Synthetic method and application of disperse dye intermediate

Abstract

The invention provides a synthetic method and application of a disperse dye intermediate, and relates to the technical field of dyes. According to the disperse dye intermediate synthesis method, m-aminoacetanilide and chloroethane are subjected to an alkylation reaction, filtrate is an ammonium chloride solution after an alkylation product is crystallized, ammonium chloride as a byproduct is concentrated after decoloration, and the step is applied after a water phase is condensed; the layered water phase is ammonium sulfate and an ammonium acetate solution, decoloring and concentrating to obtain a byproduct ammonium fertilizer, and applying the step after the water phase is condensed. The obtained salt crystals are sodium chloride and a small amount of sodium carbonate and sodium bicarbonate salt crystals which are not completely reacted, the salt crystals are dissolved with water and neutralized into a sodium chloride solution with hydrochloric acid, a byproduct sodium chloride is concentrated after decoloration, and the step is applied after a water phase is condensed. And recycling the solvent by distillation, and applying the raw materials to the step. The method has the advantages of mild reaction conditions, low equipment requirements and high process safety; product conversion rate is high, and raw material cost is low; three wastes are easy to treat, environment-friendly treatment cost is low, and pollution is small.

Description

Technical Field

[0001] The invention relates to the technical field of dyes, and in particular to a method for synthesizing a disperse dye intermediate and application thereof. Background Art

[0002] Disperse dyes are an important class of chemical raw materials, widely used in textile, printing and dyeing and other fields. Their performance and stability are directly related to the quality of the final product. In the production process of disperse dyes, the synthesis of intermediates is a crucial link, which is directly related to the performance and cost of the dyes. Among them, 3-(N,N-diethyl)amino-N-methylsulfonylaniline is a key intermediate for synthesizing advanced disperse dyes such as Disperse Red F3BS, and its synthesis method has always received great attention from the industry.

[0003] Specifically, in the alkylation step of the traditional method, whether using diethyl sulfate, ethyl bromide or ethyl chloride, there are problems such as high cost, high pollution and low conversion rate. In particular, the diethyl sulfate process has been gradually eliminated due to its extremely low atomic utilization rate and serious pollution of three wastes; while the ethyl bromide process has high project investment and operation costs due to the scarcity of bromine resources, high raw material costs, difficulty in recovery and high equipment requirements.

[0004] In order to overcome the shortcomings of the above-mentioned traditional methods, the present invention proposes a new method for synthesizing 3-(N,N-diethyl)amino-N-methylsulfonylaniline, which realizes the efficient synthesis of the target product. Summary of the invention

[0005] The purpose of the present invention is to provide a disperse dye intermediate synthesis method and application thereof, which can realize the efficient synthesis of the target product.

[0006] The present invention solves the technical problem by adopting the following technical solutions.

[0007] The present invention provides a method for synthesizing a disperse dye intermediate, comprising the following steps:

[0008] The m-aminoacetanilide is subjected to an alkylation reaction with ethyl chloride, and ammonia water is used as an acid-binding agent to obtain 3-(N,N-diethylamino)acetanilide, which is cooled and crystallized and then filtered. The chemical equation is as follows:

[0009]

[0010] The obtained 3-(N,N-diethylamino)acetanilide is refluxed and hydrolyzed in 30-50% dilute sulfuric acid for 3-5 hours, and the hydrolyzate is neutralized with ammonia water at a temperature below 20°C. The aqueous phase is removed by layering to obtain an oil phase, i.e., 3-(N,N-diethylamino)aniline. The chemical equation is as follows:

[0011]

[0012] The obtained 3-(N,N-diethylamino)aniline was dissolved in methanol, sodium carbonate was added as an acid binding agent, and excess methylsulfonyl chloride was added dropwise at low temperature to react. The reaction system was a homogeneous solution, and the chemical equation was expressed as follows:

[0013]

[0014] After the reaction, the salt crystals are removed by filtration, and the solvent and raw materials are recovered by rotary evaporation and reduced pressure distillation to obtain the target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline.

[0015] In some embodiments, the alkylation reaction is carried out at a reaction pressure of 0.3-0.8 MPa and a reaction temperature of 90-100°C.

