反应详情

To 1 l of concentrated sulfuric acid, 40 g (0.22 mol) of orthonitrophenylacetic acid were added, followed by stirring at 105°-110° C. for 90 minutes. After cooling, 2.5 l of ice water in limited amounts was added to the reaction mixture. The resultant mixture was extracted with 1 l of ethyl ether. The extract was dried over anhydrous sodium sulfate and the solvent was distilled off, so that 18.1 g (yield: 50.2%) of 2,1-benzisoxazole-3-carboxylic acid was obtained as crystals.

1. temperatureAfter cooling
2. extractionThe resultant mixture was extracted with 1 l of ethyl ether
3. dry with materialThe extract was dried over anhydrous sodium sulfate