Catalytic Synthesis of Ethyl p - hydroxybenzonate with the Special Superacid SO_4~(2-)/α-Fe_2O_3

The catalytic esterification for preparing ethyl p - hydroxybenzonate with special superacid is described. The special superacid is synthesized and the conditions of esterification are investigated. It showed that the special superacid SO42- /α- Fe2O3 is an excellent catalyst,the yield of ethyl p- hydroxybenzonate can reach 84.3 % under ratio of ethyl alcohol and p- hydroxybenzoic acid 3:1, reation time of 4 hour and amount of catalyst of 9.06 %, which exceeds general solid superacid catalyst.