Preparation method of high-purity indole

A high-purity, indole technology, applied in organic chemistry and other directions, can solve problems such as affecting the quality of indole, and achieve the effects of low raw material cost and high yield

Active Publication Date: 2016-06-08
NANTONG WANNIANCHANG PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] However, whether it is extracting indole or synthesizing indole, it contains more or less the main impurity 3-methylindole, and 3-methylindole (3-methylindole) has fecal odor, also known as skatole (skatole) , when the concentration is high, the breath is disgusting, which seriously affects the quality of indole

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A preparation method of high-purity indole, comprising the following steps:

[0023] (1) Synthetic 2-sodium sulfonate indoline: in the 2000L reactor, suck 250kg ethanol, open stirring, drop into 140kg indole crude product, stirring and dissolving. Start to drop 1400kg of 20% sodium bisulfite solution, and control the dropping time to be 2h. After the dropwise addition, keep warm at 30°C for 20h. After the reaction was completed, the reaction solution was suction filtered and washed with ethanol to obtain about 300 kg of intermediate 2-sodium indoline sulfonate.

[0024] (2) Hydrolysis: transfer the filter cake to an alkaline hydrolysis kettle (the filter cake is about 300kg), add 1000L of water and stir, then add 100kg of sodium hydroxide in batches, heat up and steam out ethanol, and keep a small amount of reflux for 20h at an internal temperature above 95°C. Cool down to 20°C, filter and centrifuge, and wash the filter cake with water. Obtain about 125kg of high-pu...

Embodiment 2

[0026] A preparation method of high-purity indole, comprising the following steps:

[0027] (1) Synthetic 2-sodium sulfonate indoline: in the 2000L reactor, suck 700kg methyl alcohol, open stirring, drop into 140kg indole, stirring and dissolving. Start to drop 840 kg of 23% potassium bisulfite solution, and control the dropping time for 3 hours. After the dropwise addition, keep warm at 35°C for 20h. After the reaction was completed, the reaction liquid was suction filtered and washed with methanol to obtain about 300 kg of intermediate 2-sodium indoline sulfonate.

[0028] (2) Hydrolysis: transfer the filter cake to an alkaline hydrolysis kettle (the filter cake is about 300kg), add 1000L of water and stir, then add 100kg of potassium hydroxide in batches, heat up to distill methanol, keep the internal temperature above 95°C, and keep a small amount of reflux for 20h. Cool down to 20°C, filter and centrifuge, and wash the filter cake with water. Obtain about 120kg of high...

Embodiment 3

[0030] A preparation method of high-purity indole, comprising the following steps:

[0031] (1) Synthesis of 2-sodium sulfonate indoline: Inhale 250kg of ethanol in a 2000L reactor, start stirring, drop in 140kg of indole crude product, stir and dissolve. Start to drop 900kg of 30% sodium bisulfite solution, and control the dropping time to be 2h. After the dropwise addition, keep warm at 30°C for 20h. After the reaction was completed, the reaction liquid was suction filtered and washed with ethanol to obtain about 290 kg of intermediate 2-sodium indoline sulfonate.

[0032] (2) Hydrolysis: transfer the filter cake to an alkaline hydrolysis kettle (the filter cake is about 290kg), add 1000L of water and stir, then add 100kg of sodium hydroxide in batches, heat up to evaporate ethanol, and keep a small amount of reflux for 20 hours at an internal temperature above 95°C. Cool down to 20°C, filter and centrifuge, and wash the filter cake with water. Obtain about 118kg of high-...

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PUM

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Abstract

The invention relates to a preparation method of high-purity indole and belongs to the technical field of organic synthesis. The preparation method comprises: subjecting indole as a raw material to additive reaction with sodium hydrogen sulfite to obtain 2-sodium sulfonate indoline, solvent washing to remove impurities, and adding alkali for hydrolyzing to obtain the high-purity indole. The preparation method is characterized mainly in that main impurity 3-methylindole contained in indole during a reaction process never reacts with sodium hydrogen sulfite for the purpose of separating indole and 3-methylindole. Both the additive reaction and hydrolytic reaction use as water a reaction medium, a solvent is recyclable, the materials are low in cost, and yield is high.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis and relates to a preparation method of high-purity indole. Background technique [0002] Indole is an important pharmaceutical and pesticide intermediate, widely used in the production of pharmaceuticals, pesticides, dyes and other fine chemicals. Indole has a flower-like fragrance at a very low concentration, and is a component of many floral fragrances, and is widely used in the preparation of various essences. [0003] Indole compounds have a series of biological activities. It is also an important class of fine chemical products, widely used as organic, dye, pharmaceutical and pharmaceutical intermediates, and many of its derivatives have significant pharmacological activity. In clinical medicine, some of these indole derivatives have been used to treat various diseases, such as cancer, tumor, AIDS, anti-inflammatory and analgesic, viral diseases and infectious diseases. [0004] ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D209/08
CPCC07D209/08
Inventor 姜明许陈兵鲍烨华李凯顾理群
Owner NANTONG WANNIANCHANG PHARMA
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