Preparation method of BVPE

Abstract

The invention discloses a preparation method of BVPE, and the preparation method comprises the following steps: dehydrating 4, 4 '-(1, 2-ethanedialkyl) bis (alpha-methylbenzyl alcohol) in the presence of a catalytic material to generate BVPE; the catalytic materials include a pyridine-based catalyst, a p-toluenesulfonic acid-based catalyst, and a chlorobenzene-based catalyst. According to the preparation method provided by the invention, the acidic environment of a reaction system is changed by introducing pyridine, the polymerization phenomenon of olefin is effectively reduced, and the yield and purity of BVPE are improved. Besides, the raw materials are relatively easy to obtain, and the production cost is greatly reduced, so that the industrial application potential of the method is further enhanced, and large-scale production of BVPE becomes possible.

Description

Technical Field

[0001] The invention relates to the field of organic synthesis, and in particular to a method for preparing BVPE. Background Art

[0002] BVPE (P,P'-divinyl-1,2-diphenylethane) is a widely used olefin monomer, and its annual demand both at home and abroad is also increasing rapidly.

[0003] At present, there are two main synthetic routes for the synthesis of BVPE.

[0004] Route 1 is to generate the target product BVPE by a genomic coupling reaction between p-chloromethylstyrene and magnesium powder under specific conditions. The advantage of this method is that the reaction is fast and a large amount of BVPE can be synthesized in a short time. At the same time, the occurrence of polymerization reaction is relatively small, which helps to maintain the purity of the product and high yield. The disadvantage is that p-chloromethylstyrene is expensive, which increases the production cost and has no advantages in industrial production.

[0005] Route 2, through the dehydration reaction of 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) under the action of an acidic catalyst, BVPE is produced. Although the raw material cost of this route is relatively low, since the dehydration reaction is carried out under acidic catalysis, the polymerization is very serious and the yield is generally low, which is difficult to meet the needs of large-scale production. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the current BVPE synthesis, the present invention provides a method for preparing BVPE, by introducing pyridine, changing the acidic environment of the reaction system, and dehydrating and synthesizing BVPE. 。 Optimized by experiments ， Effectively reduces the polymerization of olefins, Achieved High yield of BVPE synthesis The raw materials of this method are easily available, the cost is controllable, and it is suitable for industrial production.

[0007] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0008] A method for preparing BVPE comprises dehydrating 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) to generate BVPE in the presence of reaction materials; the reaction materials comprise a pyridine-based catalyst, a p-toluenesulfonic acid-based catalyst and a chlorobenzene-based solvent.

[0009] Preferably, the pyridine-based catalyst includes pyridine, collidine and tetramethylpyridine; and the chlorobenzene-based solvent includes chlorobenzene, xylene and trimethylbenzene.

[0010] Preferably, 30-60 times the weight of chlorobenzene relative to toluenesulfonic acid and 0.424-0.623 times the weight of pyridine relative to p-toluenesulfonic acid are used, preferably 1 part by weight of p-toluenesulfonic acid, 40 parts by weight of chlorobenzene and 0.5 parts by weight of pyridine are used.

[0011] Preferably, the preparation method comprises mixing p-toluenesulfonic acid, chlorobenzene and pyridine to prepare a mixed catalyst, adding 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol), and performing a dehydration reaction to obtain BVPE.

[0012] In this application, 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) is removed from chlorobenzene by removing two molecules of water under the catalysis of p-toluenesulfonic acid to generate BVPE. Since BVPE has two olefin structures, it is very easy to undergo polymerization under acidic conditions to generate various polymers, and it is difficult to obtain pure BVPE. By adding pyridine, a weak alkaline environment is provided in the solvent, which greatly reduces the repolymerization of BVPE and obtains BVPE with a high yield.

