The general procedure for the synthesis of 2-(2-bromophenyl)-4,6-diphenyl-1,3,5-triazine from benzenecarboxamidine hydrochloride and o-bromobenzaldehyde was as follows: a mixture of o-bromobenzaldehyde (6.8 mmol), benzenecarboxamidine hydrochloride (2 g, 11.4 mmol), Na2CO3 (1.21 g, 11.4 mmol, 1.0 equiv.) and Cu(OAc)2 (10 mol%) ) were stirred in toluene (20 mL) at 100°C and the reaction was carried out in air for 24 hours. Upon completion of the reaction, the mixture was cooled to room temperature. Water was added to the reaction system, followed by atmospheric pressure distillation until the toluene was completely evaporated. The resulting solution was filtered and the residue was washed three times with hot water. The crude product was purified by silica gel column chromatography using petroleum ether/EtOAc (100:1) as eluent to afford the target product 2-(2-bromophenyl)-4,6-diphenyl-1,3,5-triazine.
