Method of purification of 3,4,5,6-tetrahydrophthalic acid anhydride.

摘要

Disclosed is a process for purifying 3,4,5,6-tetrahydrophthalic anhydride, comprising the steps of bringing a crude 3,4,5,6-tetrahydrophthalic anhydride (comprising a 3,4,5,6-tetrahydrophthalic anhydride as the main component and an acid anhydride (a) as impurities which contains at least one of 1,2,3,6-tetrahydrophthalic anhydride, hexahydrophthalic anhydride, phthalic anhydride, and structural isomers of 3,4,5,6-tetrahydrophthalic anhydride) into contact with a medium comprising at least one of water and monohydric or polyhydric alcohols at a temperature in the range of room temperature to about 160 DEG C so as to hydrolyze the acid anhydride (a) and/or convert it into a monoester; and separating the 3,4,5,6-tetrahydrophthalic anhydride in a solid state from the reaction mixture.