Synthesis of 4-propionyl-3-(4-substitutedphenylamino)- 2-(5-Nitropyridin-2-yl) isoxazol-5(2H)-ones and their Rearrangements to Imidazo [1,2- a] pyridines and Indoles with Triethylamine (TEA)

摘要

4-propionyl-3-(4-Substitutedphenylamino)isoxazol-5(2H)-ones, substituted on nitrogen with a 2-chloro-5-nitropyridine group, react with triethylamine (TEA) to give imidazo [1,2-a]pyridines and indoles. With 4-bromophenyl and 4-methylphenyl group substituents only imidazopyridines are formed, but the 4-methoxyphenyl derivative gave a 3:1 mixture of the corresponding imidazo[1,2-ajpyridine and 2-pyridylaminoindole, respectively.