room

temperatures in closed vials (kept under atmospheric —68"" conditions) for more than one year. They were still white after this period of storage and displayed no visible nitrogen oxides but had a faint odor when the vials were opened. Judged by intensity of odor, crude D—glueonamide

0-pentanitrate was more unstable than crude 2.-galacton— amide 0—pentanitrate. Each of the crude amide nitrates decolorized (almost fully) test papers in about one month.

This test also corroborated the fact that D—glueonamide

0-pentanitrate was more unstable than D-galactonamide

0-pentanitrate*

It was found that the nitrated aldonic acids were relatively more unstable than the nitrated aldonamides.

As with the aldonamide nitrates, the D-glueose member was more unstable than the D-galactose derivative.

Samples of purified aldonic acid nitrates were stored for about nine months at temperatures from 20—35^ and displayed no evidence of nitrogen oxides. Judged by color only.

As the main purpose of this investigation was to prepare the methyl esters of nitrated aldonic acids and test their compatibility with cellulose nitrate, it was very disappointing to discover that the methyl nitrate esters were the most unstable of the various nitrates prepared. One might have expected that the methyl esters would be more stable than their parent compounds, namely, the nitrated aldonic acids. This instability might be -69- due to the fact that the diazomethane had a catalytic effect on the decomposition of the nitrate. Even at 0° the methyl esters of the nitrated aldonic acids showed a slight instability.

G. Comnatibility and Stability of Films of Aldonic

Acid Nitrate Derivatives and Cellulose Nitrate

Double—base films of each of the aldonic acid penta— nitrate derivatives and cellulose nitrate (in the ratio of 1:4 by weight) were made by dissolving the nitrates in ethyl acetate and subsequently evaporating the solvent.

A control film was made of similar cellulose nitrate only

(12.6^ nitrogen content). If the film made of the al­ donic acid nitrate derivative and cellulose nitrate was as clear as the control film (when viewed under a"micro­ scope). the two different nitrates were considered to be compatible with each other. The stability of each of the films was determined in a manner similar to that used in testing the stability of the nitrate itself.

The fact that each of the methyl pentanitrate aldonates and cellulose nitrate formed a clear film was strong evidence that the two were compatible under the condi­ tions previously noted (Table II). As was to be expected, the aforementioned films showed a stability to ethyl violet test paper similar to that shewn by the methyl ester alone, that is, the film was moderately stable at 0° and unstable at 20-35®* -70-

H, Action of Dlphenylamine on Double—Base Films

Diphènylamine is known to stabilize cellulose nitrate and it was hoped that it might have a similar effect on aldonamide nitrates and methyl nitrate esters of the aldonic acids (8S). Accordingly, another set of films was prepared in which diphenylamine (1% by weight of solids) was incorporated with the nitrates*

The similarity in appearance of each of the films pre­ pared by the incorporation of the nitrated aldonic acid derivatives, cellulose nitrate and diphenylamine, with the control film of cellulose nitrate and diphenyl­ amine only (Table III) was evidence that the three components were compatible*

The gradual development of a yellow color in the films was indication that some decomposition was taking place. The control film showed a faint yellow color after storage at 2G-35® for 30 days. It was interesting to note that all strips of test paper which were used to test the stability of the films which were stabilized with diphenylamine still retained some color after a 30 day period of testing at 20-35®. In contradistinction to this, strips of ethyl violet test paper were completely decolored in 5 days by films without any stabilizer and which were stored under the same conditions* -71-

V. ACKNOWLEDGMENTS

This work was supported mainly by the Ordnance

Department under contract (DA-33-019-ord-l63 and

DA-33-019-ord-ll; supervising agency. Ballistic

Research Laboratories, Aberdeen Proving Ground,

Maryland) with the Ohio State University Research

Foundation,

Mrs, E, Klotz (101), Mr. J. Kraus (lOl), and

(101) Microanalytical Lab., The Ohio State Uni­ versity, Columbus, Ohio,

Dr. Huffman (102) carried out the microanalyses of the

(102) Huffman Microanalytical Laboratories, 505 Majestic Bldg., Denver, 2, Colorado, nitra te s. -72-

71, SUMMARY

1, By the nitration of D-galactonamlde with

nitrogen pentoxide in ethanol-free chloroform and in

the presence of sodium fluoride, D-galactonamide

0-pentanitrate has been synthesized in crystalline

form,

2, D-Galactonic acid pentanitrate has been syn­

thesized in crystalline form by the deamination of

D-galactonamide 0-pentanitrate with nitrosyl chloride

in glacial acetic acid,

3, Crystalline methyl D-galactonate pentanitrate

has been prepared by the action of diazomethane in

ether on D-galactonic acid pentanitrate,

4, D-Gluconamide 0-pentanitrate has been syn­

thesized in crystalline form by the action of nitrogen

pentoxide on D-gluconamide,

5, D-Glueonic acid pentanitrate has been prepared

in crystalline form by deaminating D,—glueonamide 0-

pentanitrate with nitrosyl chloride in glacial acetic

acid, 6, The synthesis of methyl D-gluconate penta­

nitrate in crystalline form has been carried out by

the estérification of D—gluconic acid pentanitrate with

diazomethane in ether. -73-

7» The aforementioned aldonamide pentanitrates have been found to be relatively more stable than the previously mentioned aldonic acid pentanitrates and their corresponding methyl esters as determined by the action of each on test paper,

g. Each of the aforementioned nitrates has been found to be sensitive to heat and to percussion,

9, Each of the sugar nitrates, namely, ^-galacton­ amide 0-pentanitrate, 2,-glue onamide 0-pentanitrate, methyl D-galactonate pentanitrate, and methyl 2~ gluconate pentanitrate, has been found to be compatible with diphenylamine and cellulose nitrate having a nitrogen content of 12,6% as evidenced by the fact that the three components formed a clear film,

10, Films which contained no diphenylamine have been found to show a faster rate of decoloration of test paper than those in which the stabilizer was in­ corporated with the cellulose nitrate and each of the sugar nitrates. —74""

PART II

ATTEMPTED APPLICATION OF FULLY NITRATED ALDONIC

ACIDS IN SYNTHESES

I. OBJECTIVE

The main objective of this part of the research was to synthesize polyesters from the fully nitrated aldonic acids (described in Part I of this dissertation) and polyhydroxy alcohols. These polyesters were subsequent­ ly to be denitrated, yielding polysaccharide type of compounds.

As an O-esterified aldonic acid possesses one reactive carboxyl group, each molecule can be esteri­ fied with a hydroxy compound. If the reaction is between a dihydroxy alcohol and an 0-esterified aldonic acid, it is obvious that two molecules of the latter and one of the former would be involved in the intermolecular estérification. The reaction between a hexitol and an

0-esterified aldonic acid would lead to a complex molecule of quite high molecular weight. The term

"polyester" has been applied to the product of such reactions and can be simply illustrated by the reaction of ethylene glycol and an aldonyl chloride penta- acetate , -75-

COGl CH^OH COOCHoGHoOOC t I 2 2, (GHOAc) , CHgOH (GHOAc) (GHOAc), » 4 I 4 1 4 CHgOAc GHgOAc GHgOAc

COOCH^CH^OOG Î 2 2, (CHOH), (CHOH), f ^ ,4 CHgOH CHgOH

II

The resulting polyester (l), if it could then be deacetylated, would lead to an interesting type of compound (II) similar in many respects to a di- saccharide. —7 6~

II. HISTORICAL

A. Polyesters

The two known methods of preparing carbohydrate

polyesters are by;

(a) Estérification of an 0—esterified aldonyl chloride

with a monohydroxy or polyhydroxy alcohol*

(b) Direct estérification of an aldonic acid or lac­

tone with an alcohol.

The preparation of ethyl JD-glnconate pentaacetate

from D-gluconyl chloride pentaacetate and absolute al­

cohol is one of the first examples in which an 0-esteri­

fied sugar acid chloride was esterified with an alcohol

(6 3 ), Wolfrom and Morgan (67) made application of fully

acetylated D—gluconyl chloride in their preparation of

complex polyesters of polyhydroxy alcohols. They found

that an excess of D-gluconyl chloride pentaacetate was

necessary in order to prepare the polyesters of glycerol

and of various hexitols. It is interesting to note

that Hicoud (103), in her study of the estérification

(1 0 3) Mlle. G. Nicoud, J* des Recherches du Centre National de la Recherche Scientifique, 286 (1949)*

of D-mannitol by lauroyl chloride, found a similar re­

sult; that is, s large excess of lauroyl chloride was

required in order to prepare the hexalaurate of -77- D-mannitol. She stated that the steric hindrance was greatest at the time of the estérification of the last free hydroxyl group. Pyridine, which is often used as a catalyst for the estérification, forms initially a complex with the acid chloride, and this complex sub­ sequently reacts with the alcohol (67, 103). Goldsmith

(104-), in his discussion of the reaction of polyhydric

(104.) H. A. Goldsmith, Chem. Revs., 21, 257 (1943). alcohols with fatty acid halides, has summarized many pertinent facts in this field.

There is little information on the direst estéri­ fication of aldonic or glycario acids by alcohols in the presence of a catalyst. Major and Cook (105) pre-

(105) R. T. Major and E. W. Cook, J. Am. Chem. Soc., 2474 (1936). pared ethyl D-gluconate pentaacetate by reacting D- gluconic acid pentaacetate with absolute alcohol in the presence of 2% hydrogen chloride. Thielepape (106)

(106) E. Thielepape, Ber., 66 B . 1454 (1933), used ^-toluenesulfonic acid as a catalyst for the direct estérification of D—tartaric acid with absolute ethanol.

The reaction was very slow and required refluxing as well as the inclusion of calcium carbide (contained in the - 78- thimble of a Soxhlet extractor) for absorbing water.

An investigation of the use of acid-regenerated cation exchangers as catalysts for estérification began as early as 194-1. German workers reported the use of

Wofatit as a catalyst for estérification (107), Sussman

(107) Dierichs, Report PB866, Office of Technical Services, Dept, of Commerce, Washington, 1945; cf. S. Sussman, Ind. and Eng, Chem., 1228 (1946).

(107) used Zeo—Karb H (a sulfonated coal type of cation exchanger) as a catalyst for estérification of acetic acid with glycerol or ethylene glycol. Recently, Smith and co-workers (108) and Osman and associates (109) made

(108) J. E. Gadotte, F. Smith and D, Spriestersbach, J, Am. Chem. Soc., 2Â, 1501 (1952). (109) E, M. Osman, K. C, Hobbs and W. E, Walston, Abstracts Papers Am. Chem. Soc., 118, 3R (1950); J. Am. Chem, Soc., 22, 2726 (1951). an interesting discovery in which ion exchange resins

successfully catalyzed the reaction of D-galacturonic acid with methanol to form the methyl ester of methyl

(methyl oC-D-galactopyranosid)—uronate. -79-

III. EXPERIMENTAL

A. Preparation of ^-Galactonyl Chloride

Pentanitrate

1» Using Phosphorus Pentachloride

D-Galactonyl chloride pentanitrate was synthesized

from D-galactonic acid pentanitrate and phosphorus

pentachloride by a modification of the procedure utilized

by Major and Cook (63).

