Phenylmagnesiumbromide and methylmagnesium bromide in tetrahydrofuran undergo a regioselective addition to the cyano group of the two title compounds. Phenyllithium and methyllithium add selectively to the azomethine portion of 2-[(benzylidene)amino]benzonitrile, but to the cyano group of 2-[(diphenylmethylene)amino]benzonitrile. These addition reactions are utilized in the synthesis of quinazoline