阅读说明：本技术 一种4,4’-双氯甲基联苯的生产工艺 (Production process of 4, 4' -dichloromethyl biphenyl ) 是由 马学文 葛德三 刘文平 张彦军 于 2020-11-20 设计创作，主要内容包括：本发明涉及一种4,4’-双氯甲基联苯的生产工艺,具体包括如下步骤：步骤一、反应：先向反应釜中加入溶剂,在搅拌条件下向反应釜内加入联苯,搅拌15～25min后,继续向反应釜中加入多聚甲醛、复合催化剂,然后控制物料为20～40℃,在搅拌的同时启动超声波,通入HCl气体,保证有尾气产生,搅拌反应5～8h,停止通气,反应结束,过滤,得BCMB溶液,备用；步骤二、水洗：首先向水洗釜中加入纯净水,然后将BCMB溶液加入水洗釜中,搅拌15～25min后,静置至分层,排出水相,回收溶剂,蒸馏结束后,将物料送至水洗结晶釜,于小于等于20℃低温结晶、离心,得BCMB粗品；本发明收率高,反应时间短。(The invention relates to a production process of 4, 4' -dichloromethyl biphenyl, which specifically comprises the following steps: step one, reaction: adding a solvent into a reaction kettle, adding biphenyl into the reaction kettle under a stirring condition, stirring for 15-25 min, then continuously adding polyformaldehyde and a composite catalyst into the reaction kettle, controlling the temperature of the materials to be 20-40 ℃, starting ultrasonic waves while stirring, introducing HCl gas, ensuring that tail gas is generated, stirring for reaction for 5-8 h, stopping introducing the gas, finishing the reaction, and filtering to obtain a BCMB solution for later use; step two, water washing: firstly, adding purified water into a washing kettle, then adding a BCMB solution into the washing kettle, stirring for 15-25 min, standing until layering, discharging a water phase, recovering a solvent, after distillation is finished, sending the material to a washing crystallization kettle, crystallizing at a low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product; the method has high yield and short reaction time.)

1. The production process of 4, 4' -dichloromethyl biphenyl is characterized by comprising the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl to paraformaldehyde to the composite catalyst to the solvent of 1: 0.5-1.5: 0.05-0.15: 3.0-3.5, adding a solvent into a reaction kettle, adding biphenyl into the reaction kettle under the stirring condition, stirring for 15-25 min, continuing to add polyformaldehyde and a composite catalyst into the reaction kettle, controlling the temperature of the materials to be 20-40 ℃, starting ultrasonic waves while stirring, introducing HCl gas to ensure that tail gas is generated, stirring for 5-8 h, stopping ventilation, finishing the reaction, and filtering to obtain a BCMB solution for later use; the composite catalyst is a mixture of a 4A molecular sieve and monochloroacetic acid in a mass ratio of 1: 2-5;

step two, water washing:

adding purified water into a washing kettle according to the mass ratio of the solvent to the purified water of 1: 1.0-1.5, adding the BCMB solution into the washing kettle, stirring for 15-25 min, standing until layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material to a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product.

2. The production process of 4, 4' -bischloromethylbiphenyl according to claim 1, further comprising the steps of: step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1: 4-6, firstly adding toluene into a refined water washing kettle, then adding a BCMB crude product, heating materials in the kettle to 100 ℃, detecting the pH value of the solution to be neutral after the BCMB is dissolved, and filtering insoluble impurities to obtain a toluene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product.

3. The process for producing 4, 4' -bischloromethylbiphenyl according to claim 2, wherein in step 3, when the pH of the test solution is not neutral, the test solution is washed with water at 100 ℃ until the pH is neutral, and then insoluble impurities are filtered off.

4. The production process of 4, 4' -bischloromethylbiphenyl according to claim 1, comprising the steps of: in the step one, cyclohexane is adopted as the solvent.

5. The production process of 4, 4' -bischloromethylbiphenyl according to claim 1, wherein the power of the ultrasonic wave is 800-1200W.

6. The production process of 4, 4' -bischloromethylbiphenyl according to claim 1, wherein the mass ratio of the 4A molecular sieve to monochloroacetic acid is 1: 3.5.

7. the production process of 4, 4' -bischloromethylbiphenyl according to claim 1, wherein the stirring speed is 15-35 rpm when the ultrasonic waves and the stirring are simultaneously applied.

Technical Field

The invention belongs to the field of preparation of 4,4 '-dichloromethyl biphenyl, and particularly relates to a production process of 4, 4' -dichloromethyl biphenyl.

