Synthesis of Novel Thiazole and Pyrrolothiadiazine Derivatives from Aldehyde Thiosemicarbazones

Substituted thiosemicarbazones 7a–e reacted with ethenetetracarbonitrile (TCNE) in ethyl acetate with formation of 5-amino-3-(substituted ben-zylidene-amino)-2-phenylimino-2,3-dihydrothiazole-4-carbonitrile 8a–e 2-amino-6-phenyl-imino-1,6- dihydropyrrolo[1,3,4]thiadiazine-3-carbonitrile 9, and phenyl-(5-{substituted phenyl}-3H-[1,3,4]thiadiazole-2-ylidene)amines 10a–e. Rationales for the observed conversations are presented. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:261–266, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20198