Water → 1-Bromo-4-hydroxy-isoquinoline-3-carboxylic acid butyl ester

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Reaction Conditions

Reaction Steps

2 g (7.7 mmol) of 1,4-Dihydroxy-isoquinoline-3-carboxylic acid butyl ester (from Example D-20b) dissolved in 100 ml of acetonitrile. 15.4 g (53.6 mmol) of phosphorous oxybromide added to solution and mixture stirred at 80° C. for 64 h. 100 ml of water was added to mixture, and mixture was removed from heat. Mixture was partitioned between ethyl acetate and water. Two phases were separated and the aqueous layer was extracted with ethyl acetate. Organic layers were combined, washed with brine, dried over magnesium sulfate, filtered, and evaporated. Residue was purified by silica gel flash chromatography to give 0.1 g (0.3 mmol) of product. 1H NMR (200 MHz, CDCl3) δ 11.89 (s, 1H), 8.41 (m, 1H), 8.25 (m, 1H), 7.84 (m, 2 H), 4.49 (t, J=7.0 Hz, 2H), 1.87 (m, 2H), 1.47 (m, 2H), 1.00 (t, J=7.2 Hz, 3H).

Provenance & Evidence