反应详情

温度

110 °C

A suspension of 1.4 g of 2-ethyl-5-methyl-2H-pyrazol-3-ol, 1.6 g of calcium hydroxide and 1.3 ml of benzoyl chloride in 70 ml of 1,4-dioxane was stirred at 110° C. for 3.5 h. 1 ml of water was added and the mixture was stirred at 110° C. for 2 h. 25 ml of 2N hydrochloric acid was added. The mixture was stirred at room temperature for 16 h and extracted three times with 60 ml of ethyl acetate. The combined extracts were dried over magnesium sulphate, filtered and evaporated to give 3.1 g of (1-ethyl-5-hydroxy-3-methyl-1H-pyrazol-4-yl)-phenyl-methanone as a yellow oil which was used without further purification. Mass spectrum (ES) m/z 231 [M+H]+, 272 [M+H+CH3CN]+.

1. stirringthe mixture was stirred at 110° C. for 2 h
2. stirringThe mixture was stirred at room temperature for 16 h
3. extractionextracted three times with 60 ml of ethyl acetate
4. dry with materialThe combined extracts were dried over magnesium sulphate
5. filtrationfiltered
6. customevaporated