Synthesis of 5-Azolyl-2,4-dihydro-3h-1,2,4-triazole-3-thiones and 5-Azolyl-1,3,4-thiadiazol-2-amines Based on Derivatives of 5-Arylisoxazole-3-carboxylic and 4,5-Dichloroisothiazole-3-carboxylic Acids

2-Mercapto-1,3,4-triazoles and 2-amino-1,3,4-thiadiazoles were synthesized by successive transformations of 5-arylisoxazole- and 4,5-dichloroisothiazole-3-carboxylic acids and their derivatives. The amino group of 5-(4,5-dichloroisothiazol-3-yl)-1,3,4-thiadiazol-2-amine was acylated with 5-phenylisoxazole-3-carboxylic acid chloride. Simple approaches to the preparation of previously unknown heterocyclic assemblies containing two or three azole rings with a high potential for biological activity are described.