Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a synthesis method of high-quality m-phenylenediamine, and the product obtained by the method has high purity, high yield, simple post-treatment and low cost.
The invention relates to a synthesis method of high-quality m-phenylenediamine, which comprises the following steps:
(1) dissolving isophthalonitrile in dimethyl sulfoxide, adding anhydrous sodium carbonate and hydrogen peroxide, then adding a catalyst, reacting at 60-80 ℃, and filtering and washing to obtain isophthalimide after the reaction is finished;
(2) under the protection of nitrogen, dissolving sodium hypochlorite in water, controlling the temperature to be-5-20 ℃, adding the isophthalimide under rapid stirring, after the addition, carrying out heat preservation reaction for 2 hours, and then heating to 40-50 ℃ for reaction for 2-3 hours;
(3) and after the reaction is finished, adjusting the pH value of the reaction solution to 7.5-8.5, adding an antioxidant into the reaction solution, distilling under reduced pressure, extracting, and concentrating to obtain the m-phenylenediamine.
In the step (1), the addition amount of dimethyl sulfoxide is 10-15 times of the mass of isophthalonitrile, and the mass of anhydrous sodium carbonate is 5-10% of the mass of isophthalonitrile.
In the step (1), the catalyst is MnO2/SiO2Or Au/TiO2Or Raney-Cu, the adding amount of the catalyst is 0.5 to 2.0 percent of the mol amount of the isophthalonitrile.
In the step (1), the mass fraction of the hydrogen peroxide is 32%, and the molar ratio of the pure substances is as follows: h2O2=1:1.2~1.3。
In the step (2), the mass of the water is 4.5-8.0 times of that of the sodium hypochlorite.
In step (2), the molar ratio of isophthalimide: sodium hypochlorite 1: 2.2-2.5.
In the step (3), the antioxidant is selected from hindered phenol antioxidants BBMBP or Cyanox2246 or BHT; antioxidant, in terms of mole ratios: isophthalimide is 0.5-1: 1.
In the step (3), after reduced pressure distillation, extracting the kettle substrate by using an organic solvent, wherein the amount of the organic solvent is 3-7 times of the weight of the isophthalimide, and equally dividing into three times of extraction. The organic solvent is selected from ethanol or dimethyl sulfoxide or acetone.
Compared with the prior art, the invention has the beneficial effects that: the synthesis process is simple, the post-treatment is simple, the problems of easy oxidation and low quality of the m-phenylenediamine are effectively solved, the yield reaches more than 95 percent, the purity reaches more than 99 percent, the production cost is greatly reduced, and the market demand on high-quality resorcinol is met.
Detailed Description
In order to better understand the technical scheme of the present invention, the following detailed description of the present invention is provided by way of examples, but the present invention should not be construed as limited to the above description.
The percentages mentioned in the following examples are given by mass.
Example 1
128g of isophthalonitrile is dissolved in 1280g of dimethyl sulfoxide, 12.8g of anhydrous sodium carbonate and 127.2g of 32% hydrogen peroxide are added into the reaction solution at a time, and then Au/TiO is added2,Au/TiO2The addition amount of the isophthalonitrile is 0.5 percent of the molar amount of the isophthalonitrile, the temperature is reduced after the catalytic hydrolysis reaction is carried out for 4 hours at the temperature of 80 ℃, and the reaction solution is filtered and washed to obtain 160.8g of pure product of the isophthalimide.
Under the protection of nitrogen, firstly, 160.4g of sodium hypochlorite is dissolved in 800g of water, 160.8g of isophthalimide is added under the condition of rapid stirring, the feeding temperature is controlled to be-5 ℃, the reaction is carried out for 2 hours under the heat preservation condition after the addition is finished, and then the temperature is raised to 50 ℃ for reaction for 2 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for adjusting the pH value of reaction liquid to be 7.5, meanwhile, 0.9mol of antioxidant BHT is added, the water is removed by reduced pressure distillation, 500g of ethanol is used for extraction in three batches at the bottom of a kettle, the ethanol extraction liquid is concentrated to obtain 104.8g of offwhite product m-phenylenediamine, the yield is 97.0 percent based on isophthalonitrile, and the purity of the product m-phenylenediamine is 99.8 percent through gas chromatography detection.
Example 2
128g of isophthalonitrile is dissolved in 1280g of dimethyl sulfoxide, 12.8g of anhydrous sodium carbonate and 137.8g of 32% hydrogen peroxide are added to the reaction solution at a time, and MnO is added2/SiO2,MnO2/SiO2The addition amount of the compound is 0.5 percent of the molar amount of the isophthalonitrile, the temperature is reduced after the catalytic hydrolysis reaction is carried out for 5 hours at the temperature of 80 ℃, and the reaction solution is filtered and washed to obtain 158.8g of pure product of the isophthalimide.
Under the protection of nitrogen, firstly, 180g of sodium hypochlorite is dissolved in 1400g of water, 158.8g of isophthalimide is added under the condition of rapid stirring, the feeding temperature is controlled to be 20 ℃, the reaction is carried out for 2 hours after the feeding is finished, and then the temperature is raised to 50 ℃ for reaction for 3 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for adjusting the pH value of reaction liquid to be 8.5, meanwhile, 0.5mol of antioxidant BHT is added, the water is removed by reduced pressure distillation, 1000g of ethanol is used for extraction in three batches at the bottom of a kettle, ethanol extract is concentrated to obtain 103.1g of off-white product m-phenylenediamine, the yield is 95.5 percent based on isophthalonitrile, and the purity of the product m-phenylenediamine is 99.7 percent detected by gas chromatography.
