Dat1;3: December 15, 1951 Name!: A. Merrill Schnitzer Position: Student Institution: Oklah<;itna A. & :M •. College Location: Stillwater, Oklahoma Title' of Study: The Reaction of 1,3,5-Trisubstituted Hexahydro-1,3,5- 1 t,riazines with Carbon Disulfide. Number of Pages in Study: 58 Under Direction of What Department: Chemistry. Scope of Study: The original purpose of the invest:Lgation was to determine 'whether N,N 1-disubstituted methylenediamines would react with carbon di­ sulfide and then with formaldehyde in a manner analogoµs to the corres­ ponding N,N'-disubstituted ethylenediamines. The ethylenediamines react with carbon disulfide to give the inner salts of N-alkyl-N-(,$-alkylamino­ ethyl)dithiocarbamic acids. These sal,ts, when treated with formaldehyde, react to form 3,6-disubstituted hexahydro-1,3,6-th;i.adiazepine-2-thiones. 'fhese seven-membered heterocyclic compounds may be the.rmally decomposed to l,J-disubstituted-2-imidazolidinethiones. The investigation was later shifted to the reaction of 1,3,5-trisub:Jtituted hexahydro-1,3,5-triazines with cnrbon disulfide, which produced compounds of the type sought. The pyroly$is of these reaction products was also studied. Find~ngs and· Conclusions: The N, f(' -disubstit uted methy lenes investigated did · not react in the manner expected. The methylenediamines used were aryl substituted, since the alkyl substituted homologs <;1.re not stable. Attempts to prepare N,N'-disubstituted methylenediamines resulted in the formation I of cyclic 1,3,5-t;dsubstituted hexa.hydro-1,3,5-triazines. It was found that i these compounds react w;ith carbon disulfide to produce 3, 5-disubstitvted · tetrahydra-1,3,5-thiadiazine-2-thiones. These latter substances were the compounds expected from the reaction of di.substituted methylenediamines with carbon disulfide,and formaldehyde. The homologs prepared are: ethyl, i isopropyl, cyclohe::i,cyl, /-phenylethyl, benzyl, phenyl, E-tolyl and £-phenetyl. This class of compounds has beep previously reported in the literature, but none of the homologs prepared, with the exception of the ethyl, is recorded. ·These substances were decomposed by pyrolysis and in the cases of the iso­ propyl, cyclohexyl, ,B ~phenylethyl, £-tolyl, and ,2-phenetyl homo logs, the products were 1,3,5-trisubstituted hexahydro-1,3,5-triazine-2-thiones. This , class of co!'.Ilpounds has not been reported in the literature. ADVISER'S THE REACTION OF l,3,5~TRISUBSTITUTED HEXAHYDR0-1,J,5-TRIAZINES WITH CARBON DISULFIDE THE REACTION: OF 1,3,5-TRISUBSTITUTEC HEXAHYI>RO-l,3,5""TRIAZIN.ES WITH CARBON DISULFIDE by A. MERRILL SCHNI~ER /I Master of Science Oklahoma Agricultural and Mechanical College Stillwater, Oklahoma 1949 Submitted to the Department ot Chemistry Oklahoma Agricultural and Mechanical College In Partial Fulfil'.l.ment of the Requirements for the Degree of DOCTOR .OF PHILOSOPHY 1951 OKUllOM~ ii AGRICULTUHL &. h'1ECnAHICAL cm LEGt LIBRARY MAY 1 1952 THE REACTION OF l,3,5-TRISUBSTITUTED rIEXAHYDR0- 1,3,5-TRlAZINES WITH CARBON DISULFIDE A~ MERRILL SCHNITZER MASTER OF SCIENCE 1949 THESIS AND ABSTRACT APPROVED: C/Thesis Adviser Dean ot the Graduate School Head ot the Department 291971 iii ACKNOWLEDGMENT The author wishes to express his sincere gratitude to Dro J. A. Shotton, under whose direction and guidance this work has been done, and to other members of the Department of Chendstr1 for their suggestions and helpful criticism, He also wishes to acknowledge the financial aid rendered by the Oklahoma A, and M, College in the form of a graduate fellowship in the Chemistry Department. iv TABLE OF CONTENTS Introductic;>n 1 Historical 2 Discussion 14 Experimental 33 Summary 55 Bibliography 56 1 INTRODUCTION The original purpose of this investigation was to determing whe ther N,N 1 -disubstitutedmethylenediamines would undergo reactions analogous t o those of the corresponding N,N 1-disubstitutedethylenediamines when treated with certain reagents. N,N'-dialkylethylenediamines react with carbon disulfide and formaldehyde to give heterocyclic compounds that are active vulcanization accelerators. Although some methylenediamines are stable enough to be isolated and kept for considerable periods, most of these compounds are unstable and tend to polymerize or decompose to give more stable compounds. The methylenediamines investigated did not give the desired reactions. It was found in the course of the investigation that the cyclic trimers of substituted methyleneimines (Azomethines, Schiff bases), the 1,3,5-trisubstitutedhexahydro-l,3,5-triazines, react with carbon di­ sulfide to give products of the type desired. A survey of the liter­ ature showed that this type of reaction has been mentioned only briefly. Several of these cyclic trimers were prepared and treated with carbon disulfide, and the reaction products, as well as the compounds resulting from their thermal decomposition, were investigated. 