Novel thiazoles 3a- g, 4 ad are synthesized from N-cyanoimidates and 3-cyanoisoureas of type la-m and thioglycolic acid methyl ester (2a) as well as the amide (2b). The limitations of the reaction are outlined. The products are further converted into thiazolo [4, 5-dlpyrimidines 6a-d and thiazolo [4, 5-dJ-1, 2, 3-triazinones 7a-c.