Anil Synthesis in the Design of Push−Pull Systems. Synthesis of 2- and 4-(4-Styrylphenyl)-substituted Diphenylpyrimidines

The potential of anil synthesis for the preparation of 2,4,6-triaryl-substituted pyrimidines with an extended chain of delocalized π-bonds was studied. The reaction of ( E )-3-phenyl-1-( p -tolyl)prop-2-en-1-one or chalcone with benzamidine, 4-methylbenzamidine, or 4-isobutoxybenzamidine hydrochlorides in ethanol in the presence of KOH gave 2,4-diphenyl-6-( p -tolyl)pyrimidine, 4,6-diphenyl-2-( p -tolyl)pyrimidine, and 2-(4-isobutoxyphenyl)-4-phenyl-6-( p -tolyl)pyrimidine. The synthesized pyrimidines were reacted with ( E )- N -(phenyl- or 2-chlorophenyl)-1-arylmethanimines in DMF in the presence of a KOH/LiH mixture to obtain ( E )-4,6-diphenyl-2-(4-styrylphenyl)pyrimidines and ( E )-2,6-diphenyl-4-(4-styrylphenyl)pyrimidines were obtained.