Sulfuric Acid → 2,4,5-Trifluorobenzenesulfinic acid

Participants

Reaction Steps

To a solution of sodium sulfite (153 g, 1214 mmol) in 1000 mL water was added a solution of 2,4,5-trifluorobenzene-1-sulfonyl chloride (40 g, 173 mmol) in dioxane (300 mL) dropwise. After the complete addition of sulfonyl chloride, the reaction was basified to about pH 14 by the addition of 1 N NaOH, and the reaction mixture was stirred overnight. The reaction mixture was cooled in ice bath and acidified using ˜100 mL concentrated H2SO4 to pH about 1. The mixture was extracted with EtOAc and CH2Cl2 and the combined organic layers were dried over Na2SO4, filtered and concentrated to afford 2,4,5-trifluorobenzenesulfinic acid (34 g, 100%).

Provenance & Evidence