4-Nitro-1H-indole → HCID 57850033, compound

Participants

Reaction Steps

A stirred solution of 4-nitro-1H-indole (4a, 93.8 g, 0.56 mol) in DMF-MeOH (1:2, 2.7 L) cooled in a dry ice-acetone bath was bubbled with ozone (generated from oxygen gas, 22 g/m3, flow rate 500 L/hr, ozone generator: Tokyo Keiso, 11 g/hr) for 3.5 h. The mixture was kept cool in the dry ice-acetone bath for 1 h without stirring. The precipitate generated was filtered and washed with H2O to give N-(2-formyl-3-nitrophenyl)-formamide (5a, 62.0 g, 55%), 1H NMR (270 MHz) δ (DMSO-d6) 7.82 (t, J=7.9 Hz, 1H), 7.91 (d, J=7.9 Hz, 1H), 8.15 (m, 1H), 8.37 (br, 1H), 10.07 (s, 1H), 10.71 (br, 1H); MS (EI) m/z 194 (M+).

Provenance & Evidence