Pyrrolo[2 ',3 ': 4,5]furo[3,2-c]pyridine derivatives reactions in the pyridine and pyrrole ring

Methyl 1-methylpyrrolo[2',3':4,5]furo[3,2-c]pyridine-2-carboxylate was oxid ized with m-chloroperbenzoic acid in dichloromethane to 2-methoxycarbony-1- methylpyrrolo[2',3':4,5]furo[3,2-c]pyridine-7-oxide. Treatment of this comp ound with benzoyl chloride and cyanide anion (Reissert-Henze reaction) was shown to produce the corresponding methyl 8-cyano-1-methylpyrrolo[2',3':4,5 ]furo[3,2-c]pyridine-2-carboxylate. Methyl 1H-pyrrolo[2',3':4,5]furo[3,2-c] pyridine-2-carboxylate was prepared by reduction of methyl 8-chloro-1H-pyrr olo[2',3':4,5]furo[3,2-c]pyridine-2-carboxylate with hydrazine and palladiu m on carbon. Both esters with hydrazine hydrate yielded the corresponding c arbohydrazides, which by reaction with orthoesters afforded 4-substituted 2 H-pyrido [3",4":4',5']furo[2',3':4,5]pyrrolo[1,2-d][1,2,4]triazin-1-ones.