反应详情

A mixture of 3-hydroxy-4-propoxybenzaldehyde (0.4 g, 2.1 mmol), 3,5-dimethoxyacetophenone (0.371 mg, 2.1 mmol) and 50% w/v of aqueous sodium hydroxide (3.3 ml, 0.206 mol) in methanol (10 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 was achieved using column chromatography (SiO2, petroleum:ether (40:60 v/v) with an increasing gradient of ethyl acetate) which gave 0.95 g (19%) of a yellow solid. 1H-NMR (CDCl3) δ 7.7 (d, 1H), 7.3 (m, 2H), 7.1 (d, 3H), 6.8 (d, 1H), 6.6 (d, 1H), 5.7 (s, 1H), 4.1 (t, 2H), 3.9 (s, 6H), 1.9 (m, 2H), 1.0 (t, 3H). 13C-NMR (CDCl3) δ 160.9, 146.0, 144.9, 128.4, 122.6, 120.2, 112.9, 106.2, 104.9, 70.6, 55.6, 22.4, 10.4. Mass Spectrum m/e (M+1) 343. Anal. Calcd. for C20H22O5: C, 70.16; H, 6.48. Found C, 70.08; H, 6.38.

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