Hydrochloric Acid → 5-methoxy-6-nitro-2,3-dihydro-1H-indole

Participants

Reaction Steps

To the solution of conc. HCl (20 mL) in methanol (40 mL) was added 1-acetyl-5-(methyloxy)-6-nitro-2,3-dihydro-1H-indole (7.8 g, 33 mmol) and the resulting mixture was refluxed for 4 hours. After cooling, the solvent was removed in vacuo, the residue was neutralized with saturated aqueous sodium hydrogencarbonate solution, and a brown precipitate formed. The precipitate was filtered via Buchner funnel, washed with water, and dried under reduced pressure to give 5-(methyloxy)-6-nitro-2,3-dihydro-1H-indole as a brown solid (6.1 g, 94% yield). 1H-NMR (DMSO, 300 MHz) δ 7.11 (s, 1H), 6.87 (s, 1H), 5.59 (brs, 1H), 3.78 (s, 3H), 3.43 (t, 2H), 2.97 (t, 2H).

Provenance & Evidence