4-Hydroxybenzoic Acid → 3-(Chlorosulfonyl)-4-hydroxybenzoic acid

Participants

Reaction Steps

55 g of p-Hydroxybenzoic acid (I) (Aldrich) was added in small portions to 545 g of chlorosulfonic acid (Aldrich) while stirring at room temperature. After 18 hours the reaction mixture was poured in a thin stream upon crushed ice (5 liters). The product was filtered and the precipitate dissolved in ethyl acetate. The solution was then washed with brine, dried with magnesium sulfate, filtered and evaporated to yield 65 g of 3-chlorosulfonyl-4-hydroxybenzoic acid (II), m.p. 181°-182° C.

Provenance & Evidence