Sodium Hydroxide → 6-Chloro-2,3-dihydro-1h-indole

Participants

Reaction Steps

6-Chloroindole (1 g, 6.6 mmol) in glacial acetic acid (10 mL) was treated with sodium cyanoborohydride (829 mg, 13.2 mmol) portionwise at room temperature with stirring. After 1 hour, the reaction was diluted with water (25 mL) and basified with 40% sodium hydroxide with cooling. The mixture was then extracted with dichloromethane (3×50 mL), dried and concentrated to give 1 g of 6-chloroindoline. It was used in the next step without further purification. 1HNMR (300 MHz, dimethylsulfoxide-d6) δ 6.95 (d, 1H), 6.46 (dd, 1H), 6.43 (d, 1H), 5.74 (br s, 1H, NH), 3.42 (t, 2H, CH2), 2.85 (t, 2H, CH2). MS m/z 349 [M+1].

Provenance & Evidence