Thionyl Chloride → Ethyl 5-(chlorocarbonyl)-1-methyl-1H-pyrazole-4-carboxylate

Participants

Reaction Steps

A mixture of 2-ethyl-2H-pyrazole-3,4-dicarboxylic acid 4-ethyl ester (Example 10, steps 1-3, 3 g, 15 mmol) and thionyl chloride (40 ml) was heated to reflux (4 h). The thionyl chloride was evaporated, and the residue (3.38 g, 64%) was used in the next step without further purification.

Provenance & Evidence