The reaction was carried out with 1-(5-methoxy-6-nitroindolin-1-yl)ethanone (Intermediate B98, 0.56 g, 2.37 mmol) as raw material, mixed with 10% Pd/C (500 mg) in ethanol (100 ml), and stirred under 1 atm hydrogen atmosphere. After completion of the reaction, the mixture was filtered through a diatomaceous earth pad and the filtrate was concentrated to dryness. The residue was dissolved in dichloromethane and purified by silica gel column chromatography using 30-60% ethyl acetate/dichloromethane as eluent to afford 1-acetyl-5-methoxy-2,3-dihydro-1H-indol-6-amine (Intermediate B127) as a white solid (327 mg, 67% yield). The product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 2.09 (s, 3H), 2.98 (t, J=8.33 Hz, 2H), 3.70 (s, 3H), 3.99 (t, J=8.33 Hz, 2H), 4.62 (s, 2H), 6.69 (s, 1H), 7.52 (s, 1H); ESIMS (M +H)+ m/z = 207.