[0013] Preferably, the mixed catalyst prepared by mixing p-toluenesulfonic acid, chlorobenzene and pyridine includes: mixing p-toluenesulfonic acid, chlorobenzene and pyridine and then heating to prepare the mixed catalyst, the heating temperature is 35-45°C; at this temperature, it can fully reflux, promote the smooth start and progress of the hydrolysis reaction, avoid the increase of time loss caused by too low heating rate, and the increase of side reactions caused by too fast heating rate. The dehydration reaction to obtain BVPE includes: heating reflux reaction after adding 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol), the reaction time is 2.5-3.5 hours, separating the liquid, and vacuum distilling the upper layer to obtain BVPE.

[0014] Preferably, the heating reflux reaction comprises the following steps: heating the mixed catalyst to which 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) has been added for reflux reaction, separating the generated water, detecting the raw material content to a preset value, cooling and adding water, stirring and then standing.

[0015] Preferably, the temperature of the heating reflux reaction is 130-135° C.; and the detection of the raw material content to a preset value is that the detection raw material content is less than 1%.

[0016] Preferably, the vacuum distillation comprises the following steps: decompressing the mixed catalyst to which 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) has been added to recover chlorobenzene, cooling and adding methanol, stirring and centrifuging to separate solids, and drying the solids.

[0017] Preferably, the conditions for the reduced pressure recovery of chlorobenzene are to collect a fraction of 78-92°C at a pressure of 5.4-6.0 kPa; the temperature for adding methanol by cooling is 28-32°C, the stirring time is 50-70 min, and the centrifugation temperature is 13-17°C.

[0018] On the other hand, a synthesis method for preparing BVPE using 1,2-diphenylethane as a raw material comprises the following steps:

[0019] S1, using 1,2-diphenylethane as a raw material, reacting in a solvent under the action of aluminum chloride and acetyl chloride to obtain 4,4'-diacetyl diaryl ethane;

[0020] S2, under the action of sodium borohydride, 4,4'-diacetyl diaryl ethane reacts in a solvent to obtain 4,4'-(1,2-ethanedialkyl)bis(α-methylbenzyl alcohol);

[0021] S3, p-toluenesulfonic acid, chlorobenzene and pyridine are mixed evenly and heated, 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) is added to obtain a raw material mixture, and the mixture is heated under reflux for reaction for 2.5-3.5 hours, the liquids are separated, and the upper layer is vacuum distilled to obtain BVPE.

[0022] Advantages of the present invention: by introducing pyridine to change the acidic environment of the reaction system, the polymerization of olefins is effectively reduced, and the yield and purity of BVPE are improved. In addition, the raw materials of the present application are relatively easy to obtain and the production cost is greatly reduced, which further enhances the industrial application potential of the method and makes large-scale production of BVPE possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is the BVPE prepared in the embodiment of the present invention 1 H-NMR spectrum. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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. The test methods in the following embodiments that do not specify specific conditions are usually carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0026] Material Source

[0027] p-Toluenesulfonic acid, available from Jinan Renyuan Chemical Co., Ltd.;

[0028] Chlorobenzene, available from Jiangsu Longchang Chemical Co., Ltd.;

[0029] Pyridine, available from Shandong Kunda Biotechnology Co., Ltd.;

[0030] 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was purchased from Xi'an Tuochao Biotechnology Co., Ltd.

[0031] Example 1

[0032] The following preparation method according to the present application is used to prepare BVPE:

[0033] 15 kg of p-toluenesulfonic acid, 600 kg of chlorobenzene and 7.5 kg of pyridine were mixed evenly and heated to 40 degrees, stirred for 30 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the reaction was refluxed for 3 hours. The generated water was separated during the reaction. The raw material was detected to be less than 1%. The temperature was lowered to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The organic phase was washed with water again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the temperature was lowered to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 70 kg of product (purity 99.68%; yield 80.8%).