Example 3
128g of isophthalonitrile was dissolved in 1920g of dimethyl sulfoxide, and 6.4g of anhydrous sodium carbonate and 128.4g of 32% hydrogen peroxide were added to the reaction solution at a time, followed by addition of MnO2/SiO2,MnO2/SiO2The addition amount of the compound is 2.0 percent of the molar amount of the isophthalonitrile, the temperature is reduced after 5 hours of catalytic hydrolysis reaction at 60 ℃, and the reaction solution is filtered and washed to obtain 159.8g of pure product of the isophthalimide.
Under the protection of nitrogen, firstly, 166.7g of sodium hypochlorite is dissolved in 1000g of water, 159.8g of the intermediate isophthalimide is added under the rapid stirring, the feeding temperature is controlled to be minus 5 ℃, the reaction is carried out for 2 hours under the heat preservation after the addition is finished, and then the temperature is raised to 50 ℃ for reaction for 2 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for regulating the pH value of reaction liquid to be 7.5, cyanox22460.6mol is added at the same time, reduced pressure distillation is carried out to remove water, 800g of ethanol is used for extraction at the bottom of a kettle in three batches, ethanol extract is concentrated to obtain an off-white product, namely m-phenylenediamine 103.8g, the yield is 96.1 percent based on the content of the isophthalonitrile, and the purity of the m-phenylenediamine is 99.5 percent through gas chromatography detection.
Example 4
128g of isophthalonitrile is dissolved in 1520g of dimethyl sulfoxide, 9g of anhydrous sodium carbonate and 130.6g of 32% hydrogen peroxide are added into the reaction solution at one time, then Raney-Cu is added, the addition amount of the Raney-Cu is 2.0% of the molar amount of the isophthalonitrile, the temperature is reduced after the catalytic hydrolysis reaction is carried out for 3h at the temperature of 60 ℃, and 161.8g of pure isophthalimide is obtained after the reaction solution is filtered and washed with water.
Under the protection of nitrogen, firstly, 161.4g of sodium hypochlorite is dissolved in 1130g of water, 161.8g of the intermediate isophthalimide is added under the condition of rapid stirring, the feeding temperature is controlled to be 10 ℃, the reaction is carried out for 2 hours under the heat preservation condition after the addition is finished, and then the temperature is raised to 40 ℃ for reaction for 3 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for regulating the pH value of reaction liquid to be 8.0, 0.9mol of antioxidant BBMBP is added at the same time, the water is removed by reduced pressure distillation, 900g of ethanol is used for extraction in three batches at the bottom of a kettle, the ethanol extraction liquid is concentrated to obtain an off-white product m-phenylenediamine of 104.4g, the yield is 96.7 percent based on the content of isophthalonitrile, and the purity of the m-phenylenediamine product is 99.3 percent by gas chromatography detection.
Example 5
128g of isophthalonitrile is dissolved in 1660g of dimethyl sulfoxide, 10.2g of anhydrous sodium carbonate and 133.6g of 32% hydrogen peroxide are added to the reaction solution at a time, and then Au/TiO is added2,Au/TiO2The addition amount of the compound is 2.0 percent of the molar amount of the isophthalonitrile, the temperature is reduced after the catalytic hydrolysis reaction is carried out for 3.5h at the temperature of 65 ℃, and the reaction solution is filtered and washed to obtain 161.2g of pure isophthalimide.
Under the protection of nitrogen, firstly 182.7g of sodium hypochlorite is dissolved in 1000g of water, 161.2g of the intermediate isophthalimide is added under the condition of rapid stirring, the feeding temperature is controlled at 10 ℃, the reaction is carried out for 2 hours under the heat preservation condition after the addition is finished, and then the temperature is raised to 40 ℃ for reaction for 2 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for regulating the pH value of reaction liquid to be 7.5, 0.6mol of antioxidant BBMBP is added at the same time, the water is removed by reduced pressure distillation, 900g of dimethyl sulfoxide is used for extraction in three batches at the bottom of a kettle, the extraction liquid of the dimethyl sulfoxide is concentrated to obtain 103.8g of off-white product m-phenylenediamine, the yield is 96.1 percent based on the isophthalonitrile, and the purity of the product m-phenylenediamine is 99.6 percent detected by gas chromatography.
Example 6
128g of isophthalonitrile is dissolved in 1600g of dimethyl sulfoxide, 9g of anhydrous sodium carbonate and 130.6g of 32% hydrogen peroxide are added into the reaction solution at one time, then Raney-Cu is added, the addition amount of the Raney-Cu is 1.0% of the molar amount of the isophthalonitrile, the temperature is reduced after the catalytic hydrolysis reaction is carried out for 3h at the temperature of 60 ℃, and the reaction solution is filtered and washed by water to obtain 160.0g of pure isophthalimide.
Under the protection of nitrogen, firstly 181.4g of sodium hypochlorite is dissolved in 1000g of water, 160.0g of the intermediate isophthalimide is added under the condition of rapid stirring, the feeding temperature is controlled to be 5 ℃, the reaction is carried out for 2 hours under the heat preservation after the addition is finished, and then the temperature is raised to 40 ℃ for reaction for 3 hours;
after the reaction is finished, the temperature is reduced to normal temperature, hydrochloric acid is used for adjusting the pH value of reaction liquid to be 8.5, antioxidant Cyanox22460.9mol is added at the same time, the reduced pressure distillation is carried out to remove the water, 1000g of acetone is used for extraction in three batches at the bottom of a kettle, the acetone extraction liquid is concentrated to obtain an off-white product, namely m-phenylenediamine 104.2g, the yield is 96.5 percent based on the content of the isophthalonitrile, and the purity of the m-phenylenediamine is 99.4 percent through gas chromatography detection.