| 摘要 |
PURPOSE:To obtain the titled compound in high purity and yield, by obtaining the titled compound from a special reaction solution of maleic anhydride with an aromatic diamine prepared by subjecting the reaction solution to a concentration step under specific conditions, deposition and separation step with an aqueous solution containing a specific amount of a basic substance and washing step with water. CONSTITUTION:An aromatic bismaleimide useful for thermosetting resins having improved heat resistance, dimensional stability, etc. is separated from a reaction solution obtained by distilling away condensed water from a reaction solution of maleic anhydride with an aromatic diamine in an organic solvent in the presence of an acid catalyst. In the process, the solvent is first removed at 50-120 deg.C temperature under reduced pressure to concentrate the above-mentioned reaction solution. The concentrated reaction solution is then dropped into an aqueous solution containing a basic compound in an amount of 1-1.5 equivalents based on the total amount of excess maleic anhydride and the acid catalyst or the above-mentioned aqueous solution is dropped into the above-mentioned concentrated solution to deposit the above-mentioned imide as a solid, which is then separated and washed with water to afford the above-mentioned imide industrially and advantageously in high purity and yield.
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