Step A: 2-amino-3-methylbenzoic acid (4.0 g, 26.5 mmol) was dissolved in degassed DMF (40 mL) under nitrogen protection. HOBt (4.28 g, 31.7 mmol), DIEA (5.52 mL, 31.7 mmol) and 2N NH3/MeOH solution (19 mL, 37.1 mmol) were added sequentially. The reaction mixture was stirred at room temperature for 16 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure, and the crude product obtained was purified by silica gel column chromatography with an eluent of 10-60% EtOAc/hexane mixed solvent, resulting in 2-amino-3-methylbenzamide (2.52 g, 63% yield) as a white solid. The structure of the product was confirmed by 1H NMR (300 MHz, DMSO-d6): δ 2.07 (s, 3H), 6.40-6.47 (m, 3H), 7.06 (m, 2H), 7.42 (d, 1H), 7.72 (br d, 1H).
