Catalystic synthesis of methyl paraben by aminosulfonic acid

Methyl paraben(Methyl-p-hydroxy benzonate)was synthesized from p-hyroxybenzoic acid and methanol,aminosulfonic acid was used as catalyst.The effects of molar ratio of alcohol to acid reaction,reaction time,the amount of catalyst on esterification yield were studied.The optimal reaction conditions were obtained by orthogonal experiment technology and the results as follows:(take p-hydroxybenzoic acid of 0.1mol as basis)the molar ratio of methanol and hydroxybenzoic acid is 5,the dosage of aminosulfonic acid is 2.0g,the reaction time is 7h,the yield of esterification is 92.5%.Aminosulfonic acid is a high effencient,environmentally friendly and green esterification catalyst.