N-bromobutanimide → 5-Bromoindoline-6-carbonitrile

Reaction equation

[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[C:7]([C:10]#[N:11])[CH:8]=2)[CH2:3][CH2:2]1.C1C(=O)N([Br:19])C(=O)C1.C(=O)(O)[O-].[Na+]>CC#N>[Br:19][C:6]1[CH:5]=[C:4]2[C:9](=[CH:8][C:7]=1[C:10]#[N:11])[NH:1][CH2:2][CH2:3]2

Participants

Procedure

A solution of 2,3-dihydro-1H-indole-6-carbonitrile (2.5 g, 17.34 mmol) in MeCN (69 mL) was cooled to 0° C. and treated with NBS (3310 mg, 17.7 mmol). The light red reaction mixture was stirred at room temperature for 20 minutes, and was then poured into saturated aqueous sodium bicarbonate (200 mL). The product was extracted with ethyl acetate (2×200 mL), and the combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified using flash chromatography eluting with heptanes/ethyl acetate (95:5 to 60:40) to give the title compound (2.26 g, 58%) as a white solid. MS (ES−): 219.0, 221.0 (79Br M+H, 81Br M+H).