Method for preparing 2,6-Naphtalene dicarboxyclic acid

摘要

Disclosed is an improved method for preparing 2,6-naphthalene dicarboxylic acid from di-lower alkyl 2,6-naphthalene dicarboxylate, which is characterized in that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specified amount of water in the presence of specified amount of hydrophobic organic solvent and an additive; that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specific amount of a mixed solvent of non-water miscible alcohol and water; or in that di-lower alkyl 2,6-naphthalene dicarboxylate is hydrolyzed in two steps wherein the 1st step comprises hydrolyzing said ester in a water miscible organic solvent in the presence of a small amount of water, and the 2nd step comprises further hydrolyzing the reaction.