Preparation method of bromo-nitroaniline dye stuff intermediate

A technology for dye intermediates and nitroaniline is applied in the field of synthesis of bromonitroaniline dye intermediates, can solve the problems of high cost, high cost of bromine, large amount of sodium hypochlorite, etc., and achieves good quality and complete bromination reaction. , the effect of reducing production costs

Active Publication Date: 2010-09-22
浙江长征化工有限公司
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Problems solved by technology

Using sodium hypochlorite as an oxidizing agent will not be able to participate in the reaction of Br - to Br + , the utilization rate of bromine in the normal bromination reaction is increased from 50% to more than 90%, and the production cost is lower than direct bromination, but using bromine and sodium hypochlorite as raw materials, the cost of bromine is high, and the amount of sodium hypochlorite is large. Also high, 2-cyano-4-nitro-6-bromoaniline product cost is also higher

Method used

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  • Preparation method of bromo-nitroaniline dye stuff intermediate

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Embodiment 1

[0021] In a 5000L still, add 4000L of solution containing potassium bromide (concentration of 7.5% by mass in terms of bromide ions), distill 2000L of water through distillation, add 20 kg of active carbon, decolorize and filter, then add flocculant and other precipitation and filter to obtain the concentration Be 15% (mass percent concentration in terms of bromide ions) potassium bromide solution;

[0022] In the enamel reaction kettle of 5000L, add the potassium bromide solution 2735kg that the concentration that recovers is 15% (mass percentage concentration in terms of bromide ion), slowly add 480kg of 98% sulfuric acid, stir for 30 minutes, drop into 2,4-di Nitroaniline 880kg, and be warming up to 35 ℃, slowly add the concentration that has been prepared dropwise and be 540kg of 30% sodium chlorate solution, add, keep warm for half an hour, heat up to 75 ℃, keep warm for 2 hours, cool to room temperature, Filtrate, wash the filter cake with water until the pH value is 5-8...

Embodiment 2

[0024] The hydrobromic acid obtained by absorbing the waste gas containing hydrogen bromide through multi-stage water absorption or falling film absorption is used as the bromination raw material for standby when the bromide ion content in the hydrobromic acid solution reaches 20%.

[0025] In a 5000L enamel reaction kettle, add 2050kg of hydrobromic acid solution with a prepared concentration of 20% (mass percentage concentration in terms of bromide ions), slowly add 490kg of 98% sulfuric acid, stir for 30 minutes, and drop 2,4 -Dinitroaniline 880kg, and heat up to 40°C, slowly add 552kg of 30% sodium chlorate solution dropwise, after adding, keep warm for half an hour, heat up to 70°C, keep warm for 2 hours, and cool to room temperature , filtered, the filter cake was washed with water until the pH value was 5-8, and dried to obtain 1240 kg of bright yellow 2,4-dinitro-6-bromoaniline, with a yield of 98% and a product purity of ≥98%.

Embodiment 3

[0027] Add 4000L of sodium bromide solution with a concentration of 9% (mass percentage concentration in terms of bromide ions) in a 5000L distillation kettle, distill 1000L of water, add 15 kg of activated carbon, decolorize and filter, then add flocculants and other precipitation and filter Obtaining the potassium bromide solution that obtaining concentration is 15% (mass percent concentration in bromide ion);

[0028] In a 5000L enamel reaction kettle, add 1425kg of recovered 12% sodium bromide solution (mass percentage concentration in terms of bromide ions), slowly add 333kg of 98% sulfuric acid, stir for 30 minutes, and drop in 2-cyano-4 - Nitroaniline 326kg, and heat up to 43°C, slowly add 300kg of sodium chlorate solution with a concentration of 25% dropwise, after adding, keep warm for half an hour, heat up to 70°C, keep warm for 2 hours, and cool to room temperature , filtered, the filter cake was washed with water until the pH value was 5-8, and dried to obtain 480 ...

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Abstract

The invention discloses a preparation method of a bromo-nitroaniline dye stuff intermediate, which comprises the following steps of: adding inorganic acid aqueous solution into bromide aqueous solution; stirring the mixture; adding a nitroaniline compound into the mixture; raising the temperature of the mixture to be between 35 and 55 DEG C; pulping and stirring the mixture; dropping chlorate aqueous solution into the mixture, wherein the dropping time is more than 2 hours; stirring the mixture, and raising the temperature of the mixture to between 65 and 75 DEG C; filtering the mixture after reaction; washing a filter cake until the pH value is 5 to 8; and drying the filter cake to obtain the bromo-nitroaniline dye stuff intermediate. The product obtained by adopting the method has high quality and yield, the production cost is greatly reduced, the process is simple, and simultaneously, the pollution, caused by waste gases containing hydrogen bromide and waste water containing bromide salts, to the environment is greatly cut down.

Description

technical field [0001] The invention belongs to the field of preparation of dye intermediates, in particular to a synthesis method of bromonitroaniline dye intermediates. Background technique [0002] In the current technology, the amount of bromonitroaniline dye intermediates is relatively large. The existing production method is obtained by bromination of nitroaniline (2,4-dinitroaniline, p-nitroaniline, o-chloro-p-nitroaniline, o-cyano-p-nitroaniline, etc.) as raw materials. In general bromination, the utilization rate of bromine molecules is only 50%, that is, Br + , the other half Br - Lost from waste water (P134, "Organic Chemistry Experiment", edited by Lanzhou University, Department of Chemistry, Fudan University, Department of Organic Chemistry, Second Edition, Beijing: Higher Education Press, 1994.4), its manufacturing cost is relatively high, and causes serious environmental problems pollute. [0003] It is proposed in the patent document CN01106584.2 that the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07B39/00C07C211/52C07C209/74C07C255/58C07C253/30
Inventor 金永辉阮国涛赵锋莫琰杜伟丰
Owner 浙江长征化工有限公司
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