反应详情

Toluene (40 ml) and thionyl chloride (8.0 ml) were added to 1-(4-bromophenyl)-5-methyl-1H-pyrazole-4-carboxylic acid (20.50 g) described in reference Example 13, stirred under reflux and the solvent was evaporated in vacuo. Pyridine (20 ml) and ethanol (40 ml) were added to the residue, and the mixture was stirred again under reflux and then the solvent was evaporated in vacuo. A saturated aqueous solution of sodium bicarbonate was added to the residue, and the mixture was extracted with ethyl acetate and the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The resulting solid was washed with n-hexane to give 1-(4-bromophenyl)-5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (15.83 g).

1. temperatureunder reflux
2. customthe solvent was evaporated in vacuo
3. additionPyridine (20 ml) and ethanol (40 ml) were added to the residue
4. stirringthe mixture was stirred again
5. temperatureunder reflux
6. customthe solvent was evaporated in vacuo
7. additionA saturated aqueous solution of sodium bicarbonate was added to the residue
8. extractionthe mixture was extracted with ethyl acetate
9. washthe organic layer was washed with saturated brine
10. dry with materialdried over anhydrous magnesium sulfate
11. concentrationconcentrated in vacuo
12. washThe resulting solid was washed with n-hexane