A practical synthesis of para di- and mono-substituted benzhydrylamines from benzhydrol precursors

A series of para-substituted benzhydrylamines 6 were obtained by substitution of the corresponding benzhydrol precursors 1 with phenyl carbamate 2 under acidic conditions, followed by basic hydrolysis of the carbamate intermediates 3. One unsymmetrical intermediate 3i has been resolved by preparative chiral chromatography. Subsequent deprotection of the carbamate function led to the recovery of enantiomerically pure (+)- and (-)-4-chlorobenzhydryl amines.