反应详情

温度

0 °C

Sodium hydride (188 mg, 4.4 mmol) was suspended in dry THF (1 ml) and cooled to 0° C. A solution of 5-amino-4-chloro-3-methylisoxazole (mg, mmol) in dry THF (1 ml) was added with stirring. Once the addition was complete, the reaction mixture was warmed to room temperature for 10 min. The solution was recooled to 0° C., and 4-biphenylsulfonyl chloride (0.283 ml, 2.2 mmol) was added. Stirring was continued at 25° C. for 2 h. Excess sodium hydride was decomposed by the addition of methanol (0.4 ml) followed by water (0.5 ml). THF was removed under reduced pressure and the residue was dissolved in water (20 ml) and basified by addition of sodium hydroxide (pH 9-10). Neutral impurities were removed by extraction with ethyl acetate (2×10 ml). The aqueous layer was acidified to pH 2-3 using concentrated HCl and extracted with ethyl acetate (3×10 ml). The combined organic layer was dried over magnesium sulfate. Removal of the solvent gave N-(4-chloro-3-methyl-5-isoxazolyl)-4-biphenylsulfonamide in 83% yield. This product was purified by recrystallization from ethyl acetate/hexanes as a white solid, m.p. 129°-132° C.

1. additionOnce the addition
2. temperaturethe reaction mixture was warmed to room temperature for 10 min
3. customwas recooled to 0° C.
4. stirringStirring
5. customTHF was removed under reduced pressure
6. dissolutionthe residue was dissolved in water (20 ml)
7. additionbasified by addition of sodium hydroxide (pH 9-10)
8. customNeutral impurities were removed by extraction with ethyl acetate (2×10 ml)
9. extractionextracted with ethyl acetate (3×10 ml)
10. dry with materialThe combined organic layer was dried over magnesium sulfate
11. customRemoval of the solvent