Acetone → HCID 14128067, compound

Participants

Reaction Steps

To the stirred acetone (50 ml) solution of 2.8 g of the 5-chloro-3-(2,6-difluorophenyl)-7,8-dihydrofuro[2,3-g]1,2-benzisoxazole-7-methanol prepared in Example 20, a mixture of chromium (VI) oxide (3.0 g), water (7 ml) and concentrated sulfuric acid (4.2 g) was added dropwise over time, and the agitation was continued for 9 hours at room temperature. The insolubles were filtered off by suction and the acetone was distilled off. Water was added to the residue, and the solution was subjected to extraction with ether. The ether layer was washed with water and dried. After distilling off the solvent, the residue was recrystallized from acetone-water, yielding 1.0 g of 5-chloro-3-(2,6-difluorophenyl)-7,8-dihydrofuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acid. m.p. 239.5°-241° C. This compound exhibited a mass spectrum having a molecular ion peak at m/e 351.

Provenance & Evidence