| 摘要 |
PURPOSE:To reuse aniline effectively without causing any deterioration of catalytic activity, by heat-treating the aniline recovered from a reaction product and separating with distillation in obtaining indole from aniline and ethylene glycol. CONSTITUTION:Ethylene glycol is reacted with an excess amount of aniline in the vapor phase in the presence of a catalyst in a reactor to obtain indoe. In the process, before separating and recovering the aniline by distillation and refeeding the recovered aniline to the reactor, a solution containing reaction by-products and the aniline is heat-treated at 100-350 deg.C, preferably 150-250 deg.C for 10min-10hr to convert the reaction by-products into nonvolatile substances and facilitate the separation thereof from the aniline suitable for reuse by distillation. EFFECT:The catalyst activity is maintained for a long period, and indole can be produced in high yield.
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