To a solution of 4-phenylsulfonylamino-3-aminobenzotrifluoride (100 mg; prepared in Reference Example 26) and terephthal aldehyde acid methyl ester (78 mg) in MeOH (2 ml), acetic acid (1.5 ml) was added. The mixture was stirred for 2 hours at room temperature. After stirring, a solution of sodium cyanoborohydride (30 mg) in MeOH (2 ml) was added. The mixture was stirred for 2 hours at room temperature. The reaction solution was extracted with H2O-AcOEt, washed, dried over, filtered and concentrated. The precipitate was washed with hexane to give the title compound (146 mg) having the following physical data.
