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Method for producing N- ethyl carbazole

A technology of ethyl carbazole and carbazole, applied in the field of synthesizing N-ethyl carbazole, can solve the problems of complex production process, high cost, long reaction time, etc., achieve high yield and content, low production cost, easy operation easy effect

Inactive Publication Date: 2008-12-24
BAOSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] 3. Ethyl p-toluenesulfonate method: This method has higher cost, longer reaction time, and produces potassium p-toluenesulfonate by-product
In the above three documents, the strong alkali aqueous solution-benzene two-phase system is used. After the reaction, the layers must be statically separated, and the product in the extracted water layer is incorporated into the upper oil layer, and then the benzene in the oil layer is evaporated. The product N-ethylcarbazole is obtained by recrystallization, and the whole production process is relatively complicated

Method used

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  • Method for producing N- ethyl carbazole
  • Method for producing N- ethyl carbazole

Examples

Experimental program
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Effect test

Embodiment 1

[0034] Put 300kg of toluene into the reaction kettle, add 100kg of 96% carbazole, 120kg of KOH and 1.5kg of benzyltriethylammonium chloride, start to stir and add 80kg of bromoethane dropwise for 45 minutes, and heat to 80°C Post-reaction for 5 hours. The mother liquor after the reaction was moved to a distillation pot, the solvent toluene was evaporated, and absolute ethanol was added for recrystallization, filtered and dried to obtain 99.74% N-ethylcarbazole.

[0035] The yield of N-ethylcarbazole was 98.3%.

[0036] After the KOH used after the reaction was washed with mixed xylenes, the above operation was repeated, and the yield of N-ethylcarbazole was 97.5%.

Embodiment 2

[0038]Add 8.3g carbazole, 0.1g catalyst benzyltriethylammonium chloride, 25g toluene, and 10g potassium hydroxide into a three-necked flask equipped with a reflux condenser, a thermometer, and a magnetic stirrer, heat in a water bath, and dropwise add Bromoethane 7g, dropwise for 30 minutes, heated to 75°C and reacted for 3h. The reaction was stopped, the solvent toluene in the reaction mother liquor was evaporated, methanol was added to recrystallize the product, and 99.86% N-ethylcarbazole was obtained by filtration.

[0039] The yield of N-ethylcarbazole was 98.1%.

[0040] After the KOH used after the reaction was washed with mixed xylenes, the above operation was repeated, and the yield of N-ethylcarbazole was 97.7%.

Embodiment 3

[0042] Put 400kg of toluene into the reaction kettle, add 100kg of 97% carbazole, 150kg of KOH and 2kg of benzyltriethylammonium chloride, start to stir and add 85kg of bromoethane dropwise for 45 minutes, after heating to 85°C React for 4 hours. Move the reacted mother liquor to a distillation pot, evaporate the solvent toluene, add 95% ethanol solution for recrystallization, filter and dry to obtain 99.68% N-ethylcarbazole.

[0043] The yield of N-ethylcarbazole was 98.8%.

[0044] After the KOH used after the reaction was washed with mixed xylenes, the above operation was repeated, and the yield of N-ethylcarbazole was 98.2%.

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Abstract

The invention provides a method for producing N-ethyl carbazole. The method takes toluene as a solvent, and utilizes benzyl triethyl ammonium chloride as a phase transfer catalyst and takes solid KOH as a deproton agent. Carbazole and ethyl bromide react to produce the N-ethyl carbazole. The method for producing N-ethyl carbazole has simple process, is easy to realize the continuous process, can reuse the catalyst of the solid KOH and has the yield of the product up to more than 97 percent.

Description

technical field [0001] The invention relates to the field of dye chemical industry, in particular, the invention relates to a method for synthesizing N-ethylcarbazole. Background technique [0002] N-Ethylcarbazole is an intermediate for the synthesis of dye vat blue GNX and pigment permanent violet RL. Permanent Violet RL, the dye index number is C.I Pigment Violet 23, has the characteristics of high tinting strength and bright color, and its heat resistance, light resistance, chemical resistance, oil penetration resistance and migration are very excellent, and it is widely used in coatings, Puree dyeing of inks, rubber, plastics and synthetic fibers, is currently one of the most expensive pigments in the world and the best purple pigment used so far in the plastics industry. [0003] At present, the methods for industrially synthesizing N-ethylcarbazole generally have the following types: [0004] 1. Ethyl chloride method: carbazole reacts with potassium hydroxide at 270...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D209/86
Inventor 孙剑李乃民周杰
Owner BAOSHAN IRON & STEEL CO LTD
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