[0016] In some embodiments, the alkylation reaction is carried out at a reaction pressure of 0.75 MPa and a reaction temperature of 92.5 °C.

[0017] In some embodiments, the following steps are also included:

[0018] The target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline is distilled to obtain a product with a purity of more than 98%.

[0019] The present application further provides 3-(N,N-diethyl)amino-N-methylsulfonylaniline prepared by a method for synthesizing a disperse dye intermediate.

[0020] The present application further provides an application of a disperse dye intermediate synthesis method in dye production.

[0021] The method for synthesizing disperse dye intermediates of the embodiment of the present invention uses ethyl chloride for alkylation reaction. After the alkylation product is crystallized, the filtrate is an ammonium chloride solution. After decolorization, the by-product ammonium chloride is concentrated. After the aqueous phase is condensed, this step is applied; the stratified aqueous phase is ammonium sulfate and ammonium acetate solution. After decolorization, the by-product ammonium fertilizer is concentrated. After the aqueous phase is condensed, this step is applied. The obtained salt crystals are sodium chloride and a small amount of unreacted sodium carbonate and sodium bicarbonate salt crystals. After being dissolved in water, they are neutralized with hydrochloric acid to form a sodium chloride solution. After decolorization, the by-product sodium chloride is concentrated. After the aqueous phase is condensed, this step is applied. The solvent and raw materials are distilled and recovered. The invention has mild reaction conditions, low equipment requirements, and high process safety; high product conversion rate, low raw material cost; easy treatment of three wastes (by-product industrial salt, water reuse), low environmental protection treatment costs, and low pollution. It has extremely high industrial value. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0023] The following is a detailed description of a method for synthesizing a disperse dye intermediate and its application in accordance with an embodiment of the present invention.

[0024] The embodiment of the present invention provides a disperse dye intermediate, and its molecular structure general formula is:

[0025]

[0026] (N,N-diethyl)amino-N-methylsulfonylaniline is the main intermediate for the synthesis of Disperse Red F3BS. The conventional synthesis method is:

[0027] In the related art, m-phenylenediamine is used as a raw material, and acylated with benzoyl chloride under weak alkaline conditions in an ice-water solution, and then m-amino-N-methylsulfonylaniline is obtained after filtration and washing.

[0028] The reaction system of this step is a large amount of ice water, and the reaction process needs to keep the methylsulfonyl chloride in excess. After the reaction, the intermediate product m-amino-N-methylsulfonylaniline is obtained by filtration and washing. Since the excess methylsulfonyl chloride is brought into the water phase, the product separation mother liquor contains highly toxic methylsulfonyl chloride, sodium chloride and unreacted raw material by-products, etc., which makes the wastewater treatment cost high and the effect poor.

[0029] The alkylation reaction of m-amino-N-methylsulfonylaniline gives 3-(N,N-diethyl)amino-N-methylsulfonylaniline. There are three routes for the alkylation:

[0030] The first one: reaction with diethyl sulfate;

[0031] The second type: reflux reaction with ethyl bromide;

[0032] The third method: using solvents such as methanol to react with ethyl chloride under pressure (1.5-2.0Mpa);

[0033] In the above routes: if the diethyl sulfate process is adopted, the atomic utilization rate of diethyl sulfate is extremely low, the three wastes are polluted, and the cost is high. If the ethyl bromide process is adopted, due to the scarcity of bromine resources, the cost of raw material ethyl bromide is high, the recovery of bromine resources is highly corrosive, the equipment requirements are high, and the project investment and operation costs are high. If the ethyl chloride process is adopted, it is a relatively green process, but the raw material m-amino-N-methylsulfonylaniline in this step is almost insoluble in water. There is literature on high-temperature dissolution in a methanol system, the reaction temperature is 120-130°C, and the reaction pressure is up to 2.0Mpa. Due to the heterogeneous system, the engineering effect is poor and the conversion rate is low.

