チアツオール誘導体の研究 (第14報)

Abstract

Decomposition of the hydrochloride of bis (2-thiazolyl) sulfide compounds by heating in carbon disulfide is affected by the substituent in 5-position of the thiazole ring. While CH3 and CH2CH2OH have no effect on the 2-position, COOC2H5 group in 5-position results in selective formation of ethyl 2-chloro-4-methyl-5-thiazolecarboxylate (IX), and this was proved by reaction between bis (2-thiazolyl) sulfide hydrochloride (or hydrobromide) and 2-chlorothiazole derivatives. The reason for formation of two kinds of symmetric bis (2-thiazolyl) sulfides by reaction of ethyl 2-mercapto-4-methyl-5-thiazolecarboxylate (VIII) and 2-chlorothiazole derivatives, 2-mercapto-4, 5-dimethylthiazole (XIV) and 2-(2-chloro-4-methyl-5-thiazolyl) ethanol (IV), or 2-(2-mercapto-4-methyl-5-thiazolyl) ethanol (I) and 2-chloro-4, 5-dimethylthiazole (XV), during syntheses of non-symmetric bis (2-thiazolyl) sulfide compounds, was assumed to be due to the similar decomposition reaction of an intermediary produced hydrochloride and subsequent reaction of the decomposition products or starting materials with each other to fix hydrochloric acid or to form bis (4-methyl-5-ethoxycarbonyl-2-thiazolyl) sulfide (X) which does not form a hydrochloride.