反应详情

To an ice-cooled mixture consisting of 500 mg of 2-amino-5-ethoxycarbonyl-4,6-dimethylbenzoic acid, 15 ml of benzene, and 0.3 ml of pyridine was added dropwise with stirring a solution of 323 mg of isobutyryl chloride in 2 ml of benzene. After completion of the addition, the reaction mixture was further stirred for 5 hours at room temperature, and then heated to reflux for one hour. After cooling, the mixture was shaken with dilute hydrochloric acid and the layers were separated. The slightly acidic aqueous layer was extracted with ethyl acetate, and the combined organic extracts were washed with water, dried over anhydrous sodium sulfate, and evaporated. The resulting residue was recrystallized from ethyl ether/n-hexane to yield 523 mg of 5-ethoxycarbonyl-2-isobutyrylamino-4,6-dimethylbenzoic acid.

1. additionwas added dropwise
2. additionAfter completion of the addition
3. temperatureheated
4. temperatureto reflux for one hour
5. temperatureAfter cooling
6. customthe layers were separated
7. extractionThe slightly acidic aqueous layer was extracted with ethyl acetate
8. washthe combined organic extracts were washed with water
9. dry with materialdried over anhydrous sodium sulfate
10. customevaporated
11. customThe resulting residue was recrystallized from ethyl ether/n-hexane