Water → 5-bromo-3-formyl-1H-indole-6-carbonitrile

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (1.39 mL, 14.9 mmol) was added dropwise over 5 minutes to DMF (10 mL) with stirring. The clear mixture was stirred at room temperature for 10 minutes. A solution of 5-bromo-1H-indole-6-carbonitrile (1.10 g, 4.97 mmol) in DMF (1.5 with 0.5 mL wash) was added to the clear red solution, and the reaction mixture was stirred at room temperature for 5 min. The resulting grey suspension was heated to 80° C. under nitrogen for 25 min, and then allowed to cool to room temperature. The reaction mixture was treated slowly with water (30 mL) and aqueous 1 N NaOH (30 mL) at room temperature. The resulting thick suspension was then heated to 85° C. for five minutes with vigorous stirring. The reaction mixture was allowed to cool to room temperature over 5 minutes, and the solids were collected by filtration. The solids were dried in vacuo for 16 hours at 55° C. to afford the title compound (1.15 g, 92%) as a cream-colored solid. MS (ES−) 247.1 (M−H)−. 1H NMR (500 MHz, DMSO-d6) δ 12.76 (br. s., 1H), 9.99 (s, 1H), 8.60 (s, 1H), 8.43 (s, 1H), 8.18 (s, 1H).

Provenance & Evidence