[0034] To this end, the present invention provides a method for synthesizing a disperse dye intermediate, comprising the following steps:

[0035] The m-aminoacetanilide is subjected to an alkylation reaction with ethyl chloride, and ammonia water is used as an acid-binding agent to obtain 3-(N,N-diethylamino)acetanilide, which is cooled and crystallized and then filtered. The chemical equation is as follows:

[0036]

[0037] According to one embodiment, the obtained m-aminoacetanilide is subjected to an alkylation reaction with ethyl chloride, and aqueous ammonia is used as an acid-binding agent to obtain 3(N,N-diethylamino)acetanilide, and the reaction is filtered after cooling and crystallization, comprising:

[0038] The reaction is carried out under a pressure of 0.3 to 0.8 MPa;

[0039] Control the reaction temperature between 90 and 100°C;

[0040] During the reaction, ammonia water was used to maintain pH ≥ 4.5;

[0041] The reaction was stopped when the ethyl chloride in the reactants was completely consumed.

[0042] In this step, we choose ethyl chloride as the alkylating agent instead of traditional diethyl sulfate or ethyl bromide because ethyl chloride has lower cost and produces less waste. The alkylation reaction is carried out in an autoclave, the reaction pressure is set at 0.75MPa, and the reaction temperature is controlled at 92.5℃. In order to improve the reaction efficiency, we use ammonia water as an acid binding agent to neutralize the acidic substances generated during the reaction. At the beginning of the reaction, m-aminoacetanilide is dissolved in a suitable proportion of water, and then ethyl chloride and an equal proportion of ammonia water are slowly added under stirring. After the reaction is completed, a solid product can be obtained by cooling to room temperature and filtering. For example, if we use 1 mole of m-aminoacetanilide in the reaction, then theoretically 1 mole of 3-N,N-diethylaminoacetanilide can be obtained. In this way, we not only reduce the cost of raw materials, but also reduce the burden of wastewater treatment and improve the conversion rate.

[0043] According to one embodiment, the obtained 3(N,N-diethylamino)acetanilide is refluxed and hydrolyzed in 30-50% dilute sulfuric acid for 3-5 hours, the hydrolyzate is neutralized with ammonia water at a temperature below 50° C., and the aqueous phase is removed by layering to obtain an oil phase, namely 3(N,N-diethylamino)aniline, comprising:

[0044] The hydrolysis reaction was carried out in 35% dilute sulfuric acid;

[0045] The hydrolysis time was controlled to be 4 hours;

[0046] When the acid value of the hydrolyzate stabilizes to 20-25%, neutralize with ammonia water after cooling down;

[0047] Stop adding ammonia water when the pH value reaches 7±5.

[0048] The obtained 3-(N,N-diethylamino)acetanilide is refluxed and hydrolyzed in 30-50% dilute sulfuric acid for 3-5 hours, and the hydrolyzate is neutralized with ammonia water at a temperature below 50°C. The aqueous phase is removed by layering to obtain an oil phase, i.e., 3-(N,N-diethylamino)aniline. The chemical equation is as follows:

[0049]

[0050] Here, according to the provided 3-(N, N-diethylamino) acetanilide, 30-50% dilute sulfuric acid is used for hydrolysis reaction. By setting a reaction container, uniform mixing is ensured, and the reaction time is controlled to be completed within 3-5 hours. The reaction temperature is monitored by a temperature sensor and maintained within the specified reaction temperature range. The acid value of the hydrolyzate is monitored by an acid value sensor. When the acid value reaches the preset condition, ammonia water is used for neutralization after cooling. The oil phase and the water phase are separated from the hydrolyzate by a layering technique to obtain 3-(N, N-diethylamino) aniline in the oil phase. The purity and concentration of 3-(N, N-diethylamino) aniline in the oil phase are detected by a chemical analysis instrument. The chemical composition of the oil phase is analyzed by a data processing system to confirm whether it meets the quality standards. The reaction parameters are adjusted by an automated control system to optimize the production process and improve the yield of 3-(N, N-diethylamino) aniline. The environmental monitoring system is used to ensure environmental safety during the production process and prevent the leakage of harmful substances. The storage and transportation of 3-(N, N-diethylamino) aniline are arranged by a logistics management system to ensure that the product quality is not affected.