To a solution of 0,2 g. of anhydrous ^-galactonic

acid pentanitrate in 2 ml. of anhydrous ether was added

0,1 g, of phosphorus pentachloride. The mixture was

shaken mechanically until a clear solution was effected

and then left stand at 0° for one hour. Crystallization

of the acid chloride was induced by the slow addition

of anhydrous petroleum ether (35—50°) until incipient

turbidity. The mixture was kept at 0° overnight to

ensure complete crystallization. The supernatant liquors

were decanted from the crystals as carefully and com­

pletely as possible and the residual crystals were washed o by décantation with light petroleum ether; m,p, 75-95

(dec., cor,), A second recrystallization of the product

was effected from the same solvent pair; m.p, compound

began to turn brown at about 115°*

To a solution of £-galactonyl chloride pentanitrate

in alcohol, a few drops of a 10% solution of silver —80— nitrate were added, A white precipitate (presumably silver chloride) was immediately formed.

A small sample of D-galactonyl chloride penta­ nitrate was placed in a dry 3 ml, stoppered vial con­ taining a piece of moistened blue litmus paper (the test paper was kept above the sample of nitrate). The test paper turned red in a period of time of about 2 minutes, A sample of the acid chloride, when left ex­ posed to the air for several hours, decomposed with the formation of D—galactonic acid pentanitrate; m.p, 130-

133°, £—Galactonyl chloride pentanitrate was too un­ stable for exact characterization and analyses,

2, Using Thionvl Chloride

An attempt was made to prepare D-galactonyl chloride pentanitrate using thionyl chloride, instead of phos­ phorus pentachloride, as the chlorinating agent of the nitrated aldonic acid. The reaction mixture turned yellow in color. Attempts to crystallize the gummy material formed in the reaction were unsuccessful*

B. Attempted Preparation of Ethylene Glycol

Di—£—Galactonate Pentanitrate

1* Using pyridine as Catalyst

An attempt was made to prepare ethylene glycol di-D-galactonate pentanitrate from D-galactonyl chloride pentanitrate and ethylene glycol according to the method —81— used by Wolfrom and Morgan (67).

£-Galactonyl chloride pentanitrate (prepared from

0,2 g. of D-galactonic acid pentanitrate) was dissolved in anhydrous dioxane (4 ml,). To the resulting solu­ tion, anhydrous ethylene glycol (0,01 ml.) and anhydrous pyridine (0,03 ml,) were added and the mixture was then shaken mechanically for one hour. There was a rapid reaction and a precipitate formed rapidly. After the mixture was allowed to stand overnight at 0°, the crystalline solid was filtered and washed with cold dioxane followed by ether; yield, 0,05 g., m.p, 105- lOS® (dec,, cOr.). The compound was faint yellow in color. It was recrystallized from ethanol-free chloroform- light petroleum ether; m.p, 106-107°. The compound appeared to soften at about 95°. When deft exposed to moist air, the crystals gradually softened and finally changed to an oil.

The crystalline complex was insoluble in ether, light petroleum ether, dioxane, slightly soluble in chloroform and very soluble in methanol. When heated in a test tube, the compound decomposed with evolution of brown fumes but it did not explode,

2, Using Excess Pyridine and Ether as a Diluent

D-Galactonyl chloride pentanitrate (about 0.03 g.) in 1 ml, anhydrous ether), ethylene glycol (0,05 ml,). -S2-. and anhydrous pyridine (0,5 ml.) were occasionally

shaken and kept at 30° for 3 hours and then left at

0° for 20 hours. The solution, yellow in color, was added to excess water and left stand at 0° for several days. No precipitate was formed.

3. Using Excess Pyridine

D-Galactonyl chloride pentanitrate (about 0.05 g«) and ethylene glycol (0,2 ml.) were added to anhydrous pyridine (l ml.). The reactants, which became warm after the addition of pyridine, were kept at room temperature for 2 hours and then at 0° for 20 hours. The solution, yellow in color, was then poured into water (50 ml,) and left stand at 0° for several days. No precipitate was formed,

4» Using n—Tributvlamine as Catalyst

An attempt was made to esterify D—galactonyl chloride pentanitrate, dissolved in dioxane, with ethylene glycol

in the presence of sodium—dried n-tributylamine. After

the amine was added, the solution began to fume and it became highly colored. As a result, the reaction mix­

ture was discarded. In a repeat reaction, but without

ethylene glycol, similar results were obtained,

5, Using Nalcite HCR (Resin) as Catalyst

An unsuccessful attempt was made to esterify D— galactonyl chloride pentanitrate with anhydrous methanol —83—

in the presence of Nalcite HCR,

6. Using No Catalyst and Dioxane as Solvent

D—Galactonyl chloride pentanitrate (prepared from 0.11 g, of D-galactonic acid pentanitrate) and anhydrous ethylene glycol (0,006 ml.) were dissolved in anhydrous

dioxane (1 ml,). The clear solution was left stand at room temperature for 4 days and then distilled under reduced pressure. The residue was dissolved in anhydrous

ether and crystallization induced by the slow addition

of light petroleum ether. The crystalline compound was

acidic; m.p, 130-133°. The melting point of D-galac-

tonic acid pentanitrate is 137®,

7. Using No Bnsic Catalyst and Glacial

Acetic Acid as Solvent

An unsuccessful attempt was made to esterify &-

galactonyl chloride pentanitrate with ethylene glycol

in the presence of glacial acetic acid. The reaction was run as described in the preceding section (see

Section B, 6). An acidic compound, melting at 130-

133®, was recovered*

8. Using Silver. Carbonate

D-Galactonic acid pentanitrate (0,15 g.) was dis­

solved in anhydrous ether (4 ml,). Phosphorus penta­

chloride (0,08 g.) was added to the solution and the

mixture agitated until a clear solution was effected. •"84.“* After the solution was left stand at room temperature for one hour, anhydrous methanol (0.5 ml.) was added.

Four portions of dry silver carbonate (each 0.2 g.) were added during a period of time of 10 hours and stirring was maintained continuously throughout this period of time. Evolution of gas took place when silver carbonate was first added.

The silver carbonate was filtered and to the fil­ trate, hydrogen sulfide was added in order to precipitate silver ion. After the first crop of silver sulfide was filtered, the filtrate was again treated with hydrogen sulfide. The clear filtrate was evaporated v acuo leaving a viscous sirup which was soluble in absolute ether. To the ether solution, anhydrous light petroleum ether was added until incipient turbidity. The solution was left stand at 0® for several days but no precipitate was formed.

C, Attempted Direct Estérification of D-Galactonic

Acid Pentanityate with Methanol

1. Using Dowex 50 as Catalyst

An attempt was made to prepare methyl ^-galactonate pentanitrate by direct estérification of D-galactonic acid pentanitrate with methanol in the presence of Dowex

50, according to the method of Smith and co-workers (107),

To a solution of D-galactonic acid pentanitrate

(0.2 g.) in anhydrous methanol (20 ml,), freshly acid- -85-

regenerated Dowex 50 (0.4 g.) was added. After the mixture was shaken mechanically for 11 hours at room

temperature, it was filtered and the resin washed with

several portions of methanol. Evaporation of the fil­

trate under vacuum yielded a crystalline product having

a melting point almost identical to that of D-galactonic

acid pentanitrate.

An unsuccessful attempt was made to carry out the direct estérification of D-galactonic acid pentanitrate with methanol in the presence of Dowex 50 at a reaction

temperature of 60=70° for 10 hours. Under these condi­

tions, the nitrated aldonic acid underwent decomposition,

2, Using ^-Toluene Sulfonic Acid as Catalyst An unsuccessful attempt was made to esterify directly

D-galactonic acid pentanitrate (0,12 g,) with methanol

(5 ml.) in the presence of .g-toluene sulfonic acid (0.005

g.) as catalyst. The reaction was allowed to proceed for

6 hours at 50-70°. The methanol was distilled under re­

duced pressure at room temperature, leaving a small

amount of a yellowish colored oily residue. This residue

could not be recrystallized from ether-light petroleum

ether and was abandoned. ••86"-

IV« DISCUSSION

A, Preparation of fi-Galactonyl Chloride Pentanitrate

D-Galactonyl chloride pentanitrate was prepared

from Ê—galactonic acid pentanitrate and phosphorus penta­

chloride by a modification of the procedure used by

Major and Cook (63). The acid chloride was formed read­

ily, but attempts to isolate and characterize it were

unsuccessful since it decomposed very rapidly in the air

with the evolution of hydrogen chloride and with the

formation of D-galactonic acid pentanitrate.

Attempts to use thionyl chloride instead of phos­

phorus pentachloride as the chlorinating agent were

unsuccessful. There was evidence of decomposition of

the product or starting material as the reaction mixture

became highly colored,

B, Attempted Preparation of Ethylene Glvcol

Pi—D-Galactonate Pentanitrate An unsuccessful attempt was made to prepare ethylene

glycol di-D.-galactonate pentanitrate by esterifying

B-galactonyl chloride pentanitrate with ethylene glycol

in the presence of pyridine according to the method used

by Wolfrom and Morgan (67), It is a known fact that

many acid chlorides form complexes with pyridine (67, 103),

but it was hoped that the complex formed in our work would

react further with the ethylene glycol. Under the conditions “SV" used, this second reaction did not take place. It is possible that at more elevated temperatures, the desired reaction would occur, but there is the danger of partial denitration with pyridine. It is interesting to note that the complex was crystalline and showed properties distinctly different from those possessed by D-galactonyl chloride pentanitrate or D—galactonic acid pentanitrate.

In the first place, the complex did not explode when heated but evolved brown fumes, whereas the free acid exploded when heated. Secondly, the complex was a colored

(light yellow) compound which liquefied slowly when left exposed to the moist air.

Attempts to esterify directly ^-galactonyl chloride pentanitrate with ethylene glycol in the presence of a solvent without a catalyst were unsuccessful as D- galactonic acid pentanitrate was recovered from the reaction mixture. The hydrolysis of the acid chloride might have taken place either during the reaction or during the isolation of the product (a trace of mois­ ture would be sufficient to cause such hydrolysis).

When a—tributylamine was used as a catalyst for the estérification of D-galactonyl chloride pentanitrate and ethylene glycol, the reactants began to fume and became highly colored. As it was believed that the starting material was sensitive to the strong base, the reaction «•88*" was abandoned. It is possible that a highly sterically hindered amine (which is a weak base) might be unable to react with the acid chloride and yet react with the anticipated by-product of the reaction, namely, hydrogen chloride.

C, Attempted Direct Estérification of D-Galae-

tonic Acid Pentanitrate with Methanol

1, Using Dowex 50 (Resin) as Catalyst

An unsuccessful attempt was made to prepare methyl

D-galactonate pentanitrate by direct estérification of

D-galactonic acid pentanitrate with methanol in the presence of a sulfonic acid resin, Dowex 50, according to the procedure of Smith and co—workers (108), When the reaction was carried out at room temperature, the starting material (D—galactonic acid pentanitrate) was recovered unchanged, but at a temperature of 60-70° it decomposed,

2, Using E-Toluene Sulfonic Acid as Catalyst

The attempt to esterify directly D-galactonic acid pentanitrate with methanol in the presence of E-toluene sulfonic acid at a temperature of 50-70° was unsuccessful, —89—

V. SUMMARY

1, Crystalline D-galactonyl chloride pentanitrate was prepared by the action of phosphorus pentachloride on D-galactonic acid pentanitrate in ether*

2, By the reaction of D-galactonyl chloride penta­ nitrate in dioxane with pyridine a crystalline complex was synthesized,

3, Attempts to esterify D-galactonyl chloride pentanitrate dissolved in doxane with ethylene glycol in the presence of pyridine led to the formation of a crystalline complex of pyridine and the sugar nitrate but no polyester was formed,

4, D-Galactonic acid pentanitrate was not directly esterified with methanol in the presence of Dowex 50 as catalyst. When estarification was carried out at room temperature, the starting material was recovered but at 60-?0*^ the nitrated aldonic acid was found to decompose,

5, The direct estérification of D-galactonic acid pentanitrate with methanol in the presence of ^-toluene sulfonic acid as catalyst produced a small yield of an oily residue which could not be crystallized. -90-

PART III

PREPARATION OF PENTABENZTL D-GLUCONIC ACID AND ITS PROPOSED USE IN SYNTHESES

I. OBJECTIVE

The objectives of this part of the research were twofold: first, to synthesize pentabenzyl-D-gluconic acid and second, to utilize the benzylated sugar acid in the syntheses of disaccharide and polysaccharide type of compounds.

