PRODUCTION OF HIGH-PURITY DIMETHYL 2,6-NAPHTHALENEDICARBOXYLATE

PURPOSE:To obtain the above compound, by esterifying 2,6-naphtha lenedicarboxylic acid prepared by oxidizing a 2-acyl-6-alkylnaphthalene, separat ing crude dimethyl 2,6-naphthalenedicarboxylate by filtration, washing the resul tant compound with methanol and subjecting the washed compound to distilla tion under reduced pressure, dissolution in heated methanol, cooling and crystalli zation. CONSTITUTION:A 2-acyl-6-alkylnaphthalene are a raw material is oxidized in the liquid phase to provide crude 2,6-naphthalenedicarboxylic acid (containing isomers consisting essentially of 2,7-naphthalenedicarboxylic acid as an impurity), which is then reacted with methanol in the presence of an esterification catalyst to afford crude dimethyl 2,6-naphthalenedicarboxylate. The resultant compound is subsequently separated by filtration, washed with methanol, distilled under reduced pressure, dissolved in heated methanol, cooled and crystallized to provide the aimed high-purity dimethyl 2,6-naphthalenedicarboxylate useful as a raw material for fibers, films and resins.