反应详情

A slurry of 4-[3,5-difluoro-4-(methylsulfinyl)phenyl]-5-methyl-3-phenylisoxazole (2.3 g, 6.8 mmol) (step 9 example 14), sodium acetate (3.4 g, 41 mmol) in acetic anhydride (30 mL) was heated and held at reflux for 9 hours. The mixture was concentrated on at reduced pressure and the residue was treated with dilute aqueous sodium bicarbonate and extracted with dichloromethane (1×200 mL, 2×75 mL). The combined extracts were washed with dilute sodium bicarbonate, dilute ammonium chloride, dried with magnesium sulfate and concentrated. The product was purified by silica gel chromatography using 1% ethyl acetate/50% dichloromethane in hexanes to give {[2,6-difluoro-4-(5-methyl-3-phenylisoxazol-4-yl)phenyl]thio}methyl acetate as a white solid (2.1 g, 82%), MP 130.3-130.3° C. 1H NMR (CDCl3/400 MHz) 7.34-7.43 (m, 5H), 6.73-6.79 (m, 2H), 5.29 (s, 2H), 2.49 (s, 3H) 2.05 (s, 3H). HRMS m/z 376.0822 (M+H+, Calcd 376.0819). Anal. Calcd for C19H15F2NO3S: C, 60.79; H, 4.03; N, 3.73. Found: C, 60.44; H, 4.09; N, 3.66.

1. temperatureat reflux for 9 hours
2. concentrationThe mixture was concentrated on at reduced pressure
3. additionthe residue was treated with dilute aqueous sodium bicarbonate
4. extractionextracted with dichloromethane (1×200 mL, 2×75 mL)
5. washThe combined extracts were washed with dilute sodium bicarbonate, dilute ammonium chloride
6. dry with materialdried with magnesium sulfate
7. concentrationconcentrated
8. customThe product was purified by silica gel chromatography