[0051] Specifically, in the process of implementing the hydrolysis reaction of 3-(N, N-diethylamino)acetanilide, a glass reactor with a volume of 500 liters is first set up to ensure that it has an efficient stirring device to achieve uniform mixing of 30-50% dilute sulfuric acid and raw materials. The reactor is equipped with a temperature sensor to monitor the reaction temperature in real time, and automatically adjust the heating or cooling system through the PID algorithm to maintain the temperature within the range of 85±5°C to ensure that the reaction is carried out under optimal temperature conditions. The reaction time is set to 3-5 hours by the PLC control system, and the system automatically terminates the reaction according to the preset time. During the hydrolysis process, the acid value sensor monitors the acid value of the hydrolyzate in real time, and the data is transmitted to the central control system. When the acid value drops to the 20-25% range and stabilizes, the system automatically starts the cooling device to the material temperature below 50°C, and the ammonia addition device is turned on. Ammonia is slowly added at a rate of 1 liter / minute until the pH value is adjusted to 7.0±2, and the neutralization reaction is completed. The neutralized mixed liquid enters the separator, and the oil phase and the water phase are effectively separated by centrifugal separation technology using a centrifugal force of 3000 rpm. The oil phase is rich in 3-(N,N-diethylamino)aniline.

[0052] By reflux hydrolyzing the obtained 3-N,N-diethylaminoacetanilide in 30-50% dilute sulfuric acid for 3-5 hours, we achieved an effective conversion from acetyl to amino. In this step, we dissolved 3-N,N-diethylaminoacetanilide in 30-50% dilute sulfuric acid and heated it under reflux conditions for 3-5 hours. After the hydrolysis was completed, the reaction mixture was cooled to below 50°C and neutralized with ammonia water until the pH value reached neutral. Through the layering operation, the aqueous phase can be easily separated from the oil phase to obtain 3-N,N-diethylaminoaniline. For example, if we have 1 mole of 3-N,N-diethylaminoacetanilide, then theoretically we can get 1 mole of 3-N,N-diethylaminoaniline. In this way, we not only simplified the process flow, but also improved the purity of the product.

[0053] The obtained 3-(N,N-diethylamino)aniline was dissolved in methanol, sodium carbonate was added as an acid binding agent, and excess methylsulfonyl chloride was added dropwise at low temperature to react. The reaction system was a homogeneous solution, and the chemical equation was expressed as follows:

[0054]

[0055] According to one embodiment, the obtained 3(N,N-diethylamino)aniline is dissolved in methanol, sodium carbonate is added as an acid binding agent, and a slightly excess amount of methylsulfonyl chloride is added dropwise at low temperature to react, and the reaction system is a homogeneous solution, comprising:

[0056] When methanol dissolves 3(N,N-diethylamino)aniline, the mass ratio of methanol to 3(N,N-diethylamino)aniline is 2:1;

[0057] The amount of sodium carbonate added is twice the mole of 3(N,N-diethylamino)aniline;

[0058] The low temperature is controlled at 5℃;

[0059] Stop adding dropwise when 3(N,N-diethylamino)aniline in the reaction system is completely consumed.

[0060] By dissolving the obtained 3-N,N-diethylaminoaniline with methanol, adding sodium carbonate as an acid-binding agent, and dropping excess methylsulfonyl chloride at low temperature for reaction, we finally obtained the target product 3-N,N-diethylamino-N-methylsulfonylaniline. In this step, we first dissolved 3-N,N-diethylaminoaniline in methanol and added sodium carbonate as an acid-binding agent. Then, under low temperature conditions, a slightly excess amount of methylsulfonyl chloride was slowly added dropwise. After the reaction is completed, the generated salt crystals are removed by filtration, and the solvent and raw materials are recovered by rotary evaporation and reduced pressure distillation to obtain the target product. For example, if we have 1 mole of 3-N,N-diethylaminoaniline, then theoretically 1 mole of 3-N,N-diethylamino-N-methylsulfonylaniline can be obtained. In this way, we not only improve the conversion rate, but also reduce the generation of by-products and reduce the cost of wastewater treatment.

[0061] After the reaction, the salt crystals are removed by filtration, and the solvent and raw materials are recovered by rotary evaporation and reduced pressure distillation to obtain the target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline.

[0062] According to one embodiment, after the reaction, the salt crystals are removed by filtration, and the solvent and raw materials are recovered by rotary evaporation and reduced pressure distillation to obtain the target product 3 (N, N diethyl) amino N methylsulfonyl aniline, including:

[0063] During filtration, the filtration temperature was controlled at 25°C;

[0064] The vacuum degree during rotary evaporation is not less than 0.9MPa;

[0065] During vacuum distillation, the distillation temperature should be controlled not to exceed 60°C;

[0066] When the solvent recovery rate reaches more than 95%, the distillation is stopped.

