Dimethyl-2,6-naphthalenedicarboxylate → 2,6-Naphthalenedicarboxylic acid

Dimethyl-2,6-naphthalenedicarboxylate was hydrolyzed at elevated temperatures and elevated pressures in the batch-mode in a stirred, 300 ml Hastelloy C autoclave reactor. 37.5 Grams of dimethyl-2,6-naphthalenedicarboxylate were charged to the reactor. No catalyst was used. The 2,6-NDA product was separated from the mother liquor by filtration at room temperature followed by washing with about 150 grams of water. The reaction time, temperature, pressure and analysis of the resulting 2,6-naphthalenedicarboxylic acid are provided in Table 2. During each of the runs reported in Table 2, approximately one-half of the solvent was unintentionally lost. This loss of solvent likely caused the removal of methanol from the reaction mixture thereby shifting the equilibrium towards 2,6-naphthalenedicarboxylic acid. Runs 1, 2 and 3 reported in Table 2 were run consecutively in the same autoclave reactor.