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The Dehydrohalogenation of Halo-Alkenylamines with Sodium Amide in Liquid Ammonia

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The Dehydrohalogenation of Halo-Alkenylamines with Sodium Amide in Liquid Ammonia THE DEHYDROHALOGENATION OF HALO-ALKENYLAMINES WITH SODIUM AMIDE IN LIQUID AMMONIA By ROBERT FORD PARCELL A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA February, 1950 FHEFACE The presentation of this dissertation material is purposely given in detailed form to faeilit&te duplication 'by future investigators, The procedure followed in the synthesis of various members of a homologous series ie given separately for each compound, even though it is basically the same for all members of the series. In conformity with present usage in research reports, all teatpera* tuxes refer to the centigrade scale; its symbol is omitted. The boiling points are corrected values , and unless otherwise indicated, they represent boiling points at atmospheric pressure. The thermoaetere used in obtaining these boiling points were calibrated against a set of thermometers standardized by the Bureau of Standards. Pressure readings below 10 am. were obtained from a KcLeod gauge; those above 10 am. were obtained from a Ztarasrli gauge calibrated at 4 am. against the McLeod gauge. All fractionations were carried out througi a 90 cn. column pack- ed with one-eighth inch Berl saddles. The atomic refractions used throughout this research in calculat- ing theoretical values of molar refractions were obtained from Karrer, Organic Chemistry . Second English Edition, Elsevier Publishing Co., Inc., 1946, P. 914. The manner of listing references is ths customary one for technical works. Journal abbreviations are the official ones of "Chemical Abstracts." li if- SABLE » CONTENTS Chapter Page PREFACE. , , . , * it I rSTHOIWOTIOH AJTO xm» OF THE IITERASUHB . 1 XX PREPARATION OP IWFHU4EDIATKS . 7 Synthesis of 1-Die thylf^no-3-hro»op:ropens~2 .... 8 Synthesis of l^ipropylasdno-S-broaopropenB-S. ... 9 Synthesis of l-J)iisoproiqrlaaino-»-hifonopropene-2 . 10 Synthesis of 1-Dihuty1anlno-2-hrorx>propene-2 .... 11 Synthesis cf l-Ethyloaino-s-hroDopropene-?? 12 Synthesis of 1-X sopropylariiiK>-2-brorioprop«ne~2 ... 13 Synthesis of l-a^ButylaMno~2>hronopropeae-2 .... 14 Synthesis of l^oayliadne»2~hroiaoprOi>ene-2 ..... 15 Synthesis of N .N-hi s- ( 2-Broao-2-propenyl ) -n- hutylaaine ................... ,,16 III CmUEHAL ?12)CS2WRBS FOLLOWED II? CPiuOflKO OUT K3ACST NS IH LiqUTD AMMONIA, INCLUDING THE PREPARATION OF SODIUM AIUDE it sujtessis car tsstiaey mKu&}V'j&*mc ahxnss 25 Synthesis of 1-Die ttty lntaino-propyne-2 25 Synthesis of 1-Die thylasdno-Tnityne-2 26 Syndesis of l^lothylenino-pentyne-2 27 Synthesis of l^iothyl&jaino-hexyne-2 ^ 20 Synthesis of 1-Die thyIxjaino-hex-5-ea-2-yns ..... 29 Synthesis of 1-Diethyl ouino-heytyne-2 31 Synthesis of l-Diethylaalno-oetyne-2 ........ 32 Synthesis of l-Diisopropylaxaino-propyae- 2 . ..... 33 111 6 TAHLS OF COHTBHTS (Continued) Chapter H^S1 Synthesis of 1-Dii sopropylrjaiiw-hutynft-2 ...... 34 .Synthesis of 1-2H1 3oi>ro::ylsMno-pQntyno-2 3 Synthesis of l^iisoyropylEjidJio-^ayno-S ...... 37 Synthesis of l-3)iinopxni>ylrxnino-hep tyno-2. .... 38 Synthesis of 1-J3iisopropylpkIuo-octyne-2 ...... 3? Synthesis of l^ipi^ylj>*Tino-proiyne-2 ....... 40 Synthesis of l^ipr^ylrjaii»-TjutynB-2 41 Synthesis of l-Mpropylruino-peatyne-2 . 42 Synthesis of X^propylRBdno^.e3yne-2* 43 Synthesis of l^ipropylaslno-heptyne-2 44 Synthesis of l^ipropylaadao-octyne-2. 45 Synthesis of 1-3ifratylGnlno-propyne-2 . ....... 4 Synthesis of l-DiT?i1^1etfino-'btttyne-2 47 Synthesis of l-IHbutylexiino-pentyne-2 48 Synthesis of l-31Taxtyla!3ino-hexyi»-2 ........ 49 Synthesis of l-Dihutylsaino-heptj'ne-2. ....... 50 Synthesis of 1-J3 ihutylamJLne-octyn**2 *51 f snRHBSIS GEF TSHTIAHY DI-AC«PYhBSIC AMTSSB 52 Synthesis of »-n-Butyl-di-2-propynylaMne. ..... 52 Synthesis of yl-di-2-hutynylaaine 53 rt suraassis of s-sobstitdtkd 2-piiopmLrDH<riMiiC3B . 54 Synthesis of N-^Pxo >enyl idone-ethylaaine . ..... 54 Synthesis of H-2-Propenylidene-isopropylsjalne. ... 55 It TABUS or CO0TERTS (Continual) Chapter Page Synthesis of N-3-Propenylidene-n-bitylnmino . ... 56 Synthesis of N-2-Propei^lidene-nonylaadne 57 VII TIiaOHETICAL ASPECTS OP THE BEHYDROHAl/iGEHATION OF HALO- AlXEHTLAHXHBS SUB SODIUM AMIDE IH LIQUID AJOOSIA 58 A. Suanary of the Yerious Types of Dehydroholo- genatlon Reactions Described in this Disser- tation, with Establishment of Structure of Resulting Compounds 58 S. Proposed mechanism for the Dehy&rohalo,venation Reactions Described in this Dissertation ... .64 0. Discussion of Deviations la Molar Refractions . 68 SUMMARY. 72 BISLIOORAPHT ................... 