反应详情

56.7 g of 4-(3-hydroxypropyl)pyrazole and 45.5 g of triethylamine were dissolved in 500 ml of chloroform and, under cooling with ice, a solution of 88.8 g of α-bromo-2-pivaloyl-2-chloroacetanilide in 300 ml of chloroform was dropwise added thereto in about 1 hour. After completion of the dropwise addition, the solution was stirred for 2 hours, and the reaction solution was washed twice with 300 ml of dilute hydrochloric acid, then twice with 500 ml of water. The reaction solution was dried with anhydrous sodium sulfate, concentrated, and purified by silica gel chromatography to obtain 88.2 g of oily α-pivaloyl-α-[4-(3-hydroxypropyl)pyrazolyl]-2-chloroacetanilide. (Yield: 78%)

1. temperatureunder cooling with ice
2. additionAfter completion of the dropwise addition
3. washthe reaction solution was washed twice with 300 ml of dilute hydrochloric acid
4. dry with materialThe reaction solution was dried with anhydrous sodium sulfate
5. concentrationconcentrated
6. custompurified by silica gel chromatography