反应详情

Methyl 3-[4-[(2,4-difluorobenzyl)oxy]-6-methyl-2-oxopyridin-1(2H)-yl]-4 methylbenzoate (14 g, 35.0 mmol) (from step 2) was taken up in THF (25 ml) and H2O. 2.5 N NaOH (aq.) was added and the reaction stirred for 30 minutes at room temperature. The reaction was made acidic via the addition of concentrated HCl. The product was extracted with ethyl acetate. The ethyl acetate extraction was dried over Na2SO4, filtered, and the solvent removed in vacuo. Upon vacuum removal of the solvent, the product crashed out of the ethyl acetate. This precipitate was collected on a filter pad and washed with a 50 ethyl acetate/hexanes to yield a white powder (9 g, 7%). 1H NMR (300 MHz, CDCl3) δ 8.01 (dd, J=, 1.61 Hz, 1H), 7.84 (d, J=1.61 Hz, 1H), 7.52-7.47 (app q, J=8.26, 1H), 7.43 (d, J=8.06 Hz, 1H), 7.00-6.88 (m, 2H), 6.19 (d, J=2.62 Hz, 1H), 6.05 (dd, J=2.62, 1.81 Hz, 1H), 5.17 (s, 2H), 2.19 (s, 3H), 1.90 (s, 3H); ES-HR/MS m/z 386.12 (M+H calcd for C21H18F2NO4 requires 386.1198).

1. extractionThe product was extracted with ethyl acetate
2. extractionThe ethyl acetate extraction
3. dry with materialwas dried over Na2SO4
4. filtrationfiltered
5. customthe solvent removed in vacuo
6. customUpon vacuum removal of the solvent
7. customThis precipitate was collected on a filter pad
8. washwashed with a 50 ethyl acetate/hexanes