N-bromobutanimide → 3-Bromo-7-chlorothieno[3,2-b]pyridine-6-carbonitrile

Participants

Reaction Steps

A mixture of 7-chlorothieno[3,2-b]pyridine-6-carbonitrile (100 mg, 0.51 mmol) and N-bromosuccinimide (118 mg, 0.66 mmol) in 0.63 mL of dimethylformamide is stirred at room temperature for 4 days. Additional N-bromosuccinimide (118 mgs) is added and the reaction mixture is heated at 40° C. for 17 hours. Additional N-bromosuccinimide (118 mgs) is added and the reaction mixture is heated at 40° C. for 24 hours. Additional N-bromosuccinimide (118 mgs) is added and the reaction mixture is heated at 60° C. for 24 hours. The mixture is cooled to room temperature and treated with ice water and neutralized with aqueous saturated sodium bicarbonate. The resultant solid is purified by flash column chromatography eluting with 10% hexane in dichloromethane to provide 35 mg of 3-bromo-7-chlorothieno[3,2-b]pyridine-6-carbonitrile as a white solid, mp 176–178° C.; 1H NMR (DMSO-d6) δ 8.79 (s, 1H), 9.23 (s, 1H); MS 272.9, 274.8.

Provenance & Evidence