反应详情

A suspension of 1-(3,5-dichloropyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (2.0 g) in Reference Example 22 (2), methylboronic acid (419 mg), 1,1′-bis(di-tert-butylphosphino)ferrocene (631 mg), palladium acetate (299 mg) and tripotassium phosphate (2.97 g) in 1,4-dioxane (35 ml) was stirred with reflux for 8 hours. After completion of the reaction, the mixture was allowed to cool, and ice water and a saturated aqueous solution of ammonium chloride were added thereto, and extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated in vacuo. The obtained residue was purified with silica gel chromatography (n-hexane/ethyl acetate) to give 1-(5-chloro-3-methylpyridin-2-yl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.07 g) as a yellow solid. MS (ESI) m/z: 230 (M+H)+.

1. temperaturewith reflux for 8 hours
2. customAfter completion of the reaction
3. temperatureto cool
4. extractionextracted with chloroform
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. customthe solvent was evaporated in vacuo
7. customThe obtained residue was purified with silica gel chromatography (n-hexane/ethyl acetate)