Reactions of some benzylidene compounds with potassium cyanide
Abstract
The o-, m-, and p-nitrobenzylidene derivatives of acetylacetone react with potassium cyanide to yield products of different types; respectively 3-acetyl-2-methylquinoline-4-carboxamide 1-oxide, the simple adduct, and 3-acetyl-5-amino-2-methyl-4-(4-nitrophenyl)furan. Various o-nitrobenzylidene compounds are attacked by cyanide ion with concomitant cyclisation to give derivatives of quinoline 1-oxide and/or 1-hydroxyindole. Easy hydrolysis of the introduced cyano-group to an amide function often occurs in the quinolinic but not in the indolic cyclisation. Related base-catalysed cyclisations are described for 2,3-bis-(2-nitrophenyl)propionitrile and 3,4-dibenzoyl-2-(2-nitrophenyl)butyronitrile. The unusual stability of the aldol which is obtained from o-nitrobenzaldehyde and cyclohexanone and the evidence of interaction between neighbouring ketonic and carbamoyl groups and ketonic and cyano-groups are noted.