反应详情

A mixture of 2-methyl-2H-pyrazole-3,4-dicarboxylic acid 4-ethyl ester (6.00 g) and thionyl chloride (82.8 g) was refluxed for 4 h. Excess thionyl chloride was removed under educed pressure; the obtained crude product (7.26 g, assumed purity ˜60%, 66%) was used in the next step without further purification.

1. temperaturewas refluxed for 4 h
2. customExcess thionyl chloride was removed