Green Process for the Production of 4-(β-sulfotaethylsulfone)-<i>N</i>-Ethyl-Aniline

Abstract

4-(β-sulfatoethylsulfone)-N-ethyl-aniline was synthesized from 4-(β-hydroxyethyl-sulfonyl)-N-ethyl-aniline in the presence of sulfuric acid using toluene andN,N-dimethyl-dodecylamine as mix solvent. The product was efficiently precipitated from the reaction mixture by addition of a sufficient amount of acetone. Several influencing factors on the esterification were investigated, and the results show that, the optimal conditions were: the molar ratio of 4-(β-hydroxyethylsulfonyl)-N-ethyl-aniline,N,N-dimethyl-dodecylamine and sulfuric acid was 1:1:1.5, the dosage of toluene 800 mL per molar 4-(β-hydroxyethylsulfonyl)-N-ethyl-aniline, and the esterification was taken for 9 hours under reflux. Under the optimal conditions, total yield of the product was 85% with the purity of 97%. It was also found that the yield of product can be promoted up to 90 % by using the recycled solvent. The structure of product was characterized by MS.