反应详情

Under nitrogen, a solution of compound 201a (3 g, 1 eq.) in 1,4-dioxane (30 mL) was added at 0° C. to a solution of compound 214 (4.1 g, 1.2 eq.) in 1,4-dioxane. The reaction mixture was stirred at room temperature overnight. The solvent was removed under reduced pressure and the residue was purified by chromatography on silica gel to yield compound as a beige solid 217a in 75% yield. 1H NMR (CDCl3, 400 MHz): δ (ppm) (ppm) 1.43 (d, J=6.98 Hz, 6H), 2.65 (s, 3H), 3.26 (hep, J=6.98 Hz, 1H), 3.92 (s, 3H), 6.69 (dd, J=2.59 and 8.80 Hz, 1H), 7.2 (d, J=0.84, 1H), 7.87 (d, J=8.9 Hz, 1H), 8.58 (d, J=2.59 Hz, 1H), 13.5 (br s, 1H); MS (ESI, EI+): m/z=319 (MH+).

1. customThe solvent was removed under reduced pressure
2. customthe residue was purified by chromatography on silica gel