Acetic Acid → 1-Acetyl-5-bromo-3-(2-ethoxycarbonylethyl)-4,6-dimethyl-7-nitroindoline

Participants

Reaction Steps

To a mixture of AcOH (10 ml), conc. sulfuric acid (10 ml) and nitric acid (0.55 ml) was added by portions 1-acetyl-5-bromo-3-(2-ethoxy-carbonylethyl)-4,6-dimethylindoline (3.0 g) at 0° C., and the mixture was stirred at the same temperature for 5 hr. The reaction mixture was poured into ice water and extracted with CHCl3 (100 ml). After washing with water, the mixture was 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 2.7 g of 1-acetyl-5-bromo-3-(2-ethoxycarbonylethyl)-4,6-dimethyl-7-nitroindoline.

Provenance & Evidence