反应详情

A solution of 4-fluoro-7-methoxy-1-benzothiophene-2-carboxamide (0.756 g, 3.3 mmol) in phosphorus oxychloride (6.2 mL, 6.6 mmol) was refluxed for 3 h then cooled and the solvent evaporated in vacuo to give the title compound. Purified by flash chromatography with a gradient of 0–30% ethyl acetate in iso-hexane to give a colourless solid (0.635 g, 91%); δH (300 MHz, CDCl3) 7.95 (1H, s, 3-ArH), 7.10–7.01 (1H, m, ArH), 6.85–6.77 (1H, m, ArH) and 3.98 (3H, s, OCH3).

1. temperaturethen cooled
2. customthe solvent evaporated in vacuo