[0034] Example 2

[0035] The following preparation method according to the present application is used to prepare BVPE:

[0036] 15 kg of p-toluenesulfonic acid, 600 kg of chlorobenzene and 7.5 kg of pyridine were mixed evenly and heated to 38 degrees, stirred for 28 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the reaction was refluxed for 3 hours. The generated water was separated during the reaction. The raw material was detected to be less than 1%. The temperature was lowered to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The organic phase was washed with water again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the temperature was lowered to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 69.3 kg of product (purity 99.66; yield 80%).

[0037] Example 3

[0038] The following preparation method according to the present application is used to prepare BVPE:

[0039] 15 kg of p-toluenesulfonic acid, 600 kg of chlorobenzene and 7.5 kg of pyridine were mixed evenly and heated to 40 degrees, stirred for 30 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the reaction was refluxed for 2.5 hours. The generated water was separated during the reaction. The raw material was detected to be less than 1%. The temperature was lowered to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The organic phase was washed with water again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the temperature was lowered to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 66.9 kg of product (purity 99.48; yield 77.2%).

[0040] Example 4

[0041] The following preparation method according to the present application is used to prepare BVPE:

[0042] 15 kg of p-toluenesulfonic acid, 600 kg of chlorobenzene and 7.5 kg of pyridine were mixed evenly and heated to 40 degrees, stirred for 30 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the mixture was heated to reflux for 3 hours. The generated water was separated during the reaction, and the raw material was detected to be less than 2%. The mixture was cooled to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The mixture was washed with water once again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the mixture was cooled to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 68.5 kg of product (purity 99.55; yield 79.1%).

[0043] Example 5

[0044] The following preparation method according to the present application is used to prepare BVPE:

[0045] 15 kg of p-toluenesulfonic acid, 450 kg of chlorobenzene and 6.36 kg of pyridine were mixed evenly and heated to 40 degrees, stirred for 30 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the mixture was heated to reflux for 3 hours. The generated water was separated during the reaction, and the raw material was detected to be less than 2%. The mixture was cooled to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The mixture was washed with water once again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the mixture was cooled to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 60.8 kg of product (purity 99.3%; yield 70.2%).

[0046] Example 6

[0047] The following preparation method according to the present application is used to prepare BVPE:

[0048] 15 kg of p-toluenesulfonic acid, 900 kg of chlorobenzene and 0.623 kg of pyridine were mixed evenly and heated to 40 degrees, stirred for 30 minutes, 100 kg of 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) was added, and the mixture was heated to reflux for 3 hours. The generated water was separated during the reaction, and the raw material was detected to be less than 2%. The mixture was cooled to 20 degrees, 200 kg of water was added, stirred for 30 minutes, and the organic phase was separated by standing. The mixture was washed with water once again, and the pressure was reduced to below 80 degrees to recover most of the chlorobenzene. After the chlorobenzene was recovered, the mixture was cooled to 30 degrees, 300 kg of methanol was pumped in, stirred for 1 hour, cooled to 15 degrees, centrifuged, and dried to obtain 70.2 kg of product (purity 99.61%; yield 81.1%).

[0049] Comparative Example 1

[0050] 42.1 kg of BVPE (purity 99.25%; yield 48.6%) was prepared in the same manner as in Example 1, except that 15 kg of p-toluenesulfonic acid, 300 kg of chlorobenzene, 3 kg of pyridine and 100 kg of 4,4′-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) were used for the reaction.

[0051] Comparative Example 2

[0052] 68.7 kg of BVPE (purity 99.51%; yield 79.3%) was prepared in the same manner as Example 1, except that 15 kg of p-toluenesulfonic acid, 1000 kg of chlorobenzene, 15 kg of pyridine and 4,4'-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) were used for the reaction.

[0053] Comparative Example 3

[0054] 10.2 kg of BVPE (purity 95.04%; yield 11.8%) was obtained in the same manner as in Example 1, except that pyridine was not added to carry out the reaction.

[0055] It can be seen from the above Examples 1 to 6 and Comparative Examples 1 to 3 that the preparation methods within the scope of the present application all obtain BVPE with very high purity and yield, the reaction conditions are mild, the polymerization of olefins is reduced, and BVPE is synthesized with high yield. The present invention provides a simple and feasible method for synthesizing BVPE.

