Iodine → methyl 3-iodo-1H-indole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

A brown solution of I2 (3.98 g, 15.70 mmol) in DMF (4.0 mL) was added dropwise over 5 min to a yellow-brown suspension of methyl 1H-indole-5-carboxylate (Aldrich, St. Louis, Mo.; 2.5 g, 14.27 mmol) and potassium carbonate (3.96 g, 28.7 mmol) in DMF (14.0 mL), and the resulting mixture was stirred at 25° C. for 16 h. The mixture was added to a mixture of ice (10 g), H2O (200 mL), and sodium bisulfite (2.228 g, 21.41 mmol). The resulting mixture was extracted with DCM (2×200 mL), and the combined organic extracts were dried over sodium sulfate, filtered, and concentrated in vacuo to provide methyl 3-iodo-1H-indole-5-carboxylate (3.87 g, 12.85 mmol, 90%) as a brown solid: MS (ESI, pos. ion) m/z: 301.9 (M+1). 1H NMR (400 MHz, CDCl3) δ ppm 8.22 (s, 1H), 8.00-8.03 (m, 1H), 7.96 (dd, J=8.6, 1.4 Hz, 1H), 7.39 (d, J=8.8 Hz, 1H), 7.37 (d, J=2.3 Hz, 1H), 3.96 (s, 3H).

Provenance & Evidence