2 HISTORICAL The reaction of dialkylmonoamines and carbon disulfide has been widely studied, largely because the products are useful as vulcan- ization accelerators. The reaction produces the dialkylammonium salts of dialkyldithiocarbamic acids: R S ' N-C-SII - Rf These salts may be oxidized to thiuram disulfides: R, ~ ~ ,,R N-C-S-S-C-N R't 'R 1 In the presence of primary or secondary amines, the product may be dithiocarbamylsulfenamides (1): [o] R S R 11 ' N-v-S-N!l. / R" R) 'R" I '_.....NH R'" which may be thermally decomposed, losing an atom of sulfur, to yield tetrasubstituted thioureas. Donia, Shotton, Bentz, and Smith (2) found that, in general, the reactions of N,N'-dialkylethylenediamines with carbon disulfide are analogous to the reactions of the dialkylmonoamines. However, the ethylenediamines yield cyclic products, owing to the connection between the two nitrogen atoms. Hofmann (3) first reported the reaction of ethylenediamine with carbon disulfide to yield N-~-aminoethyl)dithiocarbamic acid (shown here in the dipolar ion form): 3 He thermally decomposed this acid and obtained hydrogen sulfide and 2-imidazolidinethione: which may be considered as a cyclic derivative of thiourea. Other investigators have extended these reactions to N- substituted- ethylenediamines. Donia, et al., (2) prepared a series of N-alkyl-N­ (,8-alkylaminoethyl)dithiocarbamic acid inner salts by the reaction of N,N'-dialkylethylenediamines with carbon disulfide. They found that these salts could be oxidized in alkaline solution with iodine-potassium iodide reagent to give 2,5-dialkyltetrahydro-1,2,5-thiadiazine-6-thiones: which may be considered to be cyclic dithiocarbamylsulfenamides. These compounds can be thermally decomposed, with the loss of sulfur, to the same 2-imidazolidinethiones as are obtained by decomposing the dithio- carbamic acid inner salts. It was found that the stability of the tetra- hydrothiadiazine ring is related to the size of the alkyl substituents attached to the nitrogen atoms. The isopropyl compound is less stable than the cyclohexyl compound, and the ethyl compound is quite unstable, being obtained only in low yields. Donia and co-workers (4) also studied the reactions of N,N'-dialkyl- diamines with carbon disulfide. These reactions were found to be analogous to those of the dialkylmonoamines, except that ring compounds were formed. These inves tigators prepared a series of 1,3-imidazolidines by condensation 4 of formaldehyde and other aldehydes with N,N'-dialkylethylenediamines. Treatment of the 1,3-dialkylimidazolidines with carbon disulfide in ether or alcohol results in the formation of J,6-dialkylhexahydro-l,J,6- thiadiazepine-2-thiones: These compounds are relatively unstable, and treatment with dilute ammonia water effects removal of the methylene group to form N-alkyl-N-(,6-alkyl­ aminoethyl)dithiocarbamic acid inner salts. They are decomposed also by heat or on standing at room temperature, with the splitting out of thio- formaldehyde and the formation of l,J-dialkyl-2-imidazolidinethiones. Delepine (5) treated the cyclic trimer of methylamine and formalde- hyde, l,3,5-trimethylhexahydro-1,3,5-triazine, with carbon disulfide and obtained a compound that he called 11 dimethylfci'rmocarbothialdine", m.p. 96°c., in the belief that it was an isomer of 11 carbothialdine". The compound long known as "carbothialdine" was first prepared through the action of carbon disulfide on acetaldehyde-ammonia by Redtenbacher and Liebig (6), and was thought to be related to the thialdines. The thialdines, which are 1,3,5-dithiazines, result from the action of hydrogen sulfide on aldehyde-ammonias. "Carbothialdine" was also prepared by Mulder (7) by condensing acetaldehyde with acrunoniwn dithiocarbamate or trithiocarbonate. This compound is thermally unstable, and the decomposition point has been reported as 120°·, by,·Cohn .(8.) and 1.35? by Ainley and co-workers. (9). It is difficult to purify, owing to rapid decomposition in solvents, including water and alcohols. It is soluble in dilute acids, though again with de­ composition. Claus (10) found that iodine, nitrous acid, or mercuric chloride also cause the compound to decompose, with the formation of ammonium thiocyanate, acetaldehyde, ammonia, and carbon disulfide. 5 Guareschi (11) found that ferric thiocyanate is formed when 11 car bothial- dine" is treated with ferric chloride; but that oxidation with ferric chloride in dilute acids, or with chlorine water, produces thiuram di- sulfide, indicating that the dithiocarbamate structure is present within the molecule. Mulder (7) and Levi and Gimignani (12) found that on treatment