Dimethylformamide → methyl 6-bromo-3-formyl-1-isopropyl-1H-indole-4-carboxylate

Participants

Reaction Steps

To a stirred solution of DMF (1.04 lit) POCl3 (40.3 g, 263 mmol) was added at 0° C. and stirred for 20 min. Then methyl 6-bromo-1-isopropyl-1H-indole-4-carboxylate (65 g, 2119.5 mmol) in DMF (260 mL) was added to the reaction mixture at 0° C. The reaction mixture was stirred at room temperature for 3 h. Diluted the reaction mixture with cold water and adjusted PH˜8 using with 2N NaOH solution, extracted with ethylacetate (4×1 lit). The organic layer washed with cold water, brine solution, dried over anhydrous Na2SO4 and concentrated under reduced pressure to afford desired product methyl 6-bromo-3-formyl-1-isopropyl-1H-indole-4-carboxylate (65 g, 91.3%). 1H NMR (CDCl3, 400 MHz): δ 1.588 (d, 6H, J=6.8 Hz), 3.994 (s, 3H), 4.634-4.701 (m, 1H), 7.760 (d, 1H, J=1.6 Hz), 7.958 (d, 1H, J=1.6 Hz), 8.122 (s, 1H), 10.446 (s, 1H). LC-MS (ES+) m/z=324.02 (M+H)

Provenance & Evidence