反应详情

A solution of 6-chloro-7-fluoroindole-2-carboxylic acid (2.1 g, 9.8 mmol) and diphenyl ether (30 mL) was heated under reflux for 4 h, cooled to room temperature and purified by column chromatography [SiO2; heptane-ethyl acetate (99:1 to 10:1)] to give the product (1.04 g, 63% yield) as a pale brown oil: IR νmax (Nujol)/cm−1 3460, 1573, 1490, 1446, 1201, 802 and 619; NMR δH (400 MHz, CDCl3) 6.44 (1H, brs) 7.04-7.09 (1H, m) 7.21-7.26 (1H, m) 7.30-7.34 (1H, m) and 8.40 (1H, brs).

1. temperatureunder reflux for 4 h
2. custompurified by column chromatography [SiO2; heptane-ethyl acetate (99:1 to 10:1)]