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

Beteiligte Stoffe

Reaktionsschritte

A mixture of 1-bromo-4-hydroxy-isoquinoline-3-carboxylic acid butyl ester (1.621 g, 5 mmol; prepared as shown in Scheme 2, according to US 2004/0254215 A1; 1H NMR (200 MHz, CD3OD) δ 11.89 (s, 1H), 8.41 (m, 1H), 8.25 (m, 1H), 7.84 (m, 2H), 4.49 (t, J=7.0 Hz, 2H), 1.87 (m, 2H), 1.47 (m, 2H), 1.00 (t, J=7.2 Hz, 3H)), CuCN (905 mg, 10 mmol) and dimethylformamide (20 mL) was refluxed with stirring under nitrogen for 5 min. After cooling to ambient temperature the mixture was diluted with water (300 mL). Then ethyl acetate (150 mL) was added and the mixture was shaken thoroughly for 5 min before it was filtered through a pad of celite. The organic phase of the filtrate was separated, and dried over MgSO4 before silica gel was added. 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 yellowish solid (627 mg); MS-(−)-ion: M−1=269.2.

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