Carboxamide–pyridine N-oxide heterosynthon for crystal engineering and pharmaceutical cocrystals

Abstract

The novel carboxamide-pyridine N-oxide synthon, sustained via N-H...O- hydrogen bonding and C-H...O interaction, is shown to assemble isonicotinamide N-oxide in a triple helix architecture and the same heterosynthon is exploited to synthesize cocrystals of barbiturate drugs with 4,4'-bipyridine N,N'-dioxide.