Reaction of 1,3,5-trisubstituted hexahydro-1,3,5-1 triazines with carbon disulfide

Abstract

Scope of Study: The original purpose of the investigation was to determine whether N,N 1-disubstituted methylenediamines would react with carbon disulfide and then with formaldehyde in a manner analogous to the corresponding N,N'-disubstituted ethylenediamines. The ethylenediamines react with carbon disulfide to give the inner salts of N-alkyl-N-(?-alkylamino-ethyl) dithiocarbamic acids. These salts, when treated with formaldehyde, react to form 3,6-disubstituted hexahydro-1,3,6-thiadiazepine-2-thiones. These seven-membered heterocyclic compounds may be thermally decomposed to 1,3-disubstituted-2-imidazolidinethiones. The investigation was later shifted to the reaction of 1,3,5-trisubstituted hexahydro-1,3,5-triazines with carbon disulfide, which produced compounds of the type sought. The pyrolysis of these reaction products was also studied.

Findings and Conclusions: The N,N'-disubstituted methylenes investigated did not react in the manner expected. The methylenediamines used were aryl substituted, since the alkyl substituted homologs are not stable. Attempts to prepare N,N'-disubstituted methylenediamines resulted in the formation of cyclic 1,3,5-trisubstituted hexahydro-1,3,5-triazines. It was found that these compounds react with carbon disulfide to produce 3, 5-disubstituted tetrahydra-1,3,5-thiadiazine-2-thiones. These latter substances were the compounds expected from the reaction of disubstituted methylenediamines with carbon disulfide and formaldehyde. The homologs prepared are: ethyl, isopropyl, cyclohexyl , ?-phenylethyl, benzyl, phenyl, p-tolyl and p-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 isopropyl, cyclohexyl, ?phenylethyl, p-tolyl, and p-phenetyl homo logs, the products were 1,3,5-trisubstituted hexahydro-1,3,5-triazine-2-thiones. This class of compounds has not been reported in the literature.