It is to be recalled that one of the main objec­ tives of the research as outlined in Part I was the syntheses of nitrated aldonic acids. Following the successful conclusion of this work, the utilization of the nitrated aldonic acid in the syntheses of polyesters proved unfeasible because of the fact that the nitrated aldonyl chloride (obtained from the nitrated aldonic acid) was found to be very reactive and decomposed read­ ily (possibly due to the great activating effect of the nitrate groups). This work was outlined in Part II,

Therefore, it was desirable to use a blocking group of the hydroxyls of the aldonic acid with lesser activating effect than the nitrate group but which would be stable and could subsequently be removed. These requirements are met by the benzyl ether group. As a result, our next objective was the synthesis of a fully benzylated —91— D-gluconic acid.

Theoretically, this objective might be attained in any one of the following three ways;

(a) Conversion of D-glucono- s-lactone (l) into D- gluconamide (II), and transformation of the latter into

O-benzylated D-gluconamide (III), followed by deamina­ tion to produce the fully benzylated D-gluconic acid (IV),

These transformations are shown by the following reaction sequence, wherein E = G^H^GHg-.

0 II C ------CONHg COÏÏH2 COgB I (CHOH)- ^ (GHOH) . ^ (GHOR), ^ (GHOR). t ! 4 Î 4 HO------1 CH^OH GHgOa GB^OR I CEgOH

II III IV

(b) Direct replacement of acetyl groups of D-gluconic acid pentaacetate (I) with benzyl groups to yield penta- benzyl-D-gluconic acid (II), This is shown by the following equation,

GOoH CO«H I t (GHOAc)^ --- ^ (GHOR)^

GH2 OAC GEgOR I II

(c) utilisation of an aldose (I) as a starting material, followed by blocking of hemiacetal formation by conversion -92- to D-glucose diethyl mercaptal (ll), Bgnzylation of the latter would produce peata-O-benzyl-D-glucose di­ ethyl mercaptal (III), and this, when demercaptalated, would yield neata-O-benzyl-aldeh-ydo-D-glucose (IV)*

The benzylated aldose could then be oxidized to penta- benzyl-D-gluconic acid (V), These reactions are shown by the following reaction sequence*

HC=0 HC(SEt)g HG(3Et)2 HG=0 CO_H I t . I 1 I 2 (CHOH), V (CHOH). __ . (GHOR). __ . (GHOR), . (GHOR) I 4- I ** ' I 4- Z I 4 7 , i CH^OH GHgOH GHgOR CH^OR GH^OR

I II III IV V

The second objective of this research was to be attained by esterifying the acid chloride of pentabenzyl-

2-gluconic acid with a polyhydroxy alcohol to yield a penta-0-benzyl-D-gluconate of the polyhydroxy alcohol (l)*

Catalytic hydrogenolysis of I might be expected to produce a polysaccharide type of compound (II), which, in the case of the hexitol derivative (C]^Q2^134^72)) would have a molecular weight of 2 512* -93- These reactions, using a hexitol as an example of the

polyhydroxy alcohol, are shown below.

COgH. GOCl ' CH5OH CH20CO(OHOR)^CH20R t I ^ (CHOR)^ (CHOH), (CHOH), CHOCO(GHOR)/GH„0R), I ^<44 OHgOa CHgOR GHgOH CH20G0(CH0R)^GH20R

I

GHgOGO(GHOH^CHgOH

(CHOCO(GH0H)^CH20H)^

GH2 OGO(CHOH)^GH20H

II — 94— II. HISTORICAL

A. Benzvl Ethers of Carbohydrates

The benzyl ethers of carbohydrates have not been extensively investigated since their discovery which took place about three decades ago. To the best know­ ledge of the author, there is no mention in the chemical literature of a fully O-benzylated hexose. This omission may be due to the great difficulty in attempting to prepare crystalline fully benzylated ether derivatives of carbohydrates•

The benzyl ether sugar derivatives have the great advantage of being stable to alkalies and acids and are easily hydrogenolyzed using platinum as a catalyst (llO)*

(110) K. Freudenberg, W. Dûrr and H, von Hoch- stetter, Ber., 1739 (1928)j German Patents 407,437 (1923) and 417,926 (1924).

Gomberg and co—workers (111) obtained a mixture of

(111) M, Gomberg and C. C, Buchler, J, Am. Ghem, Soc., 1904 (1921). benzyl ethers by reacting methyl®C-£-glucopyranoside with benzyl chloride in the presence of aqueous sodium hydrox­ ide. The oily mixture consisted largely of methyl di-0- benzyl- <<-^-glucopyranoside with some higher benzylated products. A method more extensively used, which was de­ veloped by Freudenberg and co-workers (112), consists of •95-

(112) K, Freudenberg, H. von Hochstetter and H. Engels, Ber., 666 (1925). first preparing, in ether, the sodium alkoxide of the sugar and subsequently reacting the latter with benzyl halide. In this way, the latter mentioned authors pre­ pared 3—O-benzyl-1,2t5,6-diisopropylidene-D-glucose in an oily state. In an extension of their work (113), they

(113) K, Freudenberg, ¥. Diirr and H, von Hoch­ stetter, Ber.., 1935 (1928), also used dioxane as a solvent, Schmid and associates

(114) showed that the liquid ammonia technique of Kraus;

(1 14) L, Schmid and B. Becker, Ber,, 1966 (1925). and White (115) could be used to prepare sodium derivatives

(115) C. A. Kraus and G. F. White, J, Am. Chem, Soc,, Ai, 769 (1923). of carbohydrates. Muskat (II6 ) made the sodium, potassium

(116) I, E. Muskat, J, Am. Chem. Soc., 693, 2449 (1934); S. Soltzberg, Ü. S, Patent 2,234,200 (March 11, 1938). and lithium derivatives of sugars. The alkali alkoxide, when reacted with an arylating agent, yielded aryl sugar ethers. Muskat originally suggested that éthérification —96— could be completed in the presence of liquid ammonia, but in later work stated that it was advisable to remove the ammonia before adding a halide. This is obviously true, as the desired product would otherwise be contami­ nated with amines. The great insolubility of the alkali alkoxides in liquid ammonia necessitates that éthérifi­ cation be repeated until the required degree of substitu­ tion has been attained.

An interesting finding was obtained by Zemplen and co-workers (117) who demonstrated that sugar acetates,

(117) G. Zemplen, Z , CsiirBs and S. Angyal, Ber,, 70 B . 1848 (1937), when reacted with benzyl chloride and powdered potassium hydroxide, underwent deacetylation and benzylation.

Using this method they prepared tribenzyl-D-glucosan,

The applicability of this method to the preparation of other sugar benzyl ethers was shown by Bell and co­ workers (118) who prepared methyl 2 ,3-di-O-benzyl- a -£-

(118) J, S. D. Bacon, D. J. Bell and J, Lorber, J. Chem. Soc,. 453 (1940)j D. J, Bell and J. Lorber, ibid.. 1147 (1940). glucopyranoside and methyl 2,3-di-O—benzyl-4,6-benzyli- dene-a-D-galactopyranoside, each in crystalline condition, from the corresponding diacetyl sugar derivatives, Adams, -97-

Reeves and Goebel (119) also found that better yields of

(119) M. H, Adams, R. E. Reeves and W. F. Goebel^ J. Biol. Chem., lAO. 653 (1941).

3-0-benzyl-l,2: 5,6—diisopropylidene-D-glueose could be obtained by reacting the corresponding monoacetyl deri­ vative with benzyl chloride and potassium hydroxide than by using 1,2 :5,6-.diisopropylidene-B-glueose alone. Hudson and co-workers (120) have also used the Zemplen procedure

(120) R. M, Hann, W. T. Haskins and C. S. Hudson, J. Am. Chem. Soc., 986 (1942). with success in preparing dibenzyl derivatives of polyols.

Sowden and Fischer (121) made application of the

(121) J. C. Sowden and H. 0. L, Fischer, J. Am. Chem. Soc., 3244 (1941). sodium naphthalene reagent (122) in their preparation of

(122) H. D. Scott, J. T. walker and V. L, Hansley, J. Am. Chem. See., 2442 (1936); J. T. Walker and N, D. Scott, ibid.. 6a, 951 (5-938). a mono-benzyl ether derivative of glycerol.

B«. Sugar Mercantals

The first successful preparation of a sugar mercaptal was done by Fischer (123). He reacted the aldose with -9S-

(123) E. Fischer, Ber., 2Z, 673 (1894). ethyl mercaptan in the presence of concentrated hydrochloric acid. This reaction may be represented by the following equation,

HG=0 C.H.SH HC(SC_H_). — > ’ ^ + EpO HC-OH ^ HCOH 2

It is to be noted that two thioalkyl groups are intro­ duced to produce a mercaptal. The mercaptals are easily prepared and are stable to bases. Levene and Meyer (124)

(124) P. A, Levene and G. M, Meyer, J, Biol. Chem., 62, 175 (1926). made application of sugar mercaptals in their preparation of 0-pentamethyl D-glucose diethyl mercaptal (in oily state) from D-glucose diethyl mercaptal and dimethyl sulfate and sodium hydroxide. They then demercaptalated their derivative with mercuric chloride, yielding the first known open-chain sugar, namely, 0-pentamethyl- aldehvdo-D-glucose. Demercaptalation of sugars, first developed by Emil Fischer, was improved by Wolfrom and

co-workers (125,69), This method developed by the latter

(125) M, L , Wolfrom, J. Am, Chem. Soc,, 51. 2188 (1929), authors was a hydrolysis of the ethyl mercaptal in dilute -99- acotone solution by reaction with mercuric chloride in the presence of cadmium carbonate. This reaction may be represented by the following equation,

SE t HC — SEt ^ OHO + 2GlHgSEt + GdC]^ + COg ‘ ZHgClg+HgO

Brigl (126) and Wolfrom (127) demonstrated the wide

(126) P. Brigl and R, Schinle, Ber., 66, 325 (1933).

(127) M, L, Wolfrom, D . Weisblat and A, Hanze, J, Am, Ghem, Soc., 324-6 (1940). applicability of the sugar mercaptals as intermediates in the preparation of open-chain (aldehyde and keto) derivatives of sugars. —100™

III. EXPERIMENTAL

A,. Attempted Complete Benzylation of D-Gluconamide

1, First Benzylation of 0-Potassium Alkoxide

of D-Glnconamlde with Benzyl Chloride in

the Presence of Liquid Ammonia

The partial 0-potassium alkoxide of D-gluconamide

was prepared according to the method of Muskat (116) with

the improvement of Wolfrom and co-workers (128),

(128) M, L. Wolfrom, W. W. Binkley, W. L. Shilling and H. ¥. Hilton, J, Am. Chem. Soc., 21, 3553 (1951).

