反应详情

To a solution of 1-(5-cyclopropylpyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (14 g) in methanol (70 ml) and tetrahydrofuran (70 ml) were added 4 N aqueous solution of sodium hydroxide (70 ml) and water (50 ml), and stirred at room temperature overnight. After completion of the reaction, the organic solvent was evaporated in vacuo, then water and diethyl ether were added thereto, and the aqueous layer was separated. To the aqueous layer was added concentrated hydrochloric acid under ice-cooling to adjust the layer to pH 5, the precipitated solid was collected by filtration, and dried at 60° C. under air blow to give the titled compound (12.4 g) as a white solid. MS (ESI) m/z: 244 (M+H)+.

1. customAfter completion of the reaction
2. customthe organic solvent was evaporated in vacuo
3. additionwater and diethyl ether were added
4. customthe aqueous layer was separated
5. additionTo the aqueous layer was added concentrated hydrochloric acid under ice-
6. temperaturecooling
7. filtrationthe precipitated solid was collected by filtration
8. customdried at 60° C. under air blow