Ring-ring interconversions. Part 3. On the effect of the substituents on the thiazole moiety in the ring-opening/ring-closing reactions of nitrosoimidazo[2,1-b][1,3]thiazoles with hydrochloric acid

✍ Scribed by Roberta Billi; Barbara Cosimelli; Domenico Spinelli; Alberto Leoni

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2000
• Tongue: English
• Weight: 297 KB
• Volume: 37
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570370433

✦ Synopsis

Abstract

The reaction of 6‐(4‐chlorophenyl)‐5‐nitrosoimidazo[2,1‐b][1,3]thiazole 1b, 6‐(4‐chlorophenyl)‐2‐methyl‐5‐nitrosoimidazo[2,1‐b][1,3]thiazole 1c, 6‐(4‐chlorophenyl)‐2,3‐dimethyl‐5‐nitrosoimidazo‐[2,1‐b][1,3]thiazole 1d and 2‐(4‐chlorophenyl)‐3‐nitrosobenzo[d]imidazo[2,1‐b][1,3]thiazole 1e with hydrochloric acid has been carried out in order to investigate the effect of substituents on the thiazole ring in a recently reported ring‐ring interconversion reaction. In every case the corresponding [1,4]‐thiazino[3,4‐c][1,2,4]oxadiazol‐3‐ones 2b‐e have been obtained. In particular, the benzoderivative 1e furnished the 4‐(4‐chlorophenyl)‐4‐hydroxy‐4__H__‐benzo[5,6][1,4]thiazino[3,4‐c][1,2,4]oxadiazol‐1‐one 2e, containing a new tricyclic system with a quasi‐planar geometry whose pharmacological potentialities appear promising.