[0067] In some embodiments, the alkylation reaction is carried out at a reaction pressure of 0.3-0.8 MPa and a reaction temperature of 90-100°C.

[0068] In some embodiments, the alkylation reaction is carried out at a reaction pressure of 0.75 MPa and a reaction temperature of 92.5 °C.

[0069] In some embodiments, the following steps are also included:

[0070] The target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline is distilled to obtain a product with a purity of more than 98%.

[0071] According to one embodiment, the target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline is distilled to obtain a product with a purity of more than 98%, comprising:

[0072] The preheating temperature before distillation is controlled at 50°C;

[0073] When the product purity test result reaches 98%, the distillation is stopped.

[0074] The present application further provides 3-(N,N-diethyl)amino-N-methylsulfonylaniline prepared by a method for synthesizing a disperse dye intermediate.

[0075] The present application further provides an application of a disperse dye intermediate synthesis method in dye production.

[0076] The filtrate after crystallization of the alkylation product of the disperse dye intermediate synthesis method of the embodiment of the present invention is an ammonium chloride solution, which is concentrated after decolorization to produce byproduct ammonium chloride, and the aqueous phase is condensed to apply this step; the stratified aqueous phase is ammonium sulfate and ammonium acetate solution, which is concentrated after decolorization to produce byproduct ammonium fertilizer, and the aqueous phase is condensed to apply this step. The salt crystals obtained in the final product synthesis step are sodium chloride and a small amount of unreacted sodium carbonate and sodium bicarbonate salt crystals, which are dissolved in water and neutralized with hydrochloric acid to produce a sodium chloride solution, which is concentrated after decolorization to produce byproduct sodium chloride, and the aqueous phase is condensed to apply this step. The solvent and raw materials are recovered by distillation and this step is applied. The invention has mild reaction conditions, low equipment requirements, and high process safety; high product conversion rate, low raw material cost; easy treatment of three wastes (byproduct industrial salt, water reuse), low environmental protection treatment costs, and low pollution. It has extremely high industrial value.

[0077] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for synthesizing a disperse dye intermediate, characterized in that: The steps include: The m-aminoacetanilide is subjected to an alkylation reaction with ethyl chloride, and ammonia water is used as an acid-binding agent to obtain 3-(N,N-diethylamino)acetanilide, which is cooled and crystallized and then filtered. The chemical equation is as follows: The obtained 3-(N,N-diethylamino)acetanilide is refluxed and hydrolyzed in 30-50% dilute sulfuric acid for 3-5 hours, and the hydrolyzate is neutralized with ammonia water at a temperature below 50°C. The aqueous phase is removed by layering to obtain an oil phase, i.e., 3-(N,N-diethylamino)aniline. The chemical equation is as follows: The obtained 3-(N,N-diethylamino)aniline was dissolved in methanol, sodium carbonate was added as an acid binding agent, and excess methylsulfonyl chloride was added dropwise at low temperature to react. The reaction system was a homogeneous solution, and the chemical equation was expressed as follows: After the reaction, the salt crystals are removed by filtration, and the solvent and raw materials are recovered by rotary evaporation and reduced pressure distillation to obtain the target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline.

2. The method for synthesizing a disperse dye intermediate according to claim 1, wherein The alkylation reaction is carried out at a reaction pressure of 0.3 to 0.8 MPa and a reaction temperature of 90 to 100°C.

3. The method for synthesizing a disperse dye intermediate according to claim 2, wherein The alkylation reaction was carried out at a reaction pressure of 0.75 MPa and a reaction temperature of 92.5°C.

4. The method for synthesizing a disperse dye intermediate according to claim 1, wherein The following steps are also included: The target product 3-(N,N-diethyl)amino-N-methylsulfonylaniline is distilled to obtain a product with a purity of more than 98%.

5. 3-(N,N-diethyl)amino-N-methylsulfonylaniline prepared by the method for synthesizing a disperse dye intermediate according to any one of claims 1 to 4.

6. Use of the method for synthesizing a disperse dye intermediate according to any one of claims 1 to 4 in dye production.

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