Chlorosulfonic acid → 1-methyl-1H-pyrazole-4-sulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

Add 1-methyl-1H-pyrazole (100 g, 1.18 mol) dropwise to chlorosulfonic acid (325 mL, 4.84 mol) stirring at 0° C. under nitrogen atmosphere. Heat reaction mixture at 110° C. for 3 hr. Cool to room temperature, then pour carefully into crushed ice with stirring. Recover the resulting white solid by vacuum filtration, wash with water, and dry under vacuum. Use the resulting material (72.2 g, 33%) without further purification.

Provenance & Evidence