反应详情

Acetic anhydride (9.95 g, 97.5 mmol, 10.0 eq) is added at room temperature to a stirred solution of {trans-4-[2-(3-chloro-6-methoxy-[1,5]naphthyridin-4-yl)-1-formyl-2-hydroxy-ethyl]-cyclohexyl}-carbamic acid tert-butyl ester (4.5 g, 9.7 mmol, 1.0 eq) in anhydrous pyridine (100 mL). After 30 hours stirring at room temperature and 90 hours stirring at 50° C., solvent is removed and the residue is extracted with ethyl acetate (3×100 mL) and a saturated sodium hydrogen carbonate aqueous solution (100 mL). The combined organic layers are dried over sodium sulfate, filtered and concentrated to give the crude product that is purified by column chromatography (silica gel, eluent: petroleum ether:ethyl acetate:dichloromethane, 9:2:1 to 6:2:1, v/v/v) to afford {trans-4-[2-(3-chloro-6-methoxy-[1,5]naphthyridin-4-yl)-1-formyl-vinyl]-cyclohexyl}-carbamic acid tert-butyl ester as a white solid (3.40 g, 79% yield).

1. stirringstirring at 50° C.
2. customsolvent is removed
3. extractionthe residue is extracted with ethyl acetate (3×100 mL)
4. dry with materialThe combined organic layers are dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customto give the crude product that
8. customis purified by column chromatography (silica gel, eluent: petroleum ether:ethyl acetate:dichloromethane, 9:2:1 to 6:2:1, v/v/v)