1-Methyl-4-ethoxycarbonylpyrazole-5-sulfonyl chloride is an intermediate for the herbicide pyrosulfuron-methyl.
Synthesis
1-Methyl-4-ethoxycarbonylpyrazole-5-sulfonyl chloride was prepared by reacting 1-methyl-4-ethoxycarbonyl pyrazolamine with sodium nitrite with catalyst.