反应详情

A solution of 3-bromo-5-trifluoromethoxybenzaldehyde (20, 2.00 g, 7.43 mmol), ethylene glycol (2.31 g, 37.2 mmol), para-toluenesulfonic acid (50 mg, 0.26 mmol) in anhydrous toluene (50 mL) was refluxed using a Dean-Stark apparatus for 3 h. The solution was concentrated and the product purified by silica gel chromatography eluting with 0-10% EtOAc in hexanes to afford the title compound (1.25 g, 54%) as a clear, colorless oil: 1H NMR (500 MHz, CDCl3) δ 7.57 (t, J=1.5 Hz, 1H), 7.37 (s, 1H), 7.28 (s, 1H), 5.79 (s, 1H), 4.12-4.01 (m, 4H).

1. customfor 3 h
2. concentrationThe solution was concentrated
3. customthe product purified by silica gel chromatography
4. washeluting with 0-10% EtOAc in hexanes