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Method for synthesizing 2, 6-diaminotoluene

A technology of diaminotoluene and nitrotoluene, which is applied in the field of synthesizing 2,6-diaminotoluene, can solve the problems of high reaction temperature, equipment corrosion, and low yield, and achieve good reaction selectivity, less by-products, and high yield. high rate effect

Active Publication Date: 2015-06-24
ZHEJIANG DINGLONG TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Among them, the yield of 2,6-dinitrotoluene is about 45% through the two-step reaction of trinitrotoluene solvent reduction and diazo deamination method, which is low, and the raw material trinitrotoluene is too dangerous, and there are Large potential safety hazard; the use of p-toluenesulfonic acid nitrification hydrolysis process has the problem of high reaction temperature and serious equipment corrosion. The nitrification temperature is 110-115 ° C, and the hydrolysis temperature is 170 ° C. The process corrodes the equipment seriously and the production safety is poor. , producing more three wastes; the nitration reduction of toluene will obtain a mixture of 2,4-dinitrotoluene and 2,6-dinitrotoluene, and there are certain difficulties in separation due to the close properties of the two; Separation and purification methods such as crystallization, trichlorethylene recrystallization, dilute nitric acid recrystallization, concentrated sulfuric acid recrystallization, and complex recrystallization all have problems such as difficult separation, low yield, and large wastes.
Therefore, there are great difficulties in the source of 2,6-dinitrotoluene

Method used

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  • Method for synthesizing 2, 6-diaminotoluene

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] (1) Reduction reaction: put a certain amount of 2-chloro-6-nitrotoluene 50g, Raney nickel 1g, dicyandiamide 0.05g, methanol 79g in a 250ml autoclave, seal the kettle, stir, nitrogen replacement three times, hydrogen replacement Three times, fill with hydrogen to 0.2MPa, take a sample after reacting at 50°C for 4 hours, until the raw material 2-chloro-6-nitrotoluene is completely reacted; filter the reaction solution to remove the catalyst, and recover methanol under reduced pressure to obtain 3-chloro-2-methanol The crude product of phenylaniline, the crude product obtained 37g of pure 3-chloro-2-methylaniline after vacuum distillation (yield 90%), GC>99%;

[0028] (2) Ammonolysis reaction: 20g of 3-chloro-2-methylaniline, 5g of cuprous chloride, 75g of 25% ammonia water, 2g of urea were put into a 250ml autoclave, the kettle was sealed, stirred, heated to 160°C, and the pressure was 2.3 MPa, take a sample after 20 hours of reaction until the raw material 3-chloro-2-met...

Embodiment 2

[0030] (1) Reduction reaction: drop into 2-chloro-6-nitrotoluene 50g in 250ml autoclave, Raney nickel 1g, dicyandiamide and morpholine compound 0.05g, the weight ratio of dicyandiamide and morpholine is 1 : 0.5, ethanol 79g, seal the kettle, stir, nitrogen replacement three times, hydrogen replacement three times, fill hydrogen to 0.1MPa, take a sample after reacting at 30°C for 4 hours, until the raw material 2-chloro-6-nitrotoluene is completely reacted; The catalyst was removed by filtration, and ethanol was recovered under reduced pressure to obtain a crude product of 3-chloro-2-methylaniline, which was 38 g (yield 92.5%) after vacuum distillation, GC>99%;

[0031] (2) Ammonolysis reaction: 20g of 3-chloro-2-methylaniline, 5g of cuprous oxide, 75g of 10% ammonia solution, 2g of benzaldehyde are put into a 250ml autoclave, the kettle is sealed, stirred, heated to 180°C, and the pressure is 3.0MPa, take a sample after 20 hours of reaction until the raw material 3-chloro-2-me...

Embodiment 3

[0033](1) Reduction reaction: drop 2-chloro-6-nitrotoluene 50g in 250ml autoclave, Raney nickel 1g, dicyandiamide and tributyl phosphate compound 0.05g, dicyandiamide and tributyl phosphate compound The weight ratio is 1:0.5, isopropanol 79g, seal the kettle, stir, replace with nitrogen three times, replace with hydrogen three times, fill with hydrogen to 0.2MPa, react at 40°C for 3 hours and take a sample until the raw material 2-chloro-6-nitrotoluene The reaction was complete; the reaction solution was filtered to remove the catalyst, and the isopropanol was recovered under reduced pressure to obtain the crude product of 3-chloro-2-methylaniline, which was 37 g (yield 90%) after vacuum distillation, GC>99%;

[0034] (2) Ammonolysis reaction: 20g of 3-chloro-2-methylaniline, 5g of copper oxide, 75g of 25% ammonia solution, 2g of urotropine are put into a 250ml autoclave, the kettle is sealed, stirred, heated to 150°C, and the pressure At 2MPa, take a sample after reacting for...

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Abstract

The invention relates to a method for synthesizing 2, 6-diaminotoluene. The method comprises the following step: by using 2-chlorine-6-nitrotoluene as a raw material, carrying out reduction reaction and ammonolysis reaction to obtain 2, 6-diaminotoluene. The process is simple in synthesis route, easy to control the reaction and few in three wastes generated at the working segments, thereby meeting the green and environmental friendly requirements; and moreover, produced 2, 6-diaminotoluene is high in purity and excellent in quality, so that the method is an excellent industrial route.

Description

technical field [0001] The invention relates to a method for synthesizing 2,6-diaminotoluene. Background technique [0002] 2,6-diaminotoluene is an important chemical intermediate, which can be used in the synthesis of flexible polyurethane foam plastics, coatings, rubber and adhesives. 2,6-diaminotoluene can also be used as a dye intermediate. for the synthesis of various dyes. [0003] There have been many researches on the preparation method of 2,6-diaminotoluene. At present, the preparation method of 2,6-diaminotoluene is mainly prepared by reducing 2,6-dinitrotoluene. The specific method is to obtain 2,6-diaminotoluene by hydrogenation reduction of 2,6-dinitrotoluene in the presence of a catalyst; and the known and reported preparation method of 2,6-dinitrotoluene is trinitrotoluene reduction diazonium method , p-toluenesulfonic acid nitration hydrolysis method, toluene nitration mixture separation method three methods. Among them, the yield of 2,6-dinitrotoluene is...

Claims

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Application Information

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IPC IPC(8): C07C211/51C07C209/10
Inventor 秦振伟刘琛施云龙潘志军朱书荣朱翼鸣
Owner ZHEJIANG DINGLONG TECH
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