76 ACKHOWLhlDGMEBTS 79 BIOGRAPHICAL ITEMS 80 COMMITTO : REPORT CHAPTER I IHTBQDUCTIOS AND REVIEW OF THE LITERATURE The research described in this dissertation was conducted under the sponsorship of the Office of Haval Research, which specified in general that the compounds prepared should he liquids containing one or more amine groups and one or more unsaturated linkages, either ethylenlc or acetylenic. They also specified that the compound? should contain no other functional groups. It was decided that the particular phase of the project represented by this dissertation should be con- fined to the synthesis of acetylenic amines. Although some compounds were prepared which deviated from this general type, they were prepared by the same method which led to the acetylenic amines in other cases, and they form an integral part of this phase of the research. The field of acetylenic amines is a relatively new one, and references to it in the literature are few. The earliest reference to the synthesis of acetylenic amines which was located in the litera- ture described in 1933 the work of Mannich and Chang, who prepared 1- phenyl-3-dialkylamino-propyne-l compounds by the reaction of phenyl- 1 acetylene, formaldehyde, and the appropriate secondary amine. Jones and diethylamine Harssak, and Bader later reacted l-hexyne , formaldehyde, 2 to form 1-diethylamino-heptyne-2 in a similar manner. Several patents have been granted covering the reaction of acetylene, formaldehyde, and amines to form the acetylenic amine, with only slight variations in the method. 3.^ .5 ,6,7 1 2 containing “both Jones , Lacey , end Smith prepared various mine* double and triple bonds by the reaction of alkenynyl halides with ammonia f> and amines. Their paper also describes a study of the rearrangements encountered in these reactions, Johnson reacted 1 ,4-diehlorobutyne-2 with ammonia and amines to form the corresponding acetylenic diamines. 9 In each of the above cates, the acetylenic amine was formed by the reaction of ammonia or en amine with a compound which already con- tained the triple bond. The reaction of acetylene with formaldehyde and an amine to form an acetylenic amine is hampered by the requirement* of conducting the reaction under pressure and in the presence of a catalyst. The reaction of other alkyne* with formaldehyde and asnonia or amines is limited to the higher members of the series, because of the high vola- tility of the lover alkynes. The reaction of an alfcynyl halide with ammonia or an amine is limited by the difficulty of preparation of the appropriate alkynyl halide, ill the method* previously used have been rather unsuitable for routine laboratory synthesis, end it was desirable to find a method whereby the acetylenie amines could be conveniently pre- pared using only equipment which would normally be found in an organic laboratory. In order to avoid the difficulty of preparing alkynes or alkynyl halides , it was decided to form a halo-alkenylamine which could then be dehydrohalogenated to the corresponding acetylenie amine. These halo- alkenylamines were easily prepared by the reaction of 2 ,3-dibromopropene with amines. Although these halo-alfcenylamines have not been previously reported in the literature, the reaction of a halogen compound with an 3 amine is so veil-known that a review of the literature on this subject it unnecessary. It would be impractical to repeat here the entire history of the process of dehydrohalogenatlon for the purpose of introducing a triple bond. An excellent surrey of previous research on the synthesis has been of acetylenes , including the process of dehydrohalogenatlon, published recently,*® and only a brief summary will be presented here. Alcoholic potassium hydroxide has bean used most frequently for the synthesis of acetylenes by dehydrohalogenatlon. Potassium hydroxide has also been widely used in solid or molten form. Sodium amide, sodium hydroxide, sodium ethoxlde, sodium anilide, sodium ethyl- mereaptide , potassium benzylate, potassium carbonate, potassium tort- butoxide, nethylemine, diethylamine , pyridine, quinoline, soda lime, and the alkaline earth carbonates and hydroxides hare also been used, although to a lesser extent. In the research described in this disserta- tion, only sodium amide was used for the dehydrohalogenatlon to produce a triple bond. Tor a more complete description of the use of other re- 10 agents, the reader le referred to the previously mentioned surrey. Meunler sad Despannet , who prepared acetylene by reacting ethylene bromide with powdered sodium amide, were the first to use this reagent to 11 produce a triple bond. In a later publication, they described the prep- 12 aratlon of some higher alkynes. Bourguel has published several papers describing the preparation of alkynes by dehydrohalogenatlon with sodium amide in an inert solvent such as toluene, xylene, or various high-boiling 4 petroleum fraction* . ^ *^**15 ,16 s^nce Bourguel** work, many investigator* have reported the use of sodium amide a* an agent for the introduction of a triple bond, ueually in high-bolllng, inert hydrocarbons a* the solvent. The first u*e of liquid -nroonia a* a solvent for the dehydro- halogenation reactions to produce a triple bond was reported by Vaughn, 1 Vogt, and Nisuwlaad. ^ The use of this solvent has since been reported 1 by Kyden, 01avis, and Marvel ® and by Campbell and 0* Connor. *9 Liquid eMaonta was need almost exclusively in the research described in this dissertation, since ite use resulted in better yields and in greater ease of purification of the products.
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