[Synthesis]
The general procedure for the synthesis of N-[6-(2-aminophenylamino)-6-oxohexyl]-4-methylbenzamide (R01) from o-phenylenediamine and 6-(4-methylbenzoylamino)hexanoic acid was as follows: under nitrogen protection, 6-(4-methylbenzoylamino)hexanoic acid (498 mg, 2 mmol), o-phenylenediamine (216 mg, 2 mmol), EDCI (383 mg, 2 mmol), HOBt (405 mg, 3 mmol) and triethylamine (404 mg, 4 mmol) were dissolved in dichloromethane (30 mL) and the reaction was stirred at room temperature. After completion of the reaction, the reaction mixture was washed with water and brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford the target compound N-[6-(2-aminophenylamino)-6-oxohexyl]-4-methylbenzamide (227 mg, 33.9% yield) as a white solid. The product was confirmed to be >95% pure by 1H NMR (DMSO-d6) and LC-MS characterization.1H NMR (DMSO-d6) δ: 9.06 (s, 1H), 8.35 (s, 1H), 7.73 (d, J = 8.0 Hz, 2H), 7.24 (d, J = 8.0 Hz, 2H), 7.14 (t, J = 7.5 Hz, 1H), 6.86-6.89 (m, 1H), 6.70 (d, J = 7.5 Hz, 1H), 6.50 (t, J = 7.5 Hz, 1H), 4.80 (s, 2H), 3.22-3.26 (m, 2H), 2.30-2.35 (m, 5H), 1.53-1.65 (m, 4H), 1.36-1.38 (m, 2H). LC-MS (ESI): m/z 340 [M+H]+. |