Studies on Pyrimidine Derivatives and Related Compounds. LXV. On the Reactions of Thiamine with Carbon Disulfide

Abstract

The action of CS₂ on B₁-HCl in MeOH after treatment with Et₃N gave B₁-methyl-xanthogenate (II). This reaction was applied to potassium xanthogenate as a new B₁ precipitant. The reaction of II with primary amines gave thioureas, while the reaction with secondary amines yielded corresponding 2-methyl-4-amino-5-pyrimidinylmethylcarbodithioates by exchange with thiazole moiety of B₁. This substitution reaction was found to be caused by the reaction between B₁ and aminocarbodithioate. On the other hand, the reaction of CS₂ with B₁-Na salt followed by the action of alkyl halides afforded the S-dithioalkoxycarbonylthiamines readily.