4-(dimethylamino)benzenesulphonic acid

121-69-7

121-58-4

4-(Dimethylamino)benzenesulfonic acid was synthesized as follows: to a 250 mL three-necked round-bottomed flask, a solution of N,N-dimethylaniline (20 g, 165.29 mmol) in ether (40 mL) was added under ice bath conditions. Subsequently, a solution of sulfuric acid (16.1 g, 161.00 mmol) in ether (160 mL) was added slowly and dropwise. Upon completion of the reaction, the ether solvent was removed by rotary evaporator. The resulting mixture was reacted under stirring conditions at 170 °C under vacuum for 4 hours. Eventually, 10.5 g of 4-(dimethylamino)benzenesulfonic acid was obtained in 32% yield and the product was a white solid.