The Reactions of Hydrazine Derivatives with Carbon Disulfide

Abstract

The reactions of the free bases of aliphatic hydrazine derivatives with carbon disulfide were investigated in an aqueous sodium hydroxide solution. Aminoguanidine gave 2, 5-dimercapto1, 3, 4-thiadiazole (DMTD, 94%) and thiourea (50%). The result could be explained by the nucleophilic addition of the hydrazino group of aminoguanidine to carbon disulfide followed by the cleavage of the adduct into DMTD and cyanamide under the strong basic conditions. The latter was further converted to thiourea by the reaction with hydrogen sulfide. The reaction of other hydrazine derivatives such as thiosernicarbazide or semicarbazide gave DMTD under similar reaction conditions. The reaction of semicarbazide hydrochloride with carbon disulfide in pyridine at 45∼50°C for 4 h gave 1, 5-dicarbamoylthiocarbohydrazide (DCTH, 89%) via thermally unstable pyridinium semicarbazide-1-carbodithioate (PSDTC). When the reaction was stopped after 1 h, only intermediate PSDTC was isolated in 92% yield.