Chlorosulfonic acid → 5-(Chlorosulfonyl)-2,4-difluorobenzoic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of chlorosulfonic acid (200 mL) and 2,4-difluorobenzoic acid (40 g, 253 mmol, 1 equiv) was heated to 155° C. for 3 h. The reaction was cooled to RT and poured slowly over ice. The product was extracted into ether and the organics dried over MgSO4, filtered and concentrated to give 5-(chlorosulfonyl)-2,4-difluorobenzoic acid 6a as brown solid (61 g, 94% yield).

Provenance & Evidence