反应详情

(Trimethylsilyl)diazomethane (2.0M hexanes, 4.8 mL) was added dropwise to a benzene/MeOH solution (7/3, 50 mL) containing the intermediate from Step A (2.8 g, 8.0 mmol). After 20 minutes AcOH was added dropwise to quench the excess reagent. The solution was concentrated and the residue purified by silica gel chromatography using a hexanes/ethyl acetate gradient to give the title compound. 1H NMR (500 MHz, CDCl3): δ 7.98 (d, J=8.2 Hz, 2H); 7.43 (d, J=8.2 Hz, 1H); 7.29 (d, J=8.2 Hz, 2H); 6.63 (dd, J=3.0, 8.7 Hz, 1H); 6.50 (d, J=3.0 Hz, 1H); 3.93 (s, 3H); 3.68 (s, 3H); 3.26-3.19 (m, 1H); 2.96 (d, J=7.0 Hz, 2H); 1.34 (d, J=6.9 Hz, 3H). LCMS1 4.14 min. (M-31)=331

1. customto quench the excess reagent
2. concentrationThe solution was concentrated
3. customthe residue purified by silica gel chromatography