Indole → 3-iodo-1H-indole

Participants

Reaction Steps

To a stirred solution of indole 7 (1.0 eq.) in dimethylformamide (4.4 mL/mmol) under argon was added iodine (1.98 eq.) and potassium hydroxide (1.0 eq.). The reaction mixture was stiffed for 3 hours. The reaction mixture was quenched by addition of water (8.8 ml/mmol) and product precipitated, which was filtered and dried. The solid was resubmitted to reaction conditions (dimethylformamide (4.4 mL/mmol) under argon, iodine (0.4 eq.) and potassium hydroxide (0.2 eq.) and stiffed for 1 h) to convert the remaining starting material. The reaction mixture was quenched by addition of water (8.8 ml/mmol) and product precipitated, which was filtered and dried to afford 3-iodoindole 8. Beige solid. 1H NMR (d6-DMSO, 400 MHz) δ 1.39 (t, J=7.2 Hz, 3H), 4.40 (q, J=7.2 Hz, 2H), 7.35-7.42 (m, 2H), 12.66 (s, 1H), 19F NMR (d6-DMSO, 376 MHz) δ −126.87, MS (ESI−) m/z=366.13 (M−H)− 100%, 368.15 (M−H)− 35%.

Provenance & Evidence