反应详情

To a solution of the product of Example 8A (500 mg, 2.334 mmol) in DMF (23 mL) was added tert-butyldimethylsilyl chloride (528 mg, 3.501 mmol) and imidazole (238 mg, 3.501). The reaction was stirred at room temperature for 5 hours under nitrogen atmosphere, monitoring by TLC (3:1 pentane:ethyl acetate). Another 0.5 eq. portion of tert-butyldimethylsilyl chloride (176 mg) and imidazole (79 mg) were added and the resultant mixture stirred at room temperature overnight. The majority of the starting material was consumed in 16 hours, as indicated by thin layer chromatography. The reaction was diluted with water and extracted with ethyl acetate (2 times). The combined organic layers were dried over Na2SO4, filtered, and concentrated under reduced pressure to obtain a crude oil which was purified by passage through thick pad of silica gel (3:1 pentane:ethyl acetate) to obtain the product as a clear oil (602 mg). 1H NMR (600 MHz, CDCl3): 8.00 (d, 2H, J=8.3 Hz), 7.40 (d, 2H, J=8.5 Hz), 4.62 (s, 2H), 3.90 (s, 3H), 0.90 (s, 9H), 0.06 (s, 6H).

1. customThe majority of the starting material was consumed in 16 hours
2. additionThe reaction was diluted with water
3. extractionextracted with ethyl acetate (2 times)
4. dry with materialThe combined organic layers were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customto obtain a crude oil which
8. customwas purified by passage through thick pad of silica gel (3:1 pentane:ethyl acetate)