4-Fluorobenzoic Acid → 3-(Chlorosulfonyl)-4-fluorobenzoic acid

Participants

Reaction Conditions

Reaction Steps

Chlorosulphonic acid (100 ml, 1.5 mol) was gradually added to 4-fluorobenzoic acid (43 g, 0.307 mol) with stirring. The clear dark yellow mixture was heated to 150° C. for 24 hours. The yellow solution was cooled back to room temperature and poured onto ice with vigorous stirring. The white precipitate was filtered and pressed dry. The solid was dried overnight in a desiccator under vacuum and over activated silica (54.65 g, 75%). Mp: 116–117° C.; m/z (LC-MS, ESP), RT=4.03 min, (M−−1)=237–239 (ratio 1:3).

Provenance & Evidence