Dimethylformamide → HCID 86672719, compound

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (7.74 ml, 84.6 mmol) was added slowly to ice-cold DMF (200 mL) and the resulting mixture was stirred at 0° C. for 1 h. To this mixture was added a solution of methyl 1-(4-methoxybenzyl)-1H-indole-4-carboxylate (16.6 g, 56.4 mmol) from Step A above in DMF (100 mL) and the mixture was stirred for 2 h. The reaction mixture was poured into an ice/water mixture and the pH was adjusted to 7 by adding 1 N NaOH. The compound was extracted with ethyl acetate (3×500 mL) and the combined organic layers were washed with water (4×250 mL) and brine (4×250 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The crude material was purified by silica gel chromatography (ethyl acetate/hexanes: 20-40%) to afford methyl 3-formyl-1-(4-methoxybenzyl)-1H-indole-4-carboxylate (16.7 g, 93%) as an off-white solid: 1H NMR (500 MHz, CDCl3) δ 10.48, (s, 1H), 7.99 (s, 1H), 7.85 (dd, J=10.0, 5.0 Hz, 1H), 7.55 (dd, J=10.0, 5.0 Hz, 1H), 7.30 (t, J=10.0 Hz, 1H), 7.12 (d, J=10.0 Hz, 2H), 6.86 (d, J=10.0 Hz, 2H), 5.31 (s, 2H), 3.99 (s, 3H), 3.71 (s, 3H); MS (ESI+) m/z 324 (M+H).

Provenance & Evidence