Hydrochloric Acid → 3-iodo-1-tosyl-1H-indole-5-carboxylic acid

Participants

Reaction Steps

A solution of 3-iodo-1H-indole-5-carboxylic acid (3.70 g, 12.89 mmol) in DMF (9.5 mL) at 0° C. was treated with NaH (60% in mineral oil) (1.289 g, 32.2 mmol). After 15 min at 0° C., p-toluenesulfonyl chloride (2.95 g, 15.47 mmol) was added in 1 g portions at 0° C. every 15 min and the reaction was warmed slowly in the ice bath to 10° C. After 2 h, the mixture was dumped into H2O and the mixture was acidified with 5 M HCl. The precipitate was collected by filtration, washed with water and dried to afford crude 3-iodo-1-tosyl-1H-indole-5-carboxylic acid (5.72 g) as a tan solid. MS (ESI, pos. ion) m/z: 442 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 8.20 (1H, s), 8.03-8.09 (1H, m), 7.93-8.02 (3H, m), 7.91 (1H, s), 7.42 (2H, d, J=8.0 Hz), 2.33 (3H, s)

Provenance & Evidence