Chlorosulfonic acid → 5-(Chlorosulfonyl)-2-ethoxybenzoic acid

Participants

Reaction Steps

In a 250 ml three-neck flack, 2-ethoxy benzoic acid (50 g, 0.30 mol) was added dropwise to an ice-cooled mixtures of sulfoxide dichloride (22 ml, 0.30 mol) and chlorosulfonic acid (82.6 ml, 1.24 mol) under stirring. At the same time, the temperature of the reacting mixture was kept below 25° C. The resulting mixture was stirred at room temperature for 18 hours and then poured into ice water with stirring, and white deposit appeared. The reaction mixture was stirred for another 1 hour, filtered, washed with water, and dried in vacuum, which gave 64.4 g of crude product as white solid (II) (yield 81%). m.p. 108-110° C. The crude product was used directly in the next step without further purification.

Provenance & Evidence