反应详情

A mixture of 4-bromo-2-fluorobenzaldehyde (5.00 g, 24.6 mmol), p-toluenesulfonic acid monohydrate (190 mg, 1.00 mmol) and ethylene glycol (10 mL) were refluxed in benzene (50 mL) and EtOH (10 mL) under a Dean-Stark trap for 3 h. The reaction mixture was cooled and poured into a mixture of 5% aqueous NaHCO3 (100 mL) and ice (100 mL). The mixture was extracted with ether (3×150 mL), and the combined ethereal extracts were washed with brine (200 mL) and dried (MgSO4). Concentration under reduced pressure afforded 6.02 g (99%) of 88 that was used without further purification. 1H NMR (400 MHz, CDCl3): δ 4.01-4.14 (m, 4H), 6.02 (s, 1H), 7.24-7.31 (m, 2H), 7.41 (t, J=7.9 Hz, 1H).

1. temperatureThe reaction mixture was cooled
2. extractionThe mixture was extracted with ether (3×150 mL)
3. washthe combined ethereal extracts were washed with brine (200 mL)
4. dry with materialdried (MgSO4)
5. concentrationConcentration under reduced pressure