反应详情

Nitric acid (70%, 3.0 mL, 47 mmol) is slowly added to a mixture of methyl 2-[(6-chloro-1,2-benzisoxazol-3-yl)oxy]propionate (6.0 g, 23.5 mmol) in concentrated sulfuric acid (50 mL) while maintaining the temperature below 10° C. The reaction mixture is stirred for 1 hour on an ice/water bath and poured onto ice. The resultant aqueous mixture is diluted with ether, stirred for several minutes and the ether is allowed to evaporate overnight. The resultant mixture is filtered to obtain a solid which is dissolved in methylene chloride. The methylene chloride solution is dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a solid which is recrystallized from an ether/hexanes solution to give the title product as a solid, mp 98°-101° C.

1. temperaturewhile maintaining the temperature below 10° C
2. additionpoured onto ice
3. stirringstirred for several minutes
4. customto evaporate overnight
5. filtrationThe resultant mixture is filtered
6. customto obtain a solid which
7. dry with materialThe methylene chloride solution is dried over anhydrous sodium sulfate
8. concentrationconcentrated in vacuo
9. customto obtain a solid which
10. customis recrystallized from an ether/hexanes solution