Background

4,4 '-bischloromethylbiphenyl, BCMB for short, is the raw material of CBS series fluorescent whitening agent in stilbene biphenyl class high-efficient fluorescent whitening agent, 4' -di (chloromethyl) biphenyl mainly adopts biphenyl chloromethylation reaction to prepare at present at home and abroad industry, however, the main problem that this process exists is: the chloromethylation reaction of biphenyl is a heterogeneous reaction, and the synthesized 4, 4' -bischloromethylbiphenyl is easy to continue to react due to the existence of two relatively active chloromethyl groups, so that side reaction occurs, which causes the reaction conditions of the reaction to be extremely difficult to control, more side reactions, more product impurity types and low purity of crude products. The main by-products of this reaction are: monochloromethylated products, polychlorinated methylated products, chloromethylated products in different positions, further reaction coupling of the obtained products, chloromethylated products and the like of biphenyl, and the side reactions are not independently carried out, and are simultaneously or cross-reacted in most cases, such as: the obtained product is further reacted and coupled, and the chloromethylation product is further subjected to monochloro methylation or polychlorinated chloromethylation reaction. In order to reduce the production of by-products, the conventional method is to use zinc chloride with moderate activity as a catalyst and perform the chloromethylation reaction of biphenyl by using a low temperature of 20 ℃ or less and a prolonged reaction time, but even if the yield of 4,4 '-bischloromethylbiphenyl is only 60%, and the use amount of the zinc chloride as a catalyst is large, the washing frequency is increased, so that the synthesis process of 4, 4' -bischloromethylbiphenyl needs to be improved to shorten the synthesis process time, reduce the cost and improve the reaction yield.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a production process of 4, 4' -dichloromethyl biphenyl.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a production process of 4, 4' -dichloromethyl biphenyl specifically comprises the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl to paraformaldehyde to the composite catalyst to the solvent of 1: 0.5-1.5: 0.05-0.15: 3.0-3.5, adding a solvent into a reaction kettle, adding biphenyl into the reaction kettle under the stirring condition, stirring for 15-25 min, continuing to add polyformaldehyde and a composite catalyst into the reaction kettle, controlling the temperature of the materials to be 20-40 ℃, starting ultrasonic waves while stirring, introducing HCl gas to ensure that tail gas is generated, stirring for 5-8 h, stopping ventilation, finishing the reaction, and filtering to obtain a BCMB solution for later use; the composite catalyst is a mixture of a 4A molecular sieve and monochloroacetic acid in a mass ratio of 1: 2-5;

step two, water washing:

adding purified water into a washing kettle according to the mass ratio of a solvent to the purified water of 1: 1.0-1.5, adding a BCMB solution into the washing kettle, stirring for 15-25 min, standing until layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material to a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product;

further, the production process of the 4, 4' -bischloromethylbiphenyl also comprises the following steps: step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1: 4-6, firstly adding toluene into a refined water washing kettle, then adding a BCMB crude product, heating materials in the kettle to 100 ℃, detecting the pH value of the solution to be neutral after the BCMB is dissolved, and filtering insoluble impurities to obtain a toluene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product.

Further, when the pH value of the detection solution is not neutral in the third step, the detection solution is washed to be neutral by water with the temperature of 100 ℃, and then insoluble impurities are filtered.

Further, cyclohexane is used as the solvent in the first step.

Furthermore, the power of the ultrasonic wave is 800-1200W.

Further, the mass ratio of the 4A molecular sieve to the monochloroacetic acid is 1: 3.5.

further, the stirring speed is 15-35 r/min when the ultrasonic waves and the stirring are simultaneously applied.

The reaction equation of the invention:

4,4 '-dichloromethyl biphenyl is used as a raw material for synthesizing CBS series fluorescent whitening agents, the preparation method thereof generally has the problems of long reaction time, low yield and high post-treatment difficulty, and how to find the preparation method of the 4, 4' -dichloromethyl biphenyl with simple process, short reaction time and high yield is a hotspot researched by the industry, under the trend of the purpose, the inventor considers the limitation of simple stirring on local dispersion, tries to adopt an ultrasonic mode or a mode of combining mechanical stirring and ultrasonic wave to replace the traditional mechanical stirring mode, and uses CuCl₂、AlCl₃、CoCl₂Formic acid, monochloroacetic acid and phosphoric acid, which catalyze the reaction, unfortunately fail to achieve satisfactory results, and when the inventors intend to give up, it was unexpectedly found that the addition of a 4A molecular sieve in an appropriate ratio is advantageous for the reaction, and therefore, the inventors have conducted intensive studies on the selection of the molecular sieve and the catalyst, and have completed the present invention.

