Hydrochloric Acid → 3-(((2,5-Dimethylphenyl)methyl)amino)benzenesulfonic acid

Participants

Reaction Steps

To a stirred slurry of 52.0 g (0.30 mole) of 3-aminobenzenesulfonic acid in 225 ml of hot (65° C.) water was added 83.0 g (0.61 mole) of sodium acetate trihydrate and 75 ml of acetonitrile. The temperature was stabilized at approximately 67°-68° C. and a solution of 30.93 g (0.20 mole) of 2,5-dimethylbenzyl chloride in 75 ml of acetonitrile added dropwise over 1 hr. The resulting orange solution was refluxed for 31/2 hrs, then acidified with 40 ml of conc. HCl while simultaneously distilling off 80 ml of acetonitrile. After placing the reaction mixture in a refrigerator a flocculent cream-colored precipitate formed which was collected by vacuum filtration, washed with water and air-dried. The collected solids were then slurried in 400 ml of boiling methanol for 20 minutes, then vacuum filtered and then dried in vacuo at about 60° C., which afforded 30.86 g (53.0% yield) of purified 3-(((2,5-dimethylphenyl)methyl)amino)benzenesulfonic acid as a white powder having a melting point greater than 275° C.

Provenance & Evidence