Nitric Acid → 5-Methoxy-1-methyl-4-nitroindole-2-carboxylic acid methyl ester

Participants

Reaction Steps

A solution of concentrated HNO3 (2 mL) in AcOH (9 mL) was added to a solution of 8 (830 mg, 3.79 mmol) in AcOH (54 mL) at 0° C. Following the addition, the reaction mixture was warmed to room temperature and stirred for 2 h. The reaction mixture was poured over ice, filtered and the precipitate washed with H2O. The precipitate was dissolved in CH2Cl2 and filtered through a short column of silica gel to afford 9 (780 mg, 78%) as a yellow solid; Rf=0.53 (50% EtOAc/hexanes); 1H NMR (CDCl3): δ 7.58 (1H, d), 7.55 (1H, s), 7.18 (1H, d), 4.11 (3H, s), 4.02 (3H, s), 3.94 (3H, s).

Provenance & Evidence