反应详情

A mixture solution of 4-amino-3-chloro-benzoic acid methyl ester (21 g, 113.2 mmol), 3-bromo-benzaldehyde (21 g, 113.2 mmol) and p-toluenesulfonic acid (431 mg, 2.2 mmol) in toluene (200 mL) was heated to reflux for 12 hours. Then the reaction mixture was cooled to room temperature. The solvent was removed in vacuo and the residue was washed with ether to afford 4-[(3-bromo-benzylidene)-amino]-3-chloro-benzoic acid methyl ester (39.8 g, quant.) as a pale-white solid: MS calcd. for C18H11BrClNO2 353.62, obsd. (ESI+) [(M+H)+]351.9 & 353.9.

1. temperatureto reflux for 12 hours
2. customThe solvent was removed in vacuo
3. washthe residue was washed with ether