反应详情

To a cooled (−78° C.) solution of LHMDS (20.1 mL, 1.0 M in THF, 20.1 mmol) in THF (10 mL), was added tert-butyl acetate (2.71 mL, 20.1 mmol). After 30 min, a solution of the title compound of Example 11 Step A (1.59 g, 6.7 mmol) in THF (10 mL) was added. After 30 min, the reaction mixture was placed in a 0° C. bath, and was stirred at this temperature for 3 h, whereupon it was quenched by addition of sat. aq. NaHCO3. The aqueous phase was extracted with EtOAc, and the organic phase was concentrated in vacuo. Purification by flash chromatography on silica gel (0 to 30%, then 30 to 100% EtOAc in hexanes) provided the title compound: LCMS C, tr=2.38 min, m/z 252.2 [M−tBu+H]+; 1H NMR (500 MHz, CDCl3) δ 7.66 (d, J=2.0 Hz, 1H), 7.34 (dd, J=9.0, 2.0 Hz, 1H), 7.31 (d, J=9.0 Hz, 1H), 7.21 (s, 1H), 4.06 (s, 3H), 3.87 (s, 2H), 1.49 (s, 9H).

1. waitAfter 30 min
2. customwas placed in a 0° C.
3. customwas quenched by addition of sat. aq. NaHCO3
4. extractionThe aqueous phase was extracted with EtOAc
5. concentrationthe organic phase was concentrated in vacuo
6. customPurification by flash chromatography on silica gel (0 to 30%