Study and modeling of the estherification process of m­nitrobenzoic acid with ethanol

Abstract

In  order  to  obtain  new  pesticides  having  antifungal  activity,  the  estherification  of  m­-nitrobenzoic  acid with ethanol was  studied. A comparative  study was carried  out for  homogeneous and  heterogeneous  catalysis. Because the  heterogeneous catalysis was  proved to  be  better  both  by global yield and by separation of the esther from the reaction mixture, the studies were continued to establish the effects of the catalyst amount or the reaction time and temperature on the yield of esther. An  empirical  model  was  elaborated  by  a  factorial  experiment  of  first  order  2 3  type,  considering reaction  time,  temperature,  and  gr.catalyst/gr.m­nitrobenzoic  acid  mass  ratio  as  independent variables,  while  the  yield  was  chosen  as  optimization  criteria.  The  empirical  model  was  found adequate for the estherification process of m­nitrobenzoic acid with ethanol. Also, an analysis of the model was performed to find the optimal operating conditions, in order to apply this process for an efficient  estherification  of  m­nitrobenzoic  acid  with  ethanol.  The  optimal  values  correspond  to  a temperature of 80 0 C, a reaction time of 7.2 h and a mass ratio gr.catalyst/gr.m­nitrobenzoic acid of 0.6 for an optimal yield of  94%.