WEBThiazole, or 1,3-thiazole, is a 5-membered heterocyclic compound that contains both sulfur and nitrogen. The term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine -like odor and the molecular formula C 3 H 3 NS. [2] The thiazole ring is notable as a component of the vitamin ...