In a dry 1—liter three-necked round—bottomed flask,

equipped with a specially constructed cup for holding

potassium, was placed about 700 ml. of liquid ammonia.

A small pellet of clean potassium was added to the liquid

ammonia and if the solution remained blue in color, the

flask and contents were considered to be sufficiently

clean and dry. An amount of 14 grams of dry D—gluconamide

was dissolved in the solvent. Small pieces of potassium

were placed in the cup and liquid ammonia allowed to flow

over them in order to dissolve the metal and prevent it

from being coated with the sugar. 'Pellets, of potassium (6 g.) were dissolved until the characteristic blue color

remained. When the volume of liquid ammonia had diminished to

about 100 ml., freshly fractionated benzyl chloride -101-

(110 ml.) was added and the mixture stirred mechanically at room temperature for about ten hours. The ammonia was allowed to escape through a narrow orifice. Sodium-dried toluene (125 ml,) was added and the mixture heated at

80-90° by means of a water bath until the reaction was complete (a test sample diluted with water gave a neutral indicator paper test)»

The solids were filtered on a sintered glass funnel and washed with hot dixane (the solids contained some benzylated compound). Evaporation of the filtrate under reduced pressure yielded a light brownish oily material,

2, First Rebenzvlation of Partially Benzylated

D-Gluconamide with Benzyl Chloride in the Presence of Liquid Ammonia

The crude partially benzylated D-gluconamide was added to liquid ammonia (about 1 liter) and subsequently treated with pellets of potassium (about 7 g,) followed by benzyl chloride (100 ml,) in the same manner as used in the first benzylation. The crude product was a brown viscous oil. It was soluble in acetone and insoluble in water,

3. Second Rebenzvlation of Partially Benzylated

D-Gluconamide with Benzyl Chloride

Crude partially benzylated D-gluconamide (28 g.) was suspended in anhydrous ether (200 ml,). To the 102 — suspension liquid ammonia (600 ml.) was added and the mixture then treated with potassium (about 5 g.) until the blue eolor remained. After the ammonia was allowed to evaporate, the ether was distilled under reduced pressure. Anhydrous toluene (50 ml.) and benzyl chloride

(60 ml.) were added and the reaction mixture was left at room temperature until the heat of the reaction had subsided. The reaction mixture was heated at 80—90® until the reaction was complete.

After the reaction mixture was filtered, the solids were washed with dioxane and benzene. Evaporation of the filtrate under reduced pressure yielded a brownish oily material. This material was dissolved in a minimum of hot absolute alcohol and the solution left at room temperature for several hours and than at 0® for a day.

The major portion of the oil crystallized. The crystal­ line product was recrystallized from alcohol, m.p. 90-

92®; a 0.1908 g. sample in A,3360 g. of benzene depressed the freezing point by 0.81®. The molecular weight was found to be 278. These physical constants correspond very closely to those of tribenzyl amine.

The major portion of the benzylamines was removed by fractional crystallization from alcohol and the re­ maining oily material then subjected to steam distillation until the distillate was clear. The oily material was extracted with several portions of ether; the ether -103- extracts were then washed with water, dried and decolor­ ized, Evaporation of the solvent under reduced pressure left a viscous brown oil; yield 4 g.

I)-eJie..ralnaMon_ojf ■j^oA-eojalar Æeight of Partially

Benzylated 2,-Gluconamide 0.1506 g. of partially benzylated D-gluconamide dis­ solved in 4«28S3 g . of benzene depressed the freezing point 0.49°. The molecular weight of the benzylated compound was 367. The calculated molecular weight of

0-dibenzyl D-gluconamide is 375»

B. Attempted Benzylation of D—Gluconamide with

Sodium Naphthalene Reagent and Benzvl Bromide

An attempt was made to benzylate D-gluconamide by first preparing the sodium alkoxide of D-gluconamide with sodium naphthalene reagent and then benzylating the latter with benzyl bromide according to the method of

Sowden and Fischer (121).

1. Preparation of Sodium Naphthalene Reagent

Sodium naphthalene reagent was prepared according to the procedure of Scott and co-workers (122).

In a 250 ml. 3-neck flask, fitted with a mercury- seal stirrer and cooling bath, a steady stream of dry nitrogen was passed. A solution of naphthalene (11 g.) and etheylene glycol dimethyl ether (S3 g.) was placed in the flask and cooled to —10° (the ethylene glycol —104-” dimethyl ether was fractionated and dried over sodium)►

To the solution, which was stirred, clean sodium (0.5 g.) was added and the reaction allowed to proceed until the sodium had dissolved. Further pieces of sodium (a total amount of 3 g,) were added and the temperature of the bath allowed to rise slowly to about 25°. The solu­ tion (dark greenish black) was maintained at room tem­ perature and stirred for two hours,

2, Attempted Benzylation of D-Gluconamide with Sodium Manhthalene Reagent

An attempt was made to benzylate D-gluconamide with sodium naphthalene reagent according to the method of

Sowden and Fischer (119).

D—Gluconamide (4., 95 g. ) was added to the sodium naphthalene reagent described above, and the reactants maintained at room temperature for 24 hours. As the reaction was not complete after that time, the solvent was gently refluxed for another 3 hours (some unreacted sodium naphthalene reagent still remained in solution after this refluxing), After the reaction mixture was cooled, benzyl bromide (about 015 ml,) was added, A very vigorous reaction took place when the first quantity of benzyl bromide was added and the color of the solution became lighter. Further amounts of benzyl bromide were added until the total amount was 50 g. The reactants -10 5- were gently refluxed for about 30 hours. Evaporation of the solvent under reduced pressure and temperature not o exceeding 90 left a tarry black residue. This residue was insoluble in most organic solvents and in water, and was discarded,

C, Preparation of D-Gluconic Acid Pentaacetate D-Gluconic acid pentaacetate was prepared according to the method of Major and Cook (105).

D-Glucono-5—lactone was acetylated with acetic an­ hydride and freshly fused zinc chloride to yield D-gluconic acid-2,3,4,6-tetraacetate monohydrate. The latter was further acetylated with the same reagents to produce

D-gluconic acid pentaacetate monohydrate. Removal of water from the latter was effected by azeotroping with boiling toluene.

D. Attempted Preparation of Penta-O-benzyl—D— Gluconic Acid 1, Using Benzvl Bromide as Benzvlating Agent

An attempt was made to prepare penta-O-benzyl-^- gluconic acid according to a modification of the pro­ cedure developed by Zemplen and co-workers (117,120).

D-Gluconic acid pentaacetate (7 g.) was added to a solution of anhydrous toluene (75 ml.) and benzyl bromide (100 g.) contained in a flask protected from moisture and equipped with a mercury-seal stirrer and •»106~ reflux condenser,. To the resulting solution, heated at

90=100°, powdered potassium hydroxide (110 g,) was added in batches of about 40 g. during an interval of time of

3 hours. The reaction mixture was rapidly stirred and maintained at a temperature of about 90° for 6 hours and then left overnight at room ;temperature. The solid residue was filtered, crushed and washed with a minimum of light petroleum ether to removed residual benzyl bro­ mide. A minimum of water was added to dissolve all solids and to the resulting solution hydrochloric acid was eided until a pH of almost 9 was reached. The basic solution was now extracted with a minimum of ether (to remove more residual benzyl bromide) and then neutralized with hydrochloric acid. The reaction mixture was steam distilled until free of all steam-volatile substancesj yield 3 g. Concentrated hydrochloric acid was added

(until a pH of 2-3 was attained) and the precipitated oil was removed by extraction with two portions of ether

(total of 600 ml.). After the combined ether extracts were washed with water, they were partially decolorized with Barco G-60, filtered and dried with Drlerite. Sol­ vent removal under reduced pressure, after filtration, left a brown oily residue. Attempted fractionation of o this material at <1 mm. and 130 was discontinued as the boiling point of the compound was apparently above this temperature, and it was feared that the benzylated -107- acid might decompose. The oily material was dissolved in a minimum of boiling light petroleum ether and the solution left stand at room temperature for several hours and then at -10° for several days. A light brown oily residue precipitated. It was very soluble in chloroform, ether and slightly soluble in light petroleum ether, n—hexane, ^-heptane, and methanol, and insoluble in water. An amount of 0.0286 g. of the oily substance was dissolved in absolute ether (25 ml,). To this solu­ tion, distilled water (10 ml.) was added. The mixture was titrated with standard sodium hydroxide using phenolphthalein as an indicator. The titration was very slow and required about a week. Titration from methanol— water with standard sodium hydroxide was also very slow.

The sodium salts formed gels in either methanol-water or ether—water.

Anal. Calcd, for C^H^Oy(C^H^CH2 )5 : Molecular weight, 647, Found: by titration from ether-water, 680,

2, Chromatography of Benzylated D-Glueonic Acid

An amount of 0.185 g. of benzylated D-gluconic acid was dissolved in 4 cc. of chloroform (containing 0,75^ by volume ethanol) and the solution added at the top of a 220 X 34 mm. (in diam,) column (129) of a mixture of

(1 2 9) Column dimensions refer to the adsorbent. —108—

Magnesol (130/Celite (5:1 by weight). The chromatogram

(130) A synthetic, hydrated magneslnm acid silicate manufactured by the.Westvaco Chlorine Products Corp., South Charleston, West Virginia. Only Magnesol passing a 200-mesh screen and Celite passing an 80-mesh screen were employed, was developed with chloroform (containing 0.15% by volume ethanol). The position of the zones was detected by shining ultraviolet light on the chromatogram. Two narrow distinct zones (coned upward) and one indistinct one were formed, and these were cut out (this was diffi­ cult as cones were close together) and eluted with chloro­ form, Acetone was also successfully used as an eluent.

The top diffuse band, which was not displaced, was about 10 mm. wide. Only a few mg, of oily material were eluted from the top band, A second band (convex shaped),

3 mm. in width, was separated from the first band by

120 mm, and fluoresced very brightly in the presence of ultraviolet light. This band gave on elution 0,090 g, of an oily material. There were 20 mm, between the second and third band. From the third band, which was also coned in shape, there was eluted 0,083 g, of an oily substance.

The material in the lower two bands was the magnesium salt of benzylated £-gluconic acid.

The sirups obtained from zones two and three were further purified by one more chromatographic treatment effected by the same method as described above. -109- Gonversion of the magnesium salts into the free

benzylated D-gluconic acid was carried out by dissolving

them in ether-dilute hydrochloric acid (2N) and vigor­

ously shaking the mixture. The ether layer was washed

several times with distilled water, dried with Drierite,

filtered and finally evaporated under reduced pressure.

Anal. Calcd, Zone 3 (Bottom one) for C^HyOy(C^H^CHg)^.

G, 76,lA; H, 6.55. Found: C, 78.44? H, 6 ,64.

Analyst; Dr. Huffman.

3• Using Benzyl Ghloride as Benzvlating Agent

An attempt was made to prepare penta-0—benzyl-D-

gluconic acid by reacting D-gluconic acid pentaacetate

with benzyl chloride and powdered potassium hydroxide

according to the procedure developed by Zemplen and co-

workers (117).

