Preparation of Primary Amines by the Alkylation of O-Sulfonyloximes of Benzophenone Derivatives with Grignard Reagents

Primary amines are prepared by the electrophilic amination of Grignard reagents with benzophenone O-sulfonyloxime derivatives. 4,4′-Bis(trifluoromethyl)benzophenone O-sulfonyloximes react with alkyl Grignard reagents in the presence of a catalytic amount of CuCN in tetrahydrofuran-hexamethylphosphoric triamide to give N-alkylimines, which are readily hydrolyzed to primary amines. 3,3′,5,5′-Tetrakis(trifluoromethyl)benzophenone O-p-tolylsulfonyloxime is arylated to the corresponding N-arylimines with aryl Grignard reagents in ether–toluene, and hydrolysis of the resulting imines gives aniline derivatives.