反应详情

LiOH.H2O (60 mg, 1.43 mmol) was added to a solution of fully methylated diflunisal (140 mg, 0.50 mmol) in MeOH:THF:H2O (4.5 mL 1:1:1), and stirred at rt for 4 h. Upon completion, the reaction was acidified with 30% HCl, extracted with ethyl acetate (3×5 mL), dried over MgSO4 and concentrated in vacuo. The residue was purified by flash chromatography (2:1 ethyl acetate:hexane, 1% acetic acid) to afford 33 (122 mg, 93%) as a white solid. 1H NMR (CDCl3, 400 MHz) δ 10.77 (br s, 1H), 8.31 (dd, 1H, J=2.5, 0.9 Hz), 7.75 (dt, 1H, J=8.6, 2.1 Hz), 7.41 (dt, 1H, J=8.9, 6.6 Hz), 7.15 (d, 1H, J=8.8 Hz), 6.94 (m, 1H), 4.13 (s, 3H). 13C NMR (CDCl3, 100 MHz) δ 177.7, 161.4, 158.2, 135.7, 133.9, 131.4, 129.0, 123.5, 118.1, 112.2, 112.0, 104.6, 56.9. HRESIMS calculated for C14H10F2O3 (M−H) 263.0520. found 263.0514. Normal phase HPLC retention time: 21.6 min. Reverse phase HPLC retention time: 11.9 min. >99% pure.

1. extractionextracted with ethyl acetate (3×5 mL)
2. dry with materialdried over MgSO4
3. concentrationconcentrated in vacuo
4. customThe residue was purified by flash chromatography (2:1 ethyl acetate:hexane, 1% acetic acid)