Carbonyldiimidazole (40 mg) was added to a solution of 4-o-tolyloxyphenylamine (50 mg) in dimethylformamide (2 mL) at 0° C. After 30 minutes, (2,2-dimethoxyethyl)-[4-(2-dimethylaminoethoxy)phenyl]amine (67 mg) was added, and the mixture was heated at 80° C. for 2 hours. After cooling to room temperature, trifluoroacetic acid (0.5 mL) was added and the mixture was left to stand for 72 hours. The reaction solution was diluted with ethyl acetate and washed with saturated sodium bicarbonate solution. The organic phase was dried and concentrated. The residue was purified by preparative HPLC. The product with the molecular weight of 429.52 (C26H27N3O3); MS (ESI): 430 ([M+H]+), was obtained as hydrotrifluoroacetate in this way.
