[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[O:14])[CH2:9][CH2:10][C:11]([OH:13])=[O:12])=[CH:4][C:3]=1[CH3:15].OS(O)(=O)=O.[CH3:21]O>>[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[O:14])[CH2:9][CH2:10][C:11]([O:13][CH3:21])=[O:12])=[CH:4][C:3]=1[CH3:15]To the crude 4-(4-fluoro-3-methyl-phenyl)-4-oxo-butyric acid in 50 mL methanol was added 500 μL concentrated H2SO4 at 25° C. After stirring for 16 h, the mixture was concentrated under reduced pressure and 50 mL water was added. The mixture was extracted with ethyl acetate (3×50 mL) and the combined organic layers washed with brine (2×30 mL) and the product isolated using silica gel chromatography to afford 1.2 g of the title compound as a colorless oil.
Wird geladen…