反应详情

To a stirred solution of Step 4 intermediate (12.5 g, 59.52 mmol) in boron trifluoride diethyl etherate (300 ml) was added N-iodosuccinimide (19.9 g, 89.28 mmol) and the mixture was stirred for 3 h at room temperature under nitrogen atmosphere. The reaction mixture was diluted with water (100 ml), extracted with ethyl acetate (3×200 ml) and the combined organic layers were washed with water (2×150 ml), dried over Na2SO4 and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using 2% ethyl acetate in chloroform to obtain 9.7 g of the product as a pale brown solid; 1H NMR (300 MHz, DMSO-d6) δ 2.37 (s, 3H), 3.21 (s, 3H), 3.42 (s, 3H); MS (m/z) 337.11 (M+H)+.

1. extractionextracted with ethyl acetate (3×200 ml)
2. washthe combined organic layers were washed with water (2×150 ml)
3. dry with materialdried over Na2SO4
4. concentrationconcentrated under reduced pressure
5. customThe crude product was purified by silica gel column chromatography