反应详情

A mixture of 4-hydroxy-3-methyl-benzaldehyde (7.0 g, 51.4 mmol), K2CO3 (21.32 g, 154.2 mmol) and 2-bromoethyl acetate (25.8 g, 154.2 mmol) in acetone (250 mL) is refluxed for 18 h before it is diluted with diethyl ether (300 mL) and washed with water (3×250 mL). The washings are extracted with diethyl ether (200 mL). The combined organic extracts are dried over MgSO4 and concentrated. The remaining residue is purified by column chromatography on silica gel eluting with heptane/EA 1:1 to afford the title compound (11.14 g) as colourless solid. 1H NMR (CDCl3):δ 9.85 (s, 1H), 7.72-7.67 (m, 2H), 6.92-6.88 (m, 1H), 4.51-4.46 (m, 2H), 4.29-4.25 (m, 2H), 2.27 (s, 3H), 2.11 (s, 3H).

1. temperatureis refluxed for 18 h before it
2. washwashed with water (3×250 mL)
3. extractionThe washings are extracted with diethyl ether (200 mL)
4. dry with materialThe combined organic extracts are dried over MgSO4
5. concentrationconcentrated
6. customThe remaining residue is purified by column chromatography on silica gel eluting with heptane/EA 1:1