D-gluconic acid pentaacetate (5 g.) was added to

a solution of benzyl chloride (75 ml,) and anhydrous

toluene (70 ml.). Powdered potassium hydroxide (100 g.)

was added and the reaction mixture vigorously stirred

and heated for about 8 hours at 90-100®,

The product was extracted in the manner as described

in the preceding section, wherein benzyl bromide was

used as the benzylating agent; yield, 2,0 g; m.p. 90-

92°. Repeated recrystallizations from light petroleum

ether failed to produce a pure compound; m.p. 105-118®, —HO—

This compound had quite strong acid properties.

Anal, Caled, for Molecular weight, 64.7, F ound .ty titration from methanol-water with standard sodium hydroxide, 162,

E . Preparation of Pentabenzyl-D-Glucose Diethyl Mercaptal

1, Preparation of D-Glucose Diethyl Mercaptal

D-Glucose diethyl mercaptal (64. g.) was prepared ftom D-glucose (70 g, ) and ethyl mercaptan (4-0 g, ) in the presence of concentrated hydrochloric acid (70 g,) according to the method of Fischer (123),

2, Attempted Benzylation of Alkoxide of D- Glucose Diethvl Mercaptal

An a ttempt was made to benzylate the potassium alkoxide of 2,-glucose diethyl mercaptal xdfch benzyl bro­ mide according to a modification of the method of Muskat

(116) as improved by Wolfrom and co-workers (126),

To a solution of D-glucose diethyl mercaptal (10 g,) in liquid ammonia (1 liter), potassium (5 g.) was added until the solution remained blue in color for at least one hour. After the ammonia was allowed to evaporate, anhydrous ether (100 ml,) was added and subsequently evaporated under reduced pressure in order to remove all ammonia. Some of the 0-potassium alkoxide was yellowish

in color; the larger part was white, To the alkoxide. —JLJ.X— benzyl bromide (100 g.) was added and the reaction mixture maintained at room temperature for 5 hours and

at 50^ for one-half hour. Some fumes were produced

during the reaction. The brown tarry mixture was fil­

tered and washed with hot dioxane. Evaporation of the filtrate under high vacuum at 90° left a brown viscous

oil; yield, 25 g. This oil was dissolved in hot anhydrous alcohol (200 ml.) and repeatedly treated with Darco—G-60 to remove the color, but with no success. The dark o solution was left stand at 0 for a week, but the benzy­ lated product did not crystallize.

3* Synthesis of Pentabenzyl—D—Glucose Diethyl Mercaptal

(a) First Benzylation of D-Glucose Diethyl Mercaptal

D-Glucose diethyl mercaptal was partially benzy­ lated according to a slight modification of the procedure of Zemplen and co-workers (117).

In a one liter round-bottom 3—neck flask (protected from moisture with a calcium chloride tube) fitted with a mercury-seal stirrer, reflux condenser, and a ther­ mometer, was placed thoroughly dried D-glucose diethyl mercaptal (20 g,). To this was added 200 ml, purified anhydrous dioxane (131) and the mixture stirred and heated

(131) L, F, Fieser, ^Experiments in Organic Chemis­ try,” 2nd Edition, Part II, D. C. Heath and Company, Hew York, N. Y,, 1941, p. 369. -112- at 60° until complete solution was effected. Freshly fractionally distilled benzyl chloride (150 ml.) and powdered potassium hydroxide* (4.0 g, ) were added. The

* A product of Bgkers containing 2.% potassium car­ bonate and showing 86^ analysis, mixture was stirred and the temperature of the reactants not' allowed to rise above 90° (the reaction is exother­ mic), After the reaction was allowed to continue for 2 hours at 80-90°, another quantity of benzyl chloride

(50 ml.) and powdered potassium hydroxide (20 g.) was added and the temperature maintained at 80—90° for an­ other one hour, whereupon a final quantity of benzyl chloride (100 ml,) and powdered potassium hydroxide

(40 g.) was added. Heating and stirring of the mixture o were maintained for a further 5 hours at 80-90 , and it was then left overnight at room temperature.

The reaction mixture was centrifuged and the super­ natant liquid filtered. Centrifugation of the solution aided the filtration. The solids were washed with two small portions of anhydrous benzene. The filtrate was distilled under reduced pressure ( 1 mm,) and at a tem­ perature not exceeding 90°, Residual volatile material was partially removed by the addition of three portions

of absolute alcohol (25 ml. each) followed by one of benzene. These solvents were distilled under reduced pressure. The partially benzylated product was a light -113- yellow viscous sirup.

Complete removal of all benzyl chloride and benzyl alcohol was attained by steam distilling the yellow sirup until the distillate was clear. The benzylated sugar was extracted with two portions of chloroform and the organic solvent subsequently washed with water, dried with Drierite, filtered and treated with Darco G-60 (de- colorizer). The chloroform was evaporated under reduced pressure leaving a light yellow sirup.

The Molecular Weight of Partially Benzylated

D-Glucose Diethyl Mercaptal A 0.2360 g. sample of partially benzylated £- glucose diethyl mercaptal depressed the freezing point of A , 3540 g. of benzene 0.51°. The molecular weight found was 544. The calculated molecular weight of tri-

0-benzyl-^-glucose diethyl mercaptal is 557.

(b) Second Benzylation

To â; solution of partially benzylated D-glucose di­ ethyl mercaptal (11 g.) in benzyl chloride (50 ml.), powdered potassium hydroxide (11 g,) was added and the mixture stirred and heated at 80° for 3 hours. A further amount of powdered potassium hydroxide (4 g.) was then added and the reaction allowed to continue at 90° for 3 hours and then left overnight at room temperature. It was noticed that the color of the reaction mixture changed from an orange to a light yellow color as the reaction —X14-” proceeded. The product uas freed of volatile contami­

nants in a similar manner as described in the first

benzylation or by distilling it in a Hickman pot still

at a pressure of S x 10"^ mm. and a temperature not ex­

ceeding 65°, followed by steam distillation of the sirup.

Anal. Calcd. for 0-pentabenzyl D-glucose diethyl mercaptal: C, 73.33%} H, 7.11%

Found: G, 72,16% (W); H, 7.14% (W),

Analyst: R. L. Warfel (W), The Ohio State University.

(c) Third Benzylation

The partially benzylated D-glucose diethyl mercaptal

(8,8 g.) was dissolved in benzyl chloride (30 ml.). To

the solution, powdered potassium hydroxide (8 g.) was added and the mixture stirred and heated at 80-90° for

2 hours. A second quantity of potassium hydroxide (5 g.) and benzyl chloride (10 ml.) was then added and the mix­

ture heated and stirred for another 4 hours. After the reaction mixture was cooled, it was centrifuged; the

supernatant liquid filtered, and the solids washed with several small portions of benzene. The combined clear

solution was freed of volatile matter as in the first benzylation. The benzylated sugar was extracted with ether (200 ml.), the ether washed with water, dried, and decolored with Darco—G-60, Evaporation of the solvent left a light yellow sirup; yield, 8.8 g. This sirup was very soluble in ether, chloroform, benzene and light -115- petroleum ether. It was slightly soluble in methanol and ethanol and insoluble in water. The benzylated compound would not crystallize in methanol or ethanol (absolute or 95%)f but came down as an oil. It would not crystal= lize from ether-light petroleum ether when cooled to —60°.

The highly viscous light yellow sirup would not distil in a Hickman pot still at a pressure of S x lO"”^ mm. and a temperature as high as 80°. The yellow sirup solidified at —10 to —12 ,

Anal, Calcd, for C^HyO^ (CHgC^^H^) ^ (SG2H^)2 :

C, 73.33,* H, 7,11,

Found: C, 74.66 (W); H, 7,07 (W),

Analyst: R, L, Warfel (W), The Ohio State University,

The Molecular Weight of Product from Third

Benzylation of D-Glucose Diethyl Mercaptal A 0,1643 g, sample of the same product depressed the freezing point of 4.2972 g. of benzene 0.27°. The molecular weight found was 725, The calculated mole­ cular weight of 0-pentabenzyl-D,-glucose diethyl mercaptal is 737,

(d) Chromatography of 0-Pentabenzyl-D-Glucose

Diethyl Mercaptal

An amount of 1,0 g . of crude 0-pentabenzyl-D-glucose diethyl mercaptal was dissolved in benzene (4-5% solution).

This solution was added at the top of a 120 x 77 mm.

(diam,) column of a mixture of Magnesol (130)/Celite -116-

(5:1 by weight). The chromatogram was developed with

500 benzene (132)/l absolute ethanol. The zones were

(132) All benzene employed was free of thiophene, located with ultraviolet light; the top zone, about 4 cm, from the top, was 0,3 cm, in width, while the bottom zone was very diffuse and about 6 cm, in width and ex­ tended to the bottom of the column. The column was extruded and the two zones, after separation, were eluted with absolute alcohol or acetone. After the solvent was distilled under reduced pressure, the material of each zone was extracted with ether and the ether subsequently distilled. From the top and bottom zones there were ob­ tained 0,17 g. and 0,80 g, respectively, of light yellow sirup.

Anal. Bottom zone» Calcd. for C^HyO^(CH^G^H^)^(SC^H^)^:

0, 73,33; H, 7,11; S, 8,70,

Found: G, 73.48 (W); H, 7.19 (W); S, 8,44,

+ 1,3° (c 3,6, chloroform),

F, Preparation of Pentabenzvl-aldehvdo—D-Glucose

Pentabenzyl—D-glucose diethyl mercaptal was demer- captalated with CdGO^ - HgClg - HgO in acetone according to the method of Wolfrom and co—workers (69).

An amount of 2,5 g, of mercuric chloride was dis­ solved in 10 ml, of acetone and placed in a 58 ml, two—necked flask fitted with an efficient mechanical -117- stirrer. Finely powdered cadmium carbonate (4 g.) and

water (0,35 ml.) were added and the mixture stirred

vigorously for 15 minutes, whereupon crude pentabenzyl-

D-glucose diethyl mercaptal (l g,), dissolved in acetone

(10 ml,), was added slowly to the stirred mixture. The

vigorous mechanical stirring was maintained for a period

of approximately 20 hours at room temperature.

The mixture was filtered in a flask containing

finely powdered cadmium carbonate (3 g ,),the residue

was well washed with acetone (15 ml,) and the solvent

removed under reduced pressure (25-30®) in the presence

of the cadmium carbonate. The residue was extracted

with several portions of warm ethanol-free chloroform

and the extract washed with an aqueous solution of potass­

ium iodide and with water until free of halides. The

dried chloroform extract was treated with decolcr izing

charcoal and the solvent removed under reduced pressure.

The product was a viscous sirup, light yellow in color;

yield, 0,52 g.

G, Synthesis of Pentabenzyl-li-Gluconic Acid

Pentabenzyl-D-gluconic acid was prepared from penta-

benzyl-aldehvdo-D-glucose by oxidation with potassium

hypoiodite according to the method of Moore and Link (133)*

(133) S. Moore and K, P. Link, J, Biol. Chem,, m , 293 (1940). -118-

In a 2—neck flask fitted with a stirrer and a dropping funnel were placed iodine (0,40 g.) and methanol (8 ml,).

The stirrer was started and when solution of the iodine was effected, nentabenzyl-aldehvdo-D-glucose (0,50 g,) dissolved in methanol (10 ml,) was added. Immediately thereafter, a U-% methanolic solution of potassium hydrox­ ide (9 ml.) was added dropwise during a period of time of 10 minutes. After this time, the reaction mixture was stirred for a further 10 minutes, whereupon another quantity of the potassium hydroxide solution (7 ml.) was added dropwise. The reaction mixture was stirred for o one hour and then left stand at —10 for several days.

No precipitate was formed.

