反应详情

Ethyl-5-(2',4'-dichlorophenyl)-4-isoxazolecarboxylate (50.0 g.; 0.17 mol.) was dissolved in 250 ml. of glacial acetic acid. To the mixture was added 250 ml. of hydrochloric acid and the resultant solution was rapidly stirred at 100° C. for 4 hours. The mixture was then allowed to cool and poured into 2 liters of water. The resultant precipitate was collected, dried, and recrystallized from pentane to yield 5-(2',4'-dichlorophenyl)-4-isoxazolecarboxylic acid (40.0 g.; 93.6% yield) having a melting point of 122°-123° C. and the following analysis:

1. additionTo the mixture was added 250 ml
2. temperatureto cool
3. customThe resultant precipitate was collected
4. customdried
5. customrecrystallized from pentane