反应详情

A solution of the title compound from Step B (0.10 g, 0.32 mmol) in acetic acid (1.60 mL) was heated at 100° C. for 1 hour, then cooled to room temperature and concentrated under reduced pressure. The resulting residue was diluted with ethyl acetate, washed sequentially with aqueous 1 N sodium hydroxide solution and brine, dried over magnesium sulfate, filtered and concentrated. Purification by flash chromatography on silica gel (50-80% ethyl acetate in hexanes) provided the title compound: LCMS m/z 296.07 [M+H]+; 1H NMR (500 MHz, CDCl3) δ 9.41 (d, J=1.9 Hz, 1 H), 9.26 (d, J=1.9 Hz, 1 H), 8.22 (m, 1 H), 7.75 (dd, J=8.8, 4.8 Hz, 1 H), 7.32 (dd, J=8.6, 2.3 Hz, 1 H), 7.10-7.06 (m, 1 H), 3.65-3.61 (m, 1 H), 2.73 (s, 3H), 1.26-1.20 (m, 2 H), 0.81-0.77 (m, 2 H).

1. concentrationconcentrated under reduced pressure
2. additionThe resulting residue was diluted with ethyl acetate
3. washwashed sequentially with aqueous 1 N sodium hydroxide solution and brine
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customPurification by flash chromatography on silica gel (50-80% ethyl acetate in hexanes)