Pd(OAc)2-catalyzed oxidative carbonylation of aromatics: synthesis of naphthalenecarboxylic acids

The liquid-phase oxidative carbonylation of aromatics leading to aromatic carboxylic acids is studied to develop new approaches to 2,6-naphthalenedicarboxylic acid (NDA) preparation. It is shown that the catalytic system Pd(OAc)(2)/K2S2O8 allows the synthesis of naphthalic anhydride (NAn) by direct oxidative carbonylation of naphthalene under mild conditions (25 degrees C, 2 atm CO). The subsequent alkaline hydrolysis of NAn and isomerization of the obtained 1,8-naphthalenedicarboxylic acid salt is known to lead to NDA. (C) 2013 Elsevier Ltd. All rights reserved.