Phosphorus oxychloride → 1,3-dimethyl-1H-indole-2-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

Phosphorous oxychloride (0.0.93 mL, 9.7 mmol) was added dropwise with stirring to DMF (5 mL) at 10° C. over 20 min. 1,3-dimethyl-1H indole (1.3 g mg, 8.9 mmol) in DMF (5 mL) was added slowly with stirring and the mixture was heated for 3 h at 98-100° C. Excess concentrated aqueous solution of sodium acetate was added. The mixture was stirred for 30 min at 28° C. and extracted with ethyl acetate, dried and evaporated. The crude mixture was chromatographed over silica gel eluting with hexane/ether to afford the title compound (1.5 g, 97%). 1H NMR (400 MHz, DMSO-d6) δ 10.15 (s, 1H), 7.74 (d, J=7.6 Hz, 1H), 7.53 (d, J=7.8 Hz, 1H), 7.42 (t, J=8.0 Hz, 1H), 7.15 (t, J=7.6 Hz, 1H), 3.99 (s, 3H), 2.60 (s, 3H)

Provenance & Evidence