The reaction mixture was washed with 3 portions

(75 ml, each) of light petroleum ether to free the mix­ ture of benzylated D-glucose (not oxidized). After the methanol solution was acidified with hydrochloric acid

(pH 7), it was distilled under reduced pressure to com­ plete dryness. To the dry residue, hydrochloric acid was added (to pH 3) and the mixture was then extracted with ether (4 portions). The combined ether extracts were filtered, washed with water until free of chloride, then with sodium thiosulfate and again with water. The ether solution was dried, decolorized, filtered, and distilled under reduced pressure. The product was a yellowish oil. The conversion of the benavlated-aldehydo-

D_glucose into benzylated D—gluconic acid was estab- - 119 - lished hj titrating the latter in ether—water with standard sodium hydroxide. This titration required more than a week of time, and the resulting sodium salt of the benzylated D—gluconic acid formed a gel—like mixture with the ether-water* -120-

IV. DISCUSSION

A . General

The main objectives of this research were to pre­

pare pentabenzyl-D—gluconic acid in crystalline condition

and then to make application of this compound in synthe­

ses, One of the easiest approaches to the first objective

was by preparing tho alkali alkoxide of D-gluconamide

and reacting the latter with benzyl chloride. Upon

deamination of the fully 0—benzylated D-gluconamide we

hoped to obtain pentabenzyl D-gluconic acid. This

method proved to be time-consuming because of the very

slow reaction between benzyl chloride and the alkali alkoxide of D-gluconamide, and also because of the need

of repeated rebenzylations. Ag a consequence, it was

hoped by this Laboratory that the Zemplen method (117)

of reacting directly D-gluconic acid pentaacetate with

benzyl chloride in the presence of potassium hydroxide

might give the desired benzylated acid. Although no

success was obtained by using benzyl chloride, the more

reactive benzyl bromide was found to work with limited

success. It was a great disappointment to this Labora­

tory that the benzylated D-gluconic acid did not cry­

stallize. Moreover, the product was obtained in low

yield. As a result, the more lengthy procedure of

benzylating ^-glucose diethyl mercaptal was carried out,

followed by demercaptalation and oxidation of the resulting —3.21— benzylated D-glucose. These methods, along with others, are discussed in the following sections,

B, Attempted Complete Benzylation of

■GXh .g.9,hawi .4g. 1. Attempted Benzylation of (O—Potassium)

Alkoxide of ^-Gluconamide with Benzyl

Chloride

An attempt was made to prepare penta-O-benzyl-D— gluconamide by first preparing the potassium alkoxide of

D-gluconamide and subsequently reacting the latter with benzyl chloride according to the procedure of Muskat

(116) with the improvement of Wolfrom and co-workers

(128). It was found that the mono potassium alkoxide of D—gluconamide was insoluble in liquid ammonia. If all ammonia was completely removed from the alkoxide, benzyl chloride reacted very slowly with the latter. In a test benzylation of the potassium alkoxide of D—galac- tonamide with benzyl chloride in xylene, it was found that the reaction was incomplete after the reaction mix­ ture was heated at 90°for over 30 hours. The presence of liquid ammonia with the benzyl chloride greatly ac­ celerated the rate of the reaction, the reaction usually being complete in about 10 hours. However, benzylamines were formed in the side reaction between banzyl chloride and ammonia. The partially benzylated D-gluconamide was rebenzylated several times, the last time in the absence —122— of liquid ammonia, Tribenzylamine, a major contaminant, was removed by fractional c rystallization, and the re­ maining sirup steam distilled. The residue was extracted with ether, and the solvent subsequently removed under reduced pressure yielding a sirup which would not crystal* lize. As the molecular weight of this material was found to be 3 6 7, it indicated that at best only a di—0-benzyl ether of D-gluconamide had been obtained (calculated molecular weight of di-0—benzyl ether of D-gluconamide is 3 7 5). This work, involving benzylation of the 0-alkali alkoxide, is best done in the absence of liquid ammonia.

It is possible that benzyl bromide would be a better benzylating agent than benzyl chloride because of its greater reactivity. However, in either case, it would be necessary to rebenzylate many times before a full degree of benzylation might be attained. As each step was time-consuming and the yield very low, the method was abandoned.

2. Attempted Benzylation of D-Gluconamide with Sodium Naphthalene Reagent and

Benzyl Bromide

D—Gluconamide was reacted with sodium naphthalene

reagent dissolved in ethylene glycol dimethyl ether,

and the resulting sodium alkoxide treated with benzyl -123- bromide according to the procedure of Sowden and Fischer (121),

The slight solubility of D—gluconamide in hot

ethylene glycol dimethyl ether and the insolubility of

the sodium alkoxide of D-gluconamide in the same solvent

were two great limitations of this attempted procedure.

An unsuccessful attempt was made to separate the benzy—

lated sugar from the tarry material which was formed in

the reaction,

C, Attempted Preparation of Pentabenzyl-D—

Gluconic Acid

1, Using Benzvl Bromide

D—Gluconic acid pentaacetate was benzylated with benzyl bromide and powdered potassium hydroxide accord­ ing to a modification of the procedure used by Zemplen and co-workers (117), The crude oily product was freed

of volatile matter by steam distillation (yield, about

30% of theor,). The crude product was then subjected to fractional distillation at a pressure less than

0,2 mm, and a temperature up to 130°, As the material would not distil under these conditions, the method was abandoned. It was then dissolved in light petroleum ether and when the solution was cooled slowly, an oil

settled, A similar result was obtained when absolute alcohol was used as a solvent. This partially purified product, when dissolved in ether and titrated with —124-—

standard sodium hydroxide, gave a molecular weight of

680 (the calculated molecular weight of pentabenzyl-D-

gluconic acid is 6 4 7),

As a result, the crude benzylated acid was then sub­

jected to an exhaustive chromatographic fractionation

on Magnesol-Gelite. Development was effected with

chloroform (containing 0,75% ethanol)» Two sharp coned

zones, at a maximum distance of 2 cm. apart, were formed

soon after development of the column began. A narrow

diffuse band was also formed on the top of the column.

The three bands were easily detected with ultraviolet

light. As it was impossible to separate clearly the two

lower zones, each was rechromatographed. These zones

were cut out and eluted with acetone or chloroform.

When the solvent had evaporated, oils were left which

failed to crystallize from organic solvents. Tests of

the material in the lower zones showed that the magnesium

salts of the benzylated D-gluconic acid had been formed

when the material was chromatographed. As a consequence,

the free benzylated D-gluconic acid was liberated by

treatment with hydrochloric acid. Analysis of zone three

(lower one) showed that the material might have been

slightly contaminated (found C, 78.44^; H, 6 .6 4%)* The

calculated elemental analyses of pentabenzyl-D-gluconic

acid are C, 76.14% and H, 6,55%. As only 0.083 g. of benzylated acid (Magnesium salt) had been obtained from -125- a possible 0,185 g, of free acid, this shows that about

4-0-50% of the material was likely fully benzylated D—

gluconic acid. However, when one considers the yield of

crude product (about 30%), the over-all yield of fully

benzylated D-gluconic acid was about 10-15%.

No attempt was made to analyse the material from

zone two. Since it was held more tightly by the adsor­

bent, it is likely that this material was a partially

benzylated D-gluconic acid,

2, Using Benzvl Chloride

In connection with a study of the use of benzyl chloride instead of benzyl bromide for benzylation of

^—gluconic acid pentaacetate, it was found that the acetyl groups were not replaced by benzyl groups, D—

Gluconic acid pentaacetate was, however, deacetylated,

From 5 g. of starting material, 2 g, of a crystalline product having a molecular weight of 162 was obtained.

This material had acidic properties and was easily

titrated with standard sodium hydroxide. No further work was done to establish definitively the structure

of the recovered material.

D. Synthesis of Pentabenzyl—^-Glucose Diethyl

Mercaptal

1, Preparation of D—Glucose Diethyl Mercaptal D-Glucose diethyl mercaptal was prepared from —126«—

D-glucose and ethyl mercaptan in the presence of con­

centrated hydrochloric acid according to the procedure

of Fischer (123)*

2. Attempted Benzvlation of (O-Potassinm)

Alkoxide of D—Glucose Diethyl Mercaptal D-Glucose diethyl mercaptal, dissolved in liquid ammonia, was titrated with metallic potassium according to the method of Muskat (ll6) as improved by Wolfrom and co-workers (128), The resulting potassium alkoxide

of the mercaptal was then reacted with benzylb romide.

Under the conditions used, as described in the

experimental section (see Section III, E, 2), there may have been considerable decomposition of the starting material as the reactants were noticed to fume, This was corroborated by the fact that considerable tarry material was formed. Attempts to remove the black color or

to crystallize the oily residue were unsuccessful,.

3, Synthesis of Pentabenzyl-D-Glucose

Diethvl Mercaptal

D-Glucose diethyl mercaptal was fully benzylated with benzyl chloride and powdered potassium hydroxide

according to a modification of the procedure of Zemplen

(117), Two rebenzylations were required in order to benzylate fully most of the starting material. In the

first benzylation, the mercaptal was dissolved in dioxane -127- and then treated with benzyl chloride and powdered

potassium hydroxide. The resulting benzyl ether had a

molecular weight of 54-4 (the calculated molecular weight

of tri-O-benzyl-D-glucose diethyl mercaptal is 557), When the partially benzylated mercaptal was rebenzylated

(using no solvent), the new product had a carbon and a hydrogen content of 72,18% and 7,08%, respectively (this

corresponds to more than 4.5 benzyl groups per molecule;

theor, C, 73,33%; H, 7,11%). This product was rebenzy— lated a third time with benzyl chloride and powdered potassium hydroxide in t he same way as done in the first rebenzylation. The molecular weight of this final product was determined by a depression of freezing point of ben­

zene and was found to be 725 (l5%), The calculated molecular weight of fully benzylated D-glucose diethyl mercaptal is 737,

It was very disappointing to this Laboratory that pentabenzyl-D-glucose diethyl mercaptal failed to cry­

stallize. The benzylated mercaptal separated as a solid when an ether solution of it was rapidly evaporated.

This solid could be filtered but it changed rapidly to an oil when left at room temperature. Attempts to obtain a crystalline product by dissolving the benzylated sugar in ether-light petroleum ether and subsequently cooling the solution to —6 0° were also unsuccessful.

As a result, crude benzylated D-glucose diethyl •“128”* mercaptal was subjected to chromatographic fractionation on Magnesol-Gelite (5/l). Development was effected with benzene-alcohol (5OO/I) and was continued until the lower diffuse zone (detected by ultraviolet light) was at the bottom of the column. Recovery of the material (yellow in color) from the two zones was almost quantitative; about 80^ of the total material was in the lower diffuse zone and this material was analytically pure pentabenzyl-

D-glucose diethyl mercaptal. Unfortunately, this mater­ ial failed to crystallize.

No attempt was made to analyze the small amount of the material (less than 20^ of the total) obtained from the top narrow zone. It is possible that this com­ pound was tetrabenzyl-D—glucose diethyl mercaptal. If this is the ease, a fourth benzylation with sodium in ether, followed by the addition of benzyl chloride might

serve to benzylate fully the remaining small part of

tetrabenzyl-D-glucose diethyl mercaptal.

The yields of crude benzylated D-glucose diethyl mercaptal (after steam distillation of all volatile matter) from 5 g. and 20 g, of D-glucose diethyl mer­

captal were 8,8 g, and 36,5 g., respectively. These values represent over-all yields of 69% and 72% of

theoretical, respectively, in the two separate runs.

