Sodium difluoromethanesulfinate—A difluoromethylating agent toward protonated heterocyclic bases

Free radical difluoromethylation of protonated heteroaromatic bases was accomplished using sodium difluoromethanesulfinate in combination with tert-butyl hydroperoxide in a two-phase system (methylene chloride–water) at room temperature. The difluoromethylation products of methyl pyridine-4-carboxylate, pyridine-4-carbonitrile, and 2-amino-1,3,4-thiadiazole were isolated on a preparative scale.