Patent ID: 7355071
Filing Date: 2008-04-08
Classification: C07C

Abstract:
1. A method for preparing 2,6-naphthalene dicarboxylic acid, which comprises the steps of, hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate under the presence of a basic compound to give a solution of the di-basic compound salt of 2,6-naphthalene dicarboxylic acid, and aciding out the solution to give 2,6-naphthalene dicarboxylic acid, wherein the hydrolyzing step comprises; hydrolyzing one part by weight of di-lower alkyl 2,6-naphthalene dicarboxylate in 3-50 parts by weight of water in the presence of (A), (B) and the basic compound: (A) 20-200 parts by weight of a hydrophobic organic solvent selected from the group consisting of an aromatic compound, a ketone and an ether per 100 parts by weight of di-lower alkyl 2,6-naphthalene dicarboxylate, (B) 0.01-10 parts by weight of an additive selected from the group consisting of a polyalkylene glycol and a surface active agent per 100 parts by weight of di-lower alkyl 2,6-naphthalene dicarboxylate; and separating the reaction mixture into organic phase and aqueous phase to give the aqueous solution of the di-basic compound salt of 2,6-naphthalene dicarboxylic acid.