It was early observed in the work on benzylation

of the mercaptal (both in the first and latter rebenzy-

lations) that a highly colored compound was first formed -12 9- but the color rapidly became less intense as heating was continued. Levene and Meyer (124), in. their work on the méthylation of D—glucose diethyl mercaptal, had observed that a highly colored product was obtained if heating was too intense or the reaction was continued for too long a period of time, and that the yield of product was decreased under these conditions. It is possible, that in our work, the change of color during the reaction may also be significant,

E. Preparation of Fentabenzvl-aldehvdo-D-Glueose Pentabenzyl-D-glucose diethyl mercaptalwas demer— captalated with CdCO^ - HgClg — E^O in acetone according to the method of Wolfrom and co—workers (69). In this reaction, cadmium carbonate was added to maintain a neutral solution since hydrogen chloride is a by-product of the demercaptalation,

F . Synthesis of Pentabenzyl-D—Gluconic Acid Pentabenzyl-D-gluconic acid was prepared from penta— benzvl-aIdehvdo-D—glucose dissolved in methanol with potassium hypoiodite according to the method of Moore and Link (133), Moore and Link (133 ) foxind that some potassium salts of aldonie acids are soluble, whereas others are not soluble in methanol. It was disappointing to this Laboratory to find that the anticipated potassium salt of pentabenzyl-D-gluconic acid did not crystallize. —130— nor come out of solution, even after standing for a week at —10°. As a result, the free acid was liberated by treatment of the solution containing the potassium salt of the sugar acid, with hydrochloric acid. “•131—

V. SUMMARY

1. Three successive benzylations of the (O-potassium) alkoxide of gluconamide in liquid ammonia with benzyl chloride have been found to give benzylated D-glucon­ amide having a benzyl content of 1,9 groups per D- gluconamide molecule in an over—all yield of 9%,

2. Benzylation of £—gluconamide in anhydrous ethylene glycol dimethyl ether with sodium naphthalene reagent and benzyl bromide has been found to be accompanied with troublesome side—reactioiis, the products of which have been difficult to separate from the benzylated sugar amide,

3. A mixture of partially and fully benzylated

D-gluconic acid has been prepared by reacting D—gluconic acid pentaacetate in anhydrous toluene with benzyl bromide and powdered potassium hydroxide, Pentabenzyl-

D-gluconic acid (not quite analytically pure) has been separated from the crude mixture of benzylated sugar

acid by exhaustive chromatographic separation on Mag- nesol-Celite in an over—all yield of 12^,

4. D-Gluconic acid pentaacetate in anhydrous toluene has been found to be deacetylated but not benzylated by the action of benzyl chloride and powdered hydroxide. —132 —

5s» Pentabenzyl-D-glucose diethyl mercaptal has been synthesized by three successive benzylations of

D-glueose diethyl mercaptal with benzyl chloride in the presence of powdered potassium hydroxide. Application of chromatographic techniques to the crude benzylated produ&it has been found to give pentabenzyl-D-glucose diethy]! mercaptal in analytically pure condition (in oily sfcate) in an over-all yield of 5S%.

6a„ Pentabenzvl-aldehvdo-D-glucose (not analyti­ cally characterized) has been prepared by demercaptalating pentabp@îizyl-D-glucose diethyl mercaptal in acetone with mercuric chloride—cadmium oarbonate-water. 7 ^ By the oxidation of penta benzvl—aIdehvdo-D- glucosea in methanol with iodine and potassium hydroxide, pentabesuzyl-D-gluconic acid has been obtained. -133-

VI. CHRONOLOGICAL BIBLIOGRAPHY

(53) H. St, G. Devills, Gompt. rend., 2S. 257 (184-9) j Ann. chim. phys., [3] 28, 24-1 (1850),

(31) H. Klasiwetz, Ann., 119. 281 (1861),

(86) Colley, Gompt. rend., 76, 436 (1873),

(11) L. Boutroux, Gompt. rend., 2Ü» 236 (1880)j A, J, Brown, J. Ghem, Soc,, 172, 435 (1886),

(41) P. Vieille, Gompt, rend,, 21, 135 (1882); Mem. poudres, 2., 212 (1884— 9).

(32) H, Kiliani and S. Kleeman, Ber., 1%, 1296 (1884)»

(24) H, Kiliani, Ber., 12, 767 (1886).

(97) A, Nobel, Brit. Patent 1471 (1886).

(98) Lundhdlm and Sayers, Brit. Patent 10,376 (1889).

(99) Abel and Dewar, Brit. Patents 5614 and 11,664 (1889),

( 8) E, Fischer, Ber,, 22, 799 (lS90),

( 3) E, Fischer, Ber,, 22, 2625 (1890).

( 6) M, Schnslle and B . Tollens, Ann,, 271. 81 (1892),

(25) H, Kiliani and H, Sanda, Ber., 26, 1650, 1654 (1893). (123) E, Fischer, Ber,, 2J, 673 (1894). (73) H, von Pechmann, Ber,, 2%, 1888 (1894).

(7 4) E. Bamberger and E. Renauld, Ber,, 28,, 1683 (1895). (4 3) Warren, Ghem, News, 239 (1896).

(28) G, Romijn, Z, anal, Ghem., 2A, 34-9 (1897). (4 0) W, Will add F, Lenze, Ber,, 2 1 , 68 (1898); J, A, Wyler (to Trojan Powder Co.). Ü, S, 2,039,045 and 2,0 3 9 ,0 4 6 (April 28, 1936). - 1 3 4 - (33 H. A. Clowes and B, Tollens, Ann., 310^ 164 (1899); C. S. Hudson and H. S. Isbell, J. Am. Gh.em. Soc,, 2225 (1929); J. Research Natl. Bur. Standards, S., 57 (1929).

(4-4- G. Lunge and E. Weintraub, Z. angew. Chem., 12, 445 (1899). (72 H. von Pechmann, Ber. , 22.7 956 (1900)*

(85 W. Koenigs and E. Knorr, Ber., 2Â7 957 (1901).

(4-9 M. H. Duval, Bull. soc. chim., 22, 601 (1903); Gompt. rend.. 137. 571, 1262 (1903).

(95 A. P. Sy, J. Am. Chem. Soc., 2^, 549 (1903). (16 N. A. Maximow, Ber., deut. botan. Ges. , 2_2, 225 (1 9 0); 4 D. Müller, Biochem. Z., 122, 136 (1928); cf. J. B. Sumner and K. Myrbfick, "The Enzymes," Vol. II, Part I, Academic Press, Inc., Publishers New York, N. Y., 1951, pp. 764-767.

(100 E . Fischer and 0. Warburg, Ann., 340, 171 (1905).

(4-2 E. Berl and W. Smith, Ber., 22» 903 (1907); A1. 1837 (1908); E . Berl, U. S. Patent 2,384,415 (Sept. 4» 1945); C. Trogus, Ber., 64. B . 405 (1931)

(54 Gibson, Proc. Roy. Soc. Edinburgh, 28, 705 (1908). (26 J. TJ. Nef (and Lucas), Ann. , 376. 55 Note (1910); H. Spoehr (and Rosario), Am. Chem. J., 22.» 24-0 (1910),

(94 J. Walter, Z. angew. Ghem., 22» 62 (1911).

(55 A. Dufay, Chem. News, 106. 211 (1912),

(75 H. Staudinger and 0. Kupfer, Ber., 25.» 501 (1912),

(89 Ef, Berger, Bull. soc. chim., IJL [4] » 1049 (1912), (92 D. Florentin, Z. ges. Schiess-u. Sprengstoffw, 8, 6 (1913);cf. C. A., 7, 1290 (1913).

( 4 J. U. Nef, Ann. , 4.03. 322 (1914) ; 0. F. Heden- burg, J. Am, Chem. Soc., 2Z» 345 (1915).

(29 R. Willstëtter and G. Schudel, Ber,, 780 (1918), -135- (37) M. R. A, Weerman, Rec. -trav, chim., 22, 24 (1918),

(36) G. S. Hudson and S. Komatsu, J. Am. Chem, Soc., Al,1 TTy*» /1 al a\ (111) M, Gomberg and G. G, Buchler, J, Am. Chem. Soc., Al, 1904 (1921).

(115) G . A, Kraus and G. F. White, J. Am. Ghem. Soc., Al, 769 (1923). (5 6) L, B. Haines and H. Adkins, J. Am. Ghem. Soc., A2, 1 4 1 9 (1 9 2). 5 (112) K. Freudenberg, H. von Hochstetter and H. Engels, Ber., 21, 666 (1925).

(1 1 4) L. Schmid and B, Becker, Ber., 21, 1966 (1925).

( 1) P. A. Levene and H. S. Simms, J. Biol. Chem., 62, 31 (1 9 2). 5 ( 2) W. Charlton and W. N. Haworth, J. Ghem. Soc., 8 9 (1 9 2); 6 ¥. N. Haworth and V. S. Nicholson, ibid.. 1899 (1926).

(1 2) K. Bernhauer, Biochem. Z., Cl. XXII, 296, 312, 3 2 4 (1926).

(1 2 4) P. A, Levene and G. M. Meyer, J. Biol, Chem., 6 2 , 175 (1 9 2). 6

(1 8) Rothin and Schweiz, Med. Wochen., 2 2 , 388 (1927): Kottman and Schweiz, Med. Wochen., 2 2 , 409 (1927). (30) W. F, Goebel, J. Biol. Chem., 22, 809 (1927).

(38) G. ZemplSn and D. Kiss, Ber., 60, 165 (1927),

(4 6) L. A. Pinck, J. Am. Chem. Soc., A2, 2536 (1927); Ind. Eng. Chem., 12, 1 2 4I (1930).

(1 1 0) K. Freudenberg, W. Dlirr and H. von Hochstetter, Ber., 6%, 1739 (1928); German Patents 407,487 (1 9 2) 3 and 417,926 (1924).

(7 6) H. Meerwein and W. Burneleit, Ber., 61, 1845 (1928)

(1 1 3) K. Freudenberg, W. Dftrr and H. von Hochstetter 9 Ber., 61, 1935 (1928). —136—

(125) M. L.Wolfrom, J. Am. Chem. Soc., 2188 (1929).

(19) F, P. Nebenhauer, Ind. Eng. Ghem., 2^, 54 (1930); E. 0, Whittier, Ghem. Revs., 2, 85 (1925).

(45) E. Berl and G. Rneff, Ber., 63 B . 3212 (1930); Gellnlosechem., 12, 53 (1931)î 14, 115 (1933); E . Berl, Ind. Eng. Ghem. Anal. Ed., ij., 322 (1941)

(79) F. Arndt and J. Amende, Z. angew. Ghem. , 42.» 444 (1930); F. Arndt and H. Scholy, ibid, j, 46. 47 (1933); F. Arndt, "Organic Snytheses," Vol. XV, John Wiley & Sons, New York, N. Y., 1935; pp. 3» 48 . ( 7) H. S, Isbell and H. L. Frush, Bur. Standards J. Research, 6, 1145 (1931); il, 649 (1933); K. Rehorst, Ber., 163 (1928); 6^, 2279 (1930).

(22) S. Aeree, ü. S. Patent 1,816,136 (July 28, 1931).

