摘要 |
Disclosed is a process for preparing 3,4,5,6-tetrahydrophthalimide comprising the steps of: (i) reacting a crude 3,4,5,6-tetrahydrophthalic anhydride containing as impurities at least one carboxylic anhydride (A) selected from the group consisting of phthalic anhydride, hexahydrophthalic anhydride and structural isomers of 3,4,5,6-tetrahydrophtalic anhydride with an alcohol for conversion of substantially all the carboxylic anhydride (A) into the monoester thereof to obtain a reaction mixture containing the monoester, 3,4,5,6-tetrahydrophthalic anhydride, and if any, a monoester of 3,4,5,6-tetrahydrophthalic anhydride, and (ii) adding ammonia to the reaction mixture to subject the 3,4,5,6-tetrahydrophthalic anhydride, and if any, the monoester thereof to a reaction for conversion into 3,4,5,6-tetrahydrophthalimide.
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