反应详情

A mixture of Step 1 intermediate (10.0 g, 62.893 mmol), acetyl chloride (4.47 ml, 62.893 mmol) and anhydrous zinc chloride (8.57 g, 62.893 mmol) in dry benzene (150 ml) was refluxed for 48 h. The solvent was completely evaporated under reduced pressure, diluted with water (500 ml) and extracted with chloroform (3×150 ml). The combined organic layers were washed with water (150 ml), dried (Na2SO4) and concentrated. The residue obtained was purified by silica gel column chromatography by using 30% ethyl acetate in petroleum ether to afford 4.7 g of the product as a pale yellow solid; 1H NMR (300 MHz, CDCl3) δ 2.38 (s, 3H), 2.55 (s, 3H), 3.37 (s, 3H), 3.48 (s, 3H).

1. customThe solvent was completely evaporated under reduced pressure
2. additiondiluted with water (500 ml)
3. extractionextracted with chloroform (3×150 ml)
4. washThe combined organic layers were washed with water (150 ml)
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated
7. customThe residue obtained
8. customwas purified by silica gel column chromatography