Реакция #501524

Уравнение реакции

water

sulfuric acid

5-bromo-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-methanol

→

5-bromo-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acid

Выход 54.9%

Растворители

acetone

Условия реакции

Обработка

1. 1
   workup.ADDITIONwas added dropwise over time
2. 2
   ФильтрацияThe insolubles were filtered off by suction
3. 3
   workup.DISTILLATIONAfter distilling off the acetone, water
4. 4
   workup.ADDITIONwas added to the residue
5. 5
   Экстракцияthe mixture was subjected to extraction with ether
6. 6
   ПромывкаThe ether layer was washed with water
7. 7
   Другоеdried
8. 8
   workup.DISTILLATIONAfter distilling off the solvent
9. 9
   Другоеthe residue was recrystallized with acetone-water

Методика

A portion (0.7 g) of the 5-bromo-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-methanol prepared in Example 4 was dissolved in 50 ml of acetone. To the stirred solution, a mixture of chromium (VI) oxide (1 g), water (3 ml) and concentrated sulfuric acid (1.4 g) was added dropwise over time, and the solution was stirred for 6 hours at room temperature. The insolubles were filtered off by suction. After distilling off the acetone, water was added to the residue and the mixture was subjected to extraction with ether. The ether layer was washed with water and dried. After distilling off the solvent, the residue was recrystallized with acetone-water, yielding 0.4 g of 5-bromo-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acid. m.p. 241.5°-243.5° C. (with decomposition).

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