反应详情

A mixture of 5,7-dichloro-8-benzyloxy-quinoline-2-carboxylic acid 18 (2.56 g, 7.35 mmol) and concentrated hydrochloric acid (25 mL) was stirred at RT for 48 h, and then concentrated to dryness. The resulting residue was washed with diethyl ether (20 mL×2). This provided 5,7-dichloro-8-hydroxyquinoline-2-carboxylic acid 19 as a yellow solid (1.78 g, 94%). 1H NMR (CDCl3/DMSO-d6 (19:1), 400 MHz): δ 10.60 (br, 1 H), 8.53 (d, J=8.8, 1 H), 8.22 (d, J=8.8, 1 H), 7.60 (s, 1 H).

1. concentrationconcentrated to dryness
2. washThe resulting residue was washed with diethyl ether (20 mL×2)