Synthesis and transformation of some thiourea derivatives

Reduction of a number of pyridylthiazolylketoximes gives amines, converted by p-ethoxyphenylisothiocyanate to the corresponding thioureas. It is shown that heating 3-pyridyl-,4-pyridyl-, and p-MeOC₆H₄-2-thiazolylmethylthiourea in dimethylformamide gives 7-substituted 5-mercaptoimidazo-[5,1-b]thiazoles, while heating substituted 2,4-dipyridylmethyl-and 2-pyridyl-2-tniazolylmethylthiourea gives 1-substituted 3-mercaptoimidazo[1,5-a]pyridines,