Dimethylformamide → 1-Cyano-4-hydroxy-7-phenoxy-isoquinoline-3-carboxylic acid butyl ester

Participants

Reaction Steps

A mixture of 1-bromo-4-hydroxy-7-phenoxy-isoquinoline-3-carboxylic acid butyl ester (624 mg, 1.5 mmol; prepared as shown in Scheme 2, and according to US 2004/0254215 A1, 1H NMR (CDCl3): δ=11.89 (s, 1H), 8.35 (d, 1H), 7.63 (d, 1H), 7.08 to 7.52 (m, 6H), 4.47 (t, 2H), 1.84 (m, 2H), 1.48 (m, 2H), 0.99 (t, 3H)), CuCN (271 mg, 3 mmol) and dimethylformamide (6 mL) was refluxed with stirring under nitrogen for 15 min. After cooling to ambient temperature the mixture was diluted with ethyl acetate (100 mL). The resulting suspension was filtered through a pad of celite. The filtrate was washed with water (2×250 mL), and dried over MgSO4 before silica gel was added. Subsequently, the mixture was concentrated in vacuo. The residue was added on top of a short column filled with silica gel. Elution with dichloromethane gave the title compound as a white solid (313 mg); MS-(−)-ion: M−1=361.2.

Provenance & Evidence