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Method for preparing 5-bromoindole

A technology of bromoindole and indole, which is applied in the field of preparing 5-bromoindole, can solve the problems of high cost, large solvent consumption, and low atom economy, and achieve the effects of convenient operation, high product quality, and high purity

Inactive Publication Date: 2012-07-11
河南凯美克制药有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, there are many deficiencies in the production process of 5-bromoindole, such as: large solvent consumption, low atom economy, high cost, etc., and there are no relevant reports on large-scale production at home and abroad

Method used

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  • Method for preparing 5-bromoindole
  • Method for preparing 5-bromoindole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] A method for preparing 5-bromoindole, comprising the steps of:

[0025] ①Synthesis of 2-sodium sulfonate-indole: Dissolve 7.2g of indole in 80ml of ethanol, then add 52g of sodium bisulfite aqueous solution with a mass concentration of 27% (it is advisable to complete the dropwise addition within 1.5h), at 28°C After 18 hours of reaction, the reaction solution was filtered, washed, and dried to obtain 13.2 g of light blue intermediate I (the intermediate I was 2-sodium sulfonate-indole);

[0026] ②Synthesis of 2-sodium sulfonate-1-acetylindole: take 6g of intermediate I and 23g of acetic anhydride and stir and mix, then raise the temperature to 70°C for 2.5h, then add 8g of ethyl acetate to continue the reaction for 30min, cool down after the reaction To room temperature, the reaction solution was filtered, washed, and dried to obtain 5.5 g of white powder intermediate II (the intermediate II is 2-sodium sulfonate-1-acetylindole);

[0027] ③Synthesis of 5-bromoindole: ...

Embodiment 2

[0029] A method for preparing 5-bromoindole, comprising the steps of:

[0030] ① Dissolve 7.2g of indole in 86ml of isopropanol, then add dropwise 64g of potassium bisulfite aqueous solution with a mass concentration of 22%, and react at 25°C for 20h. After the reaction, the reaction solution is filtered, washed, and dried to obtain 12.4g of shallow Blue Intermediate I;

[0031] ② Stir and mix 6g of intermediate I and 27g of acetic anhydride, then raise the temperature to 73°C for 3 hours, then add 9g of ethyl propionate to continue the reaction for 1 hour, after the reaction is completed, cool to room temperature, and the reaction solution is filtered, washed and dried to obtain 5.4g White powder intermediate II;

[0032] ③Dissolve 4.8g of intermediate II in 40g of water, add 8.6g of bromine dropwise at 0°C, and keep the reaction for 1.5h, then rise to room temperature, and continue the reaction for 1h, then add 22g of 5.4% potassium bisulfite aqueous solution After reactin...

Embodiment 3

[0034] A method for preparing 5-bromoindole, comprising the steps of:

[0035] ①Dissolve 7.2g of indole in a mixture of 40ml of ethanol and 35ml of methanol, then add dropwise 64g of potassium bisulfite aqueous solution with a mass concentration of 22%, and react at 25°C for 20h. After the reaction, the reaction solution is filtered, washed, and dried 13.4g light blue intermediate I was obtained;

[0036] ② Stir and mix 6g of intermediate I and 28g of acetic anhydride, then raise the temperature to 68°C and react for 3h, then add 9g of benzene to continue the reaction for 1h, after the reaction is completed, cool to room temperature, and the reaction solution is filtered, washed, and dried to obtain 5.5g of white powder Intermediate II;

[0037] ③ Dissolve 4.8g of intermediate II in 42g of water, add 7.7g of bromine dropwise at 0°C, and keep the reaction for 1.5h, then rise to room temperature, continue the reaction for 1h, and then add 20g of 7% potassium bisulfite aqueous s...

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Abstract

The invention relates to a method for synthesizing 5-bromoindole. The method comprises the following steps of: (1) dissolving indole into alcoholic organic solvents, adding an aqueous solution of sodium hydrogensulfite or potassium hydrogensulfite, reacting for 15 to 20h, filtering a reaction solution, washing, and drying to obtain an intermediate I; (2) mixing the intermediate I and acetic anhydride, raising the temperature to 68 to 75 DEG C, reacting for 2 to 3h, adding ester or benzene organic solvents, reacting for 0.5 to 1h, cooling to room temperature after the reaction is finished, filtering, washing, and drying to obtain an intermediate II; and (3) dissolving the intermediate II into water, adding bromine at the temperature of between 0 and 5 DEG C, keeping the reaction for 1 to 3h, raising to room temperature, continuing to react for 1 to 2h, adding the aqueous solution of sodium hydrogensulfite or potassium hydrogensulfite, reacting for 10 to 30min, adding an aqueous solution of sodium hydroxide or potassium hydroxide, refluxing for 12 to 18h, cooling a reaction solution, precipitating crystals, filtering, washing, and drying to obtain a product, namely the 5-bromoindole. The method is low in cost consumption and is simple, and the quality of the product is high.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a method for preparing 5-bromoindole. Background technique [0002] 5-Bromoindole is an important pharmaceutical intermediate and an important raw material for the production of drugs to prevent and treat cardiovascular diseases, neurological diseases, tumors and enhance immunity. One of its important uses is to synthesize indole derivatives, such as: color amine compounds, etc. These indole derivatives are closely related to human life activities, among which melatonin and its derivatives are very effective in regulating circadian rhythm, sleep, anti-tumor, etc.; Cancer effect; 5-hydroxytryptamine is an important neurotransmitter and an indispensable substance to maintain the normal activities of human spirit and thinking. It is mainly produced by tryptophan metabolism in the human body. When the amount of 5-hydroxytryptamine in the human brain suddenly When it changes, neurol...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D209/08
Inventor 武小军刘应凡郝家金杨广远
Owner 河南凯美克制药有限公司
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