Ring-Ring Interconversions. Part 3[1]. On the Effect of the Substituents on he Thiazole Moiety in the Ring-Opening/Rings-Closing Reactions of Nitrosoimidazo[2,1-b][1,3]thiazoles with Hydrochloric Acid

摘要

The reaction of 6-(4-chlorophenyl)-5-nitrooimidazo[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 effecxt of substituents on the thiazole ring in a reacently reported ring-ring interconversion reaction. In every case the corresponding[1,4]-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-3 have been obtained. In particular, the benzolderivative f19 furnished the 4-(4-chlorophenyl)-4-hydroxy-4H-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.