AUTRE VOIE D'ACCES AUX 5H-PYRIDOPYRROLOPYRIDINES ET LEUR TRANSFORMATION EN DERIVES N-5 ET N-8 SUBSTITUES

Article abstract of DOI:10.1016/S0040-4020(01)90610-6

4-hydrazino-1H-pyridin-2-ones obtained starting from corresponding 2,4-dihydroxypiridines react with N-acetyl 4-piperidone.The expected hydrazones then give 6,7,8,9-tetrahydro 8-acetyl-2H,5H-pyrido<3'4':4,5>pyrrolo<3,2-c>pyridin-1-ones by thermal Fischer indole reaction.Aromatization of these last compounds with 10 percent palladized charchoal gives 2H,5H-pyrido<3',4':4,5>pyrrolo<3,2-c>pyridin-1-ones providing a new reaction pathway to this series which is more convenient that the one described in the preceding paper.Whereas the alkylation of the N-matallated species derived from 1-chloro-4-methyl-5H-pyrido<3',4':4,5>pyrrolo<3,2-c>pyridine by alkyl halides leads to the mixture of N-5 and N-8 alkyl derivatives, 1-chloro-5H-pyrido<3',4':4,5>pyrrolo<3,2-c>pyridine gives only the N-5 alkylated compound.