Reactions of some nitrogen heterocycles with chlorodifluoromethane under conditions of phase-transfer catalysis

Aromatic heterocyclic compounds containing one to four nitrogen atoms react with chlorodifluoromethane in the presence of concentrated aqueous sodium hydroxide and a catalyst, benzyltriethylammonium chloride (TEBAC) in dichloromethane or THF (phase-transfer catalysis, PTC) with formation of N-difluoromethyl substituted derivatives. The process takes place by reaction of N-anions from these heterocycles with difluorocarbene and protonation of difluoromethyl anions thus formed.