(34) H. S. Isbell and H. L. Frush, J. Research Natl» Bur. Standards, 6, 1145 (1931); R. S. Isbell (to the Government of the ü. S., represented by the Secretary of Commerce), Ü. S. Patent 1,976,731 (Oct. 16, 1934). (82) P. Brigl, H. Mûhlschlegel and R. Schinle, Ber.,. 64» 2921 (1931). (23) H. S. Isbell and H. L. Frush, Bur. Standards J. Research, 8, 332 (1932).

( 9) H. T. Bonnett and F. ¥. Upson, J. Am. Ghem. Soc., ii, 1245 (1933). (77) E. G. S. Jones and J. Kenner, J. Chem. Soc., 363 (1933); D. W. Adamson and J. Kenner, J. Ghem. Soc., 286 (1935). (126) P. Brigl and R. Schinle, Ber., M » 325 (1933).

(106) E. Thielepape, Ber., 66 B . 1454 (1933). (39) J, ¥. E. Glattfeld and D. Macmillan, J. Am. Chem. Soc.-, i6, 2481 (1934). -137- (57) (a) Z. Rogovln and K. Tikhonov, Iskusstvennoe Volokno, No. 7, 4-1 (1934); 1, No. 5, 34 (1934); (b) Gellnlosechem., 16, 11 (1935); M , 102 (1934). (81) L. F, Audrieth, Ghem. Revs., 1^» 175 (1934).

(116) I. E, Muskat, J, Am. Chem. Soc., 693, 2449 (1934); S. Sdtzberg (to Atlas Powder Go,). y. S. Patent 2,234,200 (Mar. 11, 1938).

(27) 0. Spengler and H. Pfannenstiel, Z. Wirtschafts- gruppe Zucherind, 8j^, Tech. Tl, 547 (1935).

(58) R. Dalmon, J. Ghedln and L, Brissaud, Gompt* rend., 2 ^ , 6 6 4 (1935).

(5 9) R. Dalmon, Gompt. rend., 2 01, 1123 (1935).

(1 2 2) N, D. Scott, J. T. Walker and V. L, Hansley, J. Am. Chem. Soc., M , 2442 (1936); J. T. Walker and N. D. Scott, ibid.^ 60. 951 (1938).

(1 0 5) R. T. Major and E. W. G0 0k, J . Am. Chem. Soc., 2 4 7 4 (1936). (6 3 ) R. T . Major and E. W. Gook, J. Am. Ghem. Soc., 2 4 7 7 (1936).

(13) A. J. Moyer, P. A. Wells, J. J. Stubbs, H. T. Herrick and 0. E. May, Ind. Eng. Chem., 29, 77 (1 9 3); 7 E. A. Gastrock, N. Porges. P. A, Wells and A. J, Moyer, ikid., 782 (1938;; N. Porges T* F. Clark and S. I. Aronovsky, ibid.. 33, IO65 (1 9 4)► 1 (6 0 ) T, Drbanski and Z. Janiszewski, Roczniki Ghem., 17, 349 (1937),

(117) G, Zemplen, Z. Gsiirtts and S. Angyal, Ber., 70 B , 1848 (1 9 3). 7

(68) G . D. Hurd and J, C. Sowden, J. Am. Chem. Soc., 60, 2 3 5 (1938). (70) J, B. Robbins and F. W. Upson, J. Am. Chem. Soc., M , 1788 (1938).

(9 0) R, Angeli- Z. ges. Schiess-u. Sprengstoffw, 113 (1938). " X 3 8 “

(93) R» Dalbert, Mem. poudres, 28, 14.7 (1938); cf. C. A., li, 7569 (1939).

(69) M. L. Wolfrom, M. Konigsberg and D. I. Weisblat, J, Am, Chem. Soc., 574- (1939).

(15) J. J. Stubbs, L, B. Lockwood, E. T. Roe, B. Tabenkin and G, E, Ward, Ind, Eng, Ghem.. 32. 1626 (194-0); A. J. Kluyner and A. G. J, Boezaardt, Rec. trav, chim., ï2» 609 (1938). (17) A, J. Moyer, E. J. ümberger and J, J, Stubbs, Ind, Eng. Chem., 1379 (194-0).

(35) R, Pasternack and P. P. Régna (to Charles Pfizer & Co.), U. S. 2,222,155 (Nov. 19, 194-0); E. W. Cook and R, T. Major, J. Am. Chem. Soc,, 773 (1935).

(83) G. B. Robbins and F. W, üpson, J. Am, Chem, Soc,, 6^, 1074- (1 9 4); 0 M. L, Wolfrom and H, B. Wood, J, Am. Chem. Soc., 22, 730 (1951). (118) J. S. D. Bacon, D. J, Bell and J, Lorber, J, Chem. Soc., 453 (1940); D . J. Bell and J, Lorber, ibid., 1 1 4 7 (1 9 4), 0

(127) M, L, Wolfrom, D. Weisblat and A, Hanze, J. Am. Chem, Soc., 62, 3 2 4 6 (1940).

(1 3 3) S, Moore and K. P. Link, J. Biol. Chem., 133, 293 (1 9 4). 0 (20) H, Knobloch and II. Moyer, Biochem, Z., 307. 285 (1 9 4). 1 (5 0) S. E. Forman, C. J. Carr and J. C. Krantz, Jr., J. Am, Pharm. Assoc., 20, 132 (1941).

(6 4) M, L, Wolfrom, D. I. Weisblat, W. H, Zophy and S. ¥. Waisbrot, J. Am. Chem. Soc., 201 (1941). (1 1 9) M. H. Adams, R, E. Reeves and W. F. Goebel, J, Biol. Chem,, M O , 653 (1941).

(1 2 1) J, G. Sowden and H. 0. L. Fischer, J. Am, Chem. Soc. , 3 2 4 4 (1 9 4). 1 (131). h. F. Fie&er, "Experiments in Organic Chemistry," 2nd Edition, Part II, D. C, Heath and Company, New York, N. T., 1941, p. 369

(1 2 0) R, M. Hann, W. T, Haskins and C. S. Hudson, J. Am. Ghem, Soc., Mi, 986 (1942 ). -139- (65) M. L. Wolfrom, S. W. Waisbrot and R. L, Brown, J. Am. Chem. Soc., 1701 (194-2),

(67) M. L. Wolfrom and P. W. Morgan, J. Am. Chem, Soc., M , 2026 (194-2),

(84-) T . L, Davis, "The Chemistry of Powder and Ex­ plosives,'* Vol, II, John Wiley & Sons, Inc., New York, N. Y. , 194-3, p. 238.

(88) T. L. Davis, "The Chemistry of Powder and Ex­ plosives,** Vol. II, John Wiley & Sons, Inc., New York, N. Y. , 194-3, p. 307.

(9 6) T. L. Davis, ”The Chemistry of Powder and Ex­ plosives," Vol. II, John Wiley & Sons, Inc., New York, N. Y . , 1943, p. 298

(1 0 4) H„ A, GdlLdsmith, Chem. Revs., H , 257 (1943).

(6 1) W. W, Lake and J. W. Glattfeld, J, Am, Chem, Soc., 1091 (1944). (107) Dierichs, Report PB866, Office of Technical Services, Dept, of Commerce, Washington, 1945; cf. S. Sussman, Ind, and Eng. Ghem., 2È, 1228 (1 9 4), 6 (1 4) J. R. Porter, "Bacterial Chemistry and Physiology," John Wiley, New York, N. Y. , 1946, p:,- 999.

(2 1) J, R. Porter, "Bacterial Chemistry and Physiology," John Wiley, New York, N. Y., 1946, p. 8I4

(4.7') G, V, Caesar (to Stein, Hall & Oo,, Inc.), Ü. S* 2,400,287 (May I4, 1946),

(4 8) G. V. Caesar and M. Goldfrank, J . Am, Chem. Soc., M , 372 (1 9 4), 6

(5 1) E. Ott, "Cellulose and Cellulose Derivatives," Interscience Publishers, New York, N. Y., 1946, p. 6 3 5, ( 5) M. L, Wolfrom, B. W. Lew and R. M. Goepp, Jr., J. Am. Chem. Soc,, 68, 1449 (1946). (66) M. L. Wolfrom and J, V. Karabinos, J. Am. Chem. Soc,, M, 1 4 5 5 (1 9 4). 6 -±4u- (37) G. Pleury and L. Brisaud, Compt, rend., 222. 1051 (1946). (62) M. Tishler (to Merck & Co.). U. S. 2,424,341 (July 22, 1947).

(10) ¥. W. Pigman and R. M. Goepp, '‘Chemistry of Carbohydrates," Academic Press, Inc., New York, 10, N. Y., 1948, p. 297.

(5 2) W. F. Filbert (to E. I. du Pont de Nemours & Co.) Ü. S. 2,4 4 3 ,9 0 3 (June 22, 1948).

(78) A. F. McKay, J. Am. Ghem. Soc., 20, 1974 (1948).

(7 1) M. L. Wolfrom, J. M. Berkebile and A. Thompson, J. Am. Chem. Soc., 7i, 2360 (1949).

(1 0 3) Mile. G. Nicoud, J. des Recherches du Centre National de la Recherche Scientifique, 286 (1949). (9 1) V. R. Grassie, L. Mitchell, J. M. Pepper and C, B. Purves, Can. J. Res., 28 [B], 4 6 8 (1950).

(109) E . M. Osman, K. C. Hobbs and ¥. E. Walston, Abstracts Papers, Am. Chem. Soc,. 1 1 8 . J. Am. Chem. Soc., 21, 2726 (1951). (8 0) H. J. Backer and Th, J. De Boer. Proc. Koninkl. Nederland. Akad. Wetenschap., 54 B . 191 (l95l)j cf. C. A. 4 6, 1961 (1 9 5). 2

(128) M. L. Woifrom, W. W. Binkley, W. L. Shilling and H. W, Hilton, J. Am. Chem. Soc., 71, 3553 (1951). (1 0 8) J. E. Cadotte, F . Smith and D. Spriestersbach, J. Am. Chem. Soc., 74, 1501 (1952), — 14-1—

VII. ACKNOWLEDGMENTS*

The author wishes to take this opportunity to

extend his sincere thanks and appreciation to Pro­

fessor M. L, Woifrom for his most helpful advice,

assistance and inspiration throughout the entire work

of this research.

He would also like to express his gratitude to

The Ohio State University and to E. I. du Pont de

Nemours and Company for their financial support

through the Research Assistantship. Research Fellow­

ship, and du Pont Fellowship,

He is also indebted to Messr. G. Maher for

assistance rendered and to all the "boys in Sugar

Alley" for their friendship and advice.

See Part I, V, p. 71, “• 14 -2 —

VIII. AUTOBIOGRAPHY

I, Alex RosenthalJ was born in Calgary. Alberta,

Canada, October 15, 1914. I received my elementary

and secondary school education in the public schools

of Scollard, Rumsey and Big Valley, Alberta, After I

received my normal school training at Gamrose, Alberta,

I taught in the public schools of Alberta, My under­

graduate education was obtained at the University of

Alberta, from which I received the degree Bachelor of

Science in 1943 and Bachelor of Education in 194?»

During the major portion of time from 1943 to 1947 I

taught and in addition was Principal of Schools. In

1949 I received the degree Master of Science from

the University of Alberta. While I received my graduate

training at the University of Alberta, I received

financial aid, in the form of a research assistantship,

from the National Research Council of Canada. In

1949 I received from The Ohio State University an

appointment as Research Assistant in Chemistry and

the following year I was appointed Research Fellow,

I held this position for one year, at which time I

was appointed Du Pont Fellow in Chemistry for the year

1951-52.