Patent ID: 7582774

Claim:
A process for producing cyclic-N-hydroxyimide compounds, comprising the step of allowing a cyclic polycarboxylic acid anhydride, a polycarboxylic acid, or a mixture of them to react with hydroxylamine or a salt thereof in an organic solvent selected from a group consisting of carboxylic acids, esters, ketones, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, alcohols, and halogenated hydrocarbons while dewatering by azeotropic distillation thereby yielding a corresponding cyclic N-hydroxyimide compound; wherein the said organic solvent is capable of undergoing azeotropy with water while carrying out dewatering; and wherein the amount of said organic solvent is 10 to 5000 parts by weight to 100 parts by weight of the total of said cyclic polycarboxylic acid anhydride and said polycarboxylic acid used in the reaction.