PRODUCTION OF BIPHENYLTETRACARBOXYLIC ACID

摘要

PURPOSE:To produce the titled compound useful as a raw material of polyimide resin, in high efficiency, by hydrolyzing a biphenyltetracarboxylic acid tetraalkyl ester in pure water solvent in a heterogeneous system using a strongly acidic cation exchange resin. CONSTITUTION:A biphenyltetracarboxylic acid tetraalkyl eter (alkyls are same 1-3C alkyl) is hydrolyzed to obtain biphenyltetracarboxylic acid. The hydrolysis is carried out in pure water solvent in a heterogeneous system using a strongly acidic cation exchange resin (especially a sulfonic acid-type cation exchange resin having a crosslinking degree of 2-10%) as the catalyst. Especially, the reaction is carried out preferably by distilling the by-produced methanol out of the system. EFFECT:The hydrolysis proceeds smoothly.