反应详情

A mixture of 3-hydroxy-4-ethoxybenzaldehyde (0.413 g, 2.5 mmol), 3,5-dimethoxyacetophenone (0.448 mg, 2.5 mmol) and 50% w/v of aqueous sodium hydroxide (3.98 ml, 0.049 mol) in methanol (5 ml) at room temperature for 18 h. The yellow solid that precipitated was filtered and sequentially washed with cold methanol and ether and finally dried in a vacuum dessicator. Purification by column chromatography (SiO2, petroleum:ether (40:60 v/v) with an increasing gradient of ethyl acetate) yielded 0.29 g (36%) of a yellow solid. 1H-NMR (CDCl3) δ 7.7 (d, 1H), 7.2 (m, 2H), 7.1 (d, 3H), 6.8 (d, 1H), 6.5 (t, 1H), 5.7 (s, 1H), 4.1 (q, 2H), 3.9 (s, 6H), 1.4 (t, 3H). 13C-NMR (CDCl3) δ 190.1, 160.9, 148.2, 146.1, 144.9, 140.6, 128.5, 122.7, 120.3, 113.1, 111.4, 106.3, 105.0, 64.7, 55.7, 14.8. Mass Spectrum m/e (M+1) 329. Anal. Calcd. for C19H20O5.0.5H2O: C, 69.5; H, 6.14. Found C, 69.62; H, 6.16.

1. filtrationThe yellow solid that precipitated was filtered
2. washsequentially washed with cold methanol and ether
3. customfinally dried in a vacuum dessicator
4. customPurification by column chromatography (SiO2, petroleum:ether (40:60 v/v) with an increasing gradient of ethyl acetate)