反应详情

100 g of 3-chloro-1-methyl-5-pyrazole-carboxylic acid (the Compound No. 4.1 (a) of the present invention) were suspended in 200 ml of benzene, and 150 ml of thionyl chloride were added thereto dropwise. Then, the mixture was heat-refluxed for 4 hours. The reaction mixture was allowed to cool, and the solvent was then distilled off under reduced pressure. The resulting residue was distilled under reduced pressure to obtain 103 g of the intended 3-chloro-1-methyl-5-pyrazolecarbonyl chloride.

1. temperatureThen, the mixture was heat-refluxed for 4 hours
2. temperatureto cool
3. distillationthe solvent was then distilled off under reduced pressure
4. distillationThe resulting residue was distilled under reduced pressure