Synthesis of Derivatives of 8-Cyano-6-ethoxycarbonyl-3-hydroxy-5-methylimidazo[1,2-a]pyridine and 9-Alkoxycarbonyl- (or 9-Carboxy)-3-ethoxycarbonyl-2-methyl-10H-benzo[b]-1,8-naphthyridine-5-one from the Reaction of 2-Chloro-5-ethoxycarbonyl-6-methyln

摘要

2-Substituted 8-cyano-6-ethoxycarbonyl-3-hydroxy-5-methylimidazo[1,2-a]pyridine was formed from the interaction of 2-chloro-5-ethoxycarbonyl-6-methylnicotinonitrile with α-amino acids in DMF. The same nitrile on boiling with anthranilic acid or its esters in butanol gave, respectively, 2-(2-carboxyanilino)- or 2-(2-alkoxycarbonylanilino)-5-ethoxycarbonyl-6-methylnicotinonitriles which cyclized on heating in PPA to give 9-alkoxycarbonyl(or 9-carboxy)-3-ethoxycarbonyl-2-methyl-10H-benzo[b]-1,8-naphthyridin-5-ones.