反应详情

温度

0 °C

10 ml of 2M solution of n-butyllithium in cyclohexane was added dropwise over 10 minutes to a stirred solution of 5.08 g (20 mmol) of bis(trimethylsilyl)malonate in 40 ml of anhydrous ether under nitrogen atmosphere at −60° C. The mixture was then allowed to warm to 0° C. and the solution of 2.3 g (10 mmol) of 3,4,5-trimethoxybenzoyl chloride in 20 ml of anhydrous ethyl ether was added in one portion. The resulting mixture was stirred for 10 min. at 0° C. then shaken with 100 ml of 5% aqueous sodium bicarbonate for 5 minutes. The aqueous phase was acidified to pH=˜1 with cold 4N sulfuric acid and extracted with ethyl ether (3×100 ml). The combined extracts were dried over anhydrous magnesium sulfate, filtered off and evaporated to dryness to give the title compound as a creamy crystals (1.82 g, 71.6%); 1H NMR (CDCl3) δ 3.8-3.92 (m, 9H, OMe); 4.03 (s, 1.8 H, CH2); 5.62 (s, 0.2 H, CH enol); 7.2 (s, 2H, CH aromatic).

1. extractionextracted with ethyl ether (3×100 ml)
2. dry with materialThe combined extracts were dried over anhydrous magnesium sulfate
3. filtrationfiltered off
4. customevaporated to dryness