[0056] Among them, compared with Examples 1-6, Comparative Example 1-2 used a material ratio outside the scope specified in the present application, and the yield of BVPE decreased significantly. Comparative Example 3 did not add pyridine, which had a significant impact on the yield of BVPE and also had a significant impact on the purity of BVPE.

[0057] Advantages of the present invention: by introducing pyridine to change the acidic environment of the reaction system, the polymerization of olefins is effectively reduced, and the yield and purity of BVPE are improved. In addition, the raw materials of the present application are relatively easy to obtain and the production cost is greatly reduced, which further enhances the industrial application potential of the method and makes large-scale production of BVPE possible.

[0058] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for preparing BVPE, characterized in that: The method comprises dehydrating 4,4′-(1,2-ethanediyl)bis(α-methylbenzyl alcohol) to generate BVPE in the presence of reaction materials; the reaction materials comprise a pyridine-based catalyst, a p-toluenesulfonic acid-based catalyst and a chlorobenzene-based solvent.

2. The preparation method according to claim 1, characterized in that: The pyridine-based catalyst includes pyridine, collidine and tetramethylpyridine; the chlorobenzene-based solvent includes chlorobenzene, xylene and trimethylbenzene.

3. The preparation method according to claim 1, characterized in that: Chlorobenzene is used in an amount of 30-60 times the weight of toluenesulfonic acid and pyridine is used in an amount of 0.424-0.623 times the weight of p-toluenesulfonic acid. Preferably, 1 part by weight of p-toluenesulfonic acid, 40 parts by weight of chlorobenzene and 0.5 parts by weight of pyridine are used.

4. The preparation method according to claim 1, characterized in that: The preparation method comprises the steps of mixing p-toluenesulfonic acid, chlorobenzene and pyridine to obtain a mixed catalyst, adding 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol), and performing a dehydration reaction to obtain BVPE.

5. The preparation method according to claim 4, characterized in that: The method of mixing p-toluenesulfonic acid, chlorobenzene and pyridine to prepare a mixed catalyst comprises: mixing p-toluenesulfonic acid, chlorobenzene and pyridine and then heating to prepare a mixed catalyst, wherein the heating temperature is 35-45° C. The method of performing a dehydration reaction to obtain BVPE comprises: adding 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) and then performing a heating reflux reaction, wherein the reaction time is 2.5-3.5 hours, separating the liquids, and performing vacuum distillation on the upper layer to obtain BVPE.

6. The preparation method according to claim 5, characterized in that: The heating reflux reaction comprises the following steps: heating a mixed catalyst to which 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) is added for reflux reaction, separating generated water, detecting the raw material content to a preset value, cooling and adding water, stirring and then standing.

7. The preparation method according to claim 6, characterized in that: The temperature of the heating reflux reaction is 130-135° C.; the detection of the raw material content to a preset value is that the detection raw material content is less than 1%.

8. The preparation method according to claim 5, characterized in that: The vacuum distillation The method comprises the following steps: reducing the pressure on a mixed catalyst to which 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) is added to recover chlorobenzene, cooling and adding methanol, stirring and centrifuging to separate solids, and drying the solids.

9. The preparation method according to claim 8, characterized in that: The conditions for recovering chlorobenzene under reduced pressure are to collect fractions at 78-92°C under a pressure of 5.4-6.0 kPa; the temperature for adding methanol by cooling is 28-32°C, the stirring time is 50-70 min, and the centrifugal temperature is 13-17°C.

10. A method for preparing BVPE using 1,2-diphenylethane as raw material, characterized in that: The following steps are involved: S1, using 1,2-diphenylethane as a raw material, reacting in a solvent under the action of aluminum chloride and acetyl chloride to obtain 4,4'-diacetyl diaryl ethane; S2, under the action of sodium borohydride, 4