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Preparation method of high-purity 3,6-dibromo-carbazole

A dibromocarbazole, high-purity technology is applied in the field of preparation of high-purity 3,6-dibromocarbazole, can solve the problems of many by-products, high toxicity, long reaction time, etc., achieves easy operation and control, is beneficial to Industrial production, the effect of shortening the reaction time

Inactive Publication Date: 2016-04-27
SHANGHAI HUAXIAN NEW MATERIAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The disadvantages of these methods are long reaction time, many by-products, and high toxicity.

Method used

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  • Preparation method of high-purity 3,6-dibromo-carbazole
  • Preparation method of high-purity 3,6-dibromo-carbazole
  • Preparation method of high-purity 3,6-dibromo-carbazole

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Embodiment 1

[0018] The detailed steps of the present invention are as follows: wherein, the feeding amount is as follows: carbazole: 167.2g, dibromohydantoin: 285.8g, absolute ethanol: 1800ml. Add 167.2g of carbazole (1mol) and 1000ml of absolute ethanol into a 2000ml reaction bottle, stir for 20 minutes to disperse evenly. Then add 285.8 g of dibromohydantoin in batches, control the reaction temperature at 20-25° C., and complete the addition in about 2 hours. After the addition, a large amount of white solids will precipitate out. Reaction was continued at this temperature for 1 hour. Use HPLC to monitor the reaction. When the monobrominated product in the reaction solution is less than 1%, stop the reaction and filter at 20-25°C. Add the filter cake to a 1000ml three-necked flask, then add 800ml of absolute ethanol, heat to reflux (80°C) for 1 hour, then slowly cool down to 20-25°C, filter, and dry under normal pressure at 100°C to obtain 310g of white powdery solid . Such as figur...

Embodiment 2

[0024] The detailed steps of the present invention are as follows: wherein, the feeding amount is as follows: carbazole: 167.2g, dibromohydantoin: 300.1g, absolute ethanol: 1800ml.

[0025] Add 167.2g of carbazole (1mol) and 1000ml of absolute ethanol into a 2000ml reaction bottle, stir for 20 minutes to disperse evenly. Then add 285.8 g (1.05 mol) of dibromohydantoin in batches, control the reaction temperature at 20-25°C, and complete the addition in about 2 hours. After the addition, a large amount of white solid will precipitate. Reaction was continued at this temperature for 1 hour. Use HPLC to monitor the reaction. When the monobrominated product in the reaction solution is less than 1%, stop the reaction and filter at 20-25°C. Add the filter cake to a 1000ml three-necked flask, then add 800ml of absolute ethanol, heat to reflux (80°C) for 1 hour, then slowly cool down to 20-25°C, filter, and dry under normal pressure at 100°C to obtain 312g of white powdery solid . S...

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Abstract

The present invention discloses a preparation method of high-purity 3,6-dibromo-carbazole. The preparation method comprises the following steps: carbazole and absolute ethyl alcohol are added into a container, and dibromodimethyl hydantoin is added into the container in batches at room temperature; a reaction is stopped until no monobromination product is detected by HPLC spectrum; and crude products can be obtained by a direct filtration; and the crude products are subjected to hot ethanol reflux, cooling treatment and additional filtration, thereby obtaining white crystalline solid products. The preparation method uses the absolute ethyl alcohol as a solvent, improves the production and operation environment, uses cheap dibromodimethyl hydantoin as a brominating agent at the same time, can synthesize the high-purity 3,6-dibromo carbazole under the condition of normal temperature, avoids bromine production, is easy to operate and control, shortens reaction time, reduces costs, and is beneficial to industrial production.

Description

technical field [0001] The invention relates to a preparation method of dibromocarbazole, in particular to a preparation method of high-purity 3,6-dibromocarbazole. Background technique [0002] Carbazole and its derivatives are a class of heterocyclic aromatic compounds with large π-electron conjugated system and strong intramolecular electron transfer characteristics, excellent photoelectric properties, and are widely used in the fields of dyes, pigments, spices, medicines and pesticides . 3,6-Dibromocarbazole is a very important intermediate for the synthesis of N-alkylated bromocarbazole compounds, and is widely used in medicine and organic photoconductive materials. At present, the main synthesis methods are: potassium bromide and potassium bromate mixed method, chloranil dehydrogenation method of diazonium salt method, sulfonation method, BNS method, and bromine bromination method. The disadvantages of these methods are long reaction time, many by-products and high t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D209/88
Inventor 吴跃初宋文志吴章超
Owner SHANGHAI HUAXIAN NEW MATERIAL TECH CO LTD
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