In the search, the inventors found that: when the 4A molecular sieve and monochloroacetic acid are added in the reaction at the same time, the use amount of the catalyst can be obviously reduced, however, when the inventor is happy to find out that whether mechanical stirring and ultrasonic waves are used together, the dependence of the use power of the ultrasonic waves on the reduction of the reaction temperature and the reduction of the reaction time are critically influenced, the ratio of the 4A molecular sieve and the monochloroacetic acid is adjusted, the treatment mode of combining mechanical stirring and ultrasonic waves is adopted, and the stirring speed and the power of the ultrasonic waves are adjusted, so that the use amount of the catalyst can be obviously reduced, the reaction rate is improved, the reaction time is shortened, the range of the reaction temperature is expanded, the sensitivity of the reaction to the temperature is reduced, the aim of the invention cannot be achieved by simply adjusting any one of the two, the mass ratio of the 4A molecular sieve to the monochloroacetic acid is finally determined to be 1:3.5 through exploration and verification, the treatment mode of combining mechanical stirring and ultrasonic waves, wherein the power of the ultrasonic waves is more than or equal to 800W, and the stirring rotating speed is preferably 25 r/min.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a novel production process of 4,4 '-dichloromethyl biphenyl for the first time, and provides a new idea for producing 4, 4' -dichloromethyl biphenyl in the industry.

The synthesis method of 4, 4' -dichloromethyl biphenyl provided by the invention has the advantages of low cost, high yield, low reaction temperature sensitivity and simple post-treatment process,

the synthesis method of 4, 4' -dichloromethyl biphenyl provided by the invention has the advantages that the catalyst consumption is low, the difficulty of the post-treatment process is reduced, and the used catalyst 4A molecular sieve can be reused, activated and regenerated.

The yield of the 4,4 ' -bischloromethylbiphenyl obtained by the method for synthesizing the 4,4 ' -bischloromethylbiphenyl provided by the invention is 87%, and the purity of the refined 4,4 ' -bischloromethylbiphenyl product is 98%.

Detailed Description

The production process of the present invention is specifically exemplified below.

The biphenyl of the invention is purchased from Shanghai crystal Shanghai chemical industry Co., Ltd, and has the purity of 99 percent;

paraformaldehyde was purchased from Hebei aerospace chemical Co., Ltd.

Example 1

A production process of 4, 4' -dichloromethyl biphenyl specifically comprises the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl, paraformaldehyde, a composite catalyst and a solvent cyclohexane of 1:0.8: 0.10: 3.25, adding 1300Kg of cyclohexane solvent into the reaction kettle, adding 400Kg of biphenyl into the reaction kettle under the stirring condition of 50 r/min, stirring for 20min, and then continuously adding 320Kg of paraformaldehyde and 40Kg of composite catalyst (the mass ratio of the mixture of the 4A molecular sieve and monochloroacetic acid is 1:3.5, namely 8.9Kg of the 4A molecular sieve and 31.1Kg of monochloroethane) into the reaction kettle; then, controlling the material to be 20-40 ℃ (the temperature is changed in the reaction process, and only the temperature is controlled to be 20-40 ℃), simultaneously starting ultrasonic waves under the stirring condition of 25 revolutions per minute, leading HCl gas into the ultrasonic waves with the power of 1000W to ensure that tail gas is generated, stirring and reacting for 6.5 hours, stopping ventilation, finishing the reaction, and filtering to obtain BCMB solution for later use; sampling, detecting the content of BCMB in the BCMB solution, and calculating to obtain 577Kg of total BCMB in the BCMB solution, wherein the reaction yield is 88.8%;

step two, water washing:

adding 1500Kg of purified water into a washing kettle according to the mass ratio of the solvent to the purified water of 1:1.15, then adding the BCMB solution into the washing kettle, stirring for 20min, standing until layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material to a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product;

step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1: adding 2885Kg of toluene into a refined water washing kettle, adding a BCMB crude product, heating materials in the kettle to 100 ℃, detecting that the pH of the solution is neutral (if the pH is not neutral, the solution needs to be washed to be neutral by water at 100 ℃) after the BCMB is dissolved, and filtering insoluble impurities to obtain a toluene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product. The purity of the finished BCMB product is detected to be 99.7 percent.

Example 2

A production process of 4, 4' -dichloromethyl biphenyl specifically comprises the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl to paraformaldehyde to a composite catalyst to a solvent cyclohexane of 1:1.2: 0.13: 3.0, firstly adding 1200Kg of cyclohexane solvent into a reaction kettle, adding 400Kg of biphenyl into the reaction kettle under the stirring condition of 60 revolutions per minute, stirring for 25 minutes, then continuously adding 480Kg of paraformaldehyde and 52Kg of composite catalyst (the mass ratio of 4A molecular sieve to monochloroacetic acid is 1:4.5, namely 9.5Kg of 4A molecular sieve and 42.5Kg of monochloroacetic chloride) into the reaction kettle, then controlling the materials to be 20-40 ℃ (the temperature is changed in the reaction process, as long as the temperature is controlled to be 20-40 ℃), simultaneously starting ultrasonic waves under the stirring condition of 20 revolutions per minute, wherein the power of the ultrasonic waves is 1200W, introducing HCl gas to ensure that tail gas is generated, stirring for 5 hours, stopping ventilation, finishing the reaction, and filtering to obtain a BCMB solution for later use; sampling, detecting the content of BCMB in the BCMB solution, and calculating to obtain the total amount of the BCMB in the BCMB solution to be 570Kg, wherein the reaction yield is 87.7%;

step two, water washing:

adding 1560Kg of purified water into a washing kettle according to the mass ratio of the solvent to the purified water of 1:1.3, then adding the BCMB solution into the washing kettle, stirring for 25min, standing for layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material to a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product;

step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1: 5.5, firstly adding 3135Kg of toluene into a refined water washing kettle, then adding a BCMB crude product, heating the materials in the kettle to 100 ℃, detecting the pH value of the solution to be neutral (if the pH value is not neutral, washing the solution to be neutral by using water at 100 ℃) after the BCMB is dissolved, and filtering insoluble impurities to obtain a toluene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product. The purity of the finished BCMB product is detected to be 99.4%.

Example 3

A production process of 4, 4' -dichloromethyl biphenyl specifically comprises the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl, paraformaldehyde, a composite catalyst and a solvent cyclohexane of 1:0.7: 0.08: 3.5, adding 1400Kg of cyclohexane solvent into a reaction kettle, adding 400Kg of biphenyl into the reaction kettle under the stirring condition of 50 revolutions per minute, stirring for 20 minutes, continuously adding 280Kg of paraformaldehyde and 32Kg of composite catalyst (the mass ratio of the 4A molecular sieve to monochloroacetic acid is 1:2.5, namely 9.1Kg of the 4A molecular sieve and 22.9Kg of monochloroacetic chloride) into the reaction kettle, then controlling the materials to be 20-40 ℃ (the temperature is changed in the reaction process, as long as the temperature is controlled to be 20-40 ℃), simultaneously starting ultrasonic waves under the stirring condition of 30 revolutions per minute, wherein the power of the ultrasonic waves is 800W, introducing HCl gas to ensure that tail gas is generated, stirring and reacting for 8 hours, stopping ventilation, finishing the reaction, and filtering to obtain a BCMB solution for later use; the composite catalyst is a mixture of a 4A molecular sieve and monochloroacetic acid in a mass ratio of 1: 2.5; sampling, detecting the content of BCMB in the BCMB solution, and calculating to obtain the total amount of the BCMB in the BCMB solution to be 562Kg and the reaction yield to be 86.5%;

step two, water washing:

according to the mass ratio of the solvent to the purified water of 1:1.0, firstly adding 1400Kg of purified water into a washing kettle, then adding the BCMB solution into the washing kettle, stirring for 20min, standing until layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material into a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product;

step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1:4.5, firstly adding 2529Kg of methylbenzene into a refined water washing kettle, then adding a BCMB crude product, heating materials in the kettle to 100 ℃, detecting the pH value of the solution to be neutral (if the pH value is not neutral, washing the solution to be neutral by using water at 100 ℃) after the BCMB is dissolved, and filtering insoluble impurities to obtain a methylbenzene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product. The purity of the finished BCMB product is detected to be 99.5 percent.

Comparative example 1

The same as example 1, except that in the first step, the mass of the 4A molecular sieve added was 15.2Kg (the amount of the composite catalyst added was 46.3, the mass ratio of the 4A molecular sieve to monochloroacetic acid was 1:2, and the mass ratio of biphenyl to the composite catalyst was 0.12), and the yield was 0.

Comparative example 2

The same as example 1, except that in the first step, 4.5Kg of 4A molecular sieve was added (35.6 for the amount of the composite catalyst, 1:6.9 for the mass ratio of 4A molecular sieve to monochloroacetic acid, and 0.09 for the mass ratio of biphenyl to composite catalyst), and the yield was 0.

Comparative example 3

The same as example 1, except that in the first step, 50.2Kg of monochloroethane was added (the amount of the composite catalyst added was 59.1, the mass ratio of 4A molecular sieve to monochloroacetic acid was 1:5.6, and the mass ratio of biphenyl to the composite catalyst was 0.15), and the yield was 0.

Comparative example 4

The same as example 1, except that in the first step, the mass of the monochloroethane added was 18.5Kg (the amount of the composite catalyst added was 27.4, the mass ratio of the 4A molecular sieve to the monochloroacetic acid was 1:2.1, and the mass ratio of the biphenyl to the composite catalyst was 0.07), and the yield was 0.

Comparative example 5

The same as example 1, except that in the first step, only mechanical stirring was used, no ultrasonic wave was applied, the reaction time was 12 hours, and the yield was 11%.

Comparative example 6

The same as example 1, except that in the first step, only ultrasonic waves were used without mechanical stirring, the power of the ultrasonic waves was 1000W, the reaction time was 15 hours, and the yield was 8%.

Comparative example 7

The same as example 1, except that in the first step, the power of ultrasonic wave was 400W, the reaction time was 10 hours, and the yield was 40%.

Comparative example 8

The same as example 1, except that in the first step, the power of ultrasonic wave was 1700W, the reaction time was 4 hours, and the yield was 49%.

Comparative example 9

The same as example 1, except that in the first step, when ultrasonic wave was applied simultaneously with stirring, the rotation speed of stirring was 40 rpm, the reaction time was 5 hours, and the yield was 60%.

Comparative example 10

The same as example 1, except that in the first step, when ultrasonic wave was applied simultaneously with stirring, the rotation speed of stirring was 10 rpm, the reaction time was 9 hours, and the yield was 20%.

Comparative example 11: conventional zinc chloride catalytic process

A production process of 4, 4' -dichloromethyl biphenyl specifically comprises the following steps:

step one, reaction: under the action of the composite catalyst, reacting biphenyl, paraformaldehyde and hydrogen chloride to generate BCMB (4, 4' -bischloromethylbiphenyl);

according to the mass ratio of biphenyl, paraformaldehyde, a composite catalyst and a solvent cyclohexane of 1:0.8: 0.90: 3.25, adding 1300Kg of cyclohexane solvent into the reaction kettle, adding 400Kg of biphenyl into the reaction kettle under the stirring condition of 50 revolutions per minute, stirring for 20 minutes, and continuously adding 320Kg of paraformaldehyde and 360Kg of zinc chloride catalyst into the reaction kettle; then controlling the temperature of the material to be 18-22 ℃, introducing HCl gas to ensure that tail gas is generated, stirring for reacting for 25 hours, stopping introducing the gas, finishing the reaction, and filtering to obtain BCMB solution for later use; sampling, detecting the content of BCMB in the BCMB solution, and calculating to obtain 392Kg of total BCMB in the BCMB solution, wherein the reaction yield is 60.2%;

step two, water washing:

adding 1500Kg of purified water into a washing kettle according to the mass ratio of the solvent to the purified water of 1:1.15, then adding the BCMB solution into the washing kettle, stirring for 20min, standing until layering, discharging a water phase, pumping an organic phase into a distillation kettle, distilling at normal pressure to 100 ℃, distilling at negative pressure for 10min, recovering the solvent, after the distillation is finished, sending the material to a washing crystallization kettle, crystallizing at the low temperature of less than or equal to 20 ℃, and centrifuging to obtain a BCMB crude product;

step three, refining and drying:

according to the mass ratio of BCMB to toluene of 1: adding 1960Kg of toluene into a refined water washing kettle, adding a crude product of BCMB, heating the materials in the kettle to 100 ℃, detecting the pH value of the solution to be neutral (if the pH value is not neutral, washing the solution to be neutral by water at 100 ℃) after the BCMB is dissolved, and filtering insoluble impurities to obtain a toluene solution of the BCMB; and then, cooling the toluene solution of the BCMB to 40-60 ℃, then sending the solution to a refining crystallization kettle, carrying out low-temperature crystallization at the temperature of less than or equal to 10 ℃, centrifuging, and drying a filter cake to obtain the BCMB finished product. The purity of the BCMB finished product is detected to be 99.1 percent.

The embodiments described above are only preferred embodiments of the invention and are not exhaustive of the possible implementations of the invention. Any obvious modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the spirit and scope of the present invention.