1.60·2.20 (2H, m, —CH2 CH2O—), 1.99 (3H, S, -OCOCH3), 2.21 (3H, s, >NCOCH3), 2.38 (6H, s, —CH3×2), 3.40 (1H, m, Indoline C3—H), 4.11 (2H, t, J=7.0 Hz, —CH2 CH2O—), 4.14 (2H, d, J=8.5 Hz, Indoline C2—H). (4) 1-Acetyl-3-(2-acetoxyethyl)-5-bromo-4,6-dimethyl-7-nitroindoline (1.4 g) was dissolved in benzene (20 ml) and 5% Pd—C. (500 mg) was added, which was followed by catalytic hydrogenation at room temperature under A atmospheric pressure. Pd—C. was filtered off and benzene was evaporated under reduced pressure. The residue was dissolved in CHCl3 (50 ml) and the mixture was washed successively with saturated aqueous solution of sodium hydrogencarbonate and saturated brine, and dried over anhydrous sodium sulfate. Pivaloyl chloride (440 mg) and Et3N (448 mg) were added to the obtained solution and the mixture was stirred at room temperature for 30 min. The mixture was washed successively with 5% aqueous citric acid and saturated brine, and dried over anhydrous sodium sulfate. CHCl3 was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: CHCl3/MeOH=50/1−10/1) to give 1.0 g of N-[1-acetyl-3-(2-acetoxyethyl)-4,6-dimethylindolin-7-yl]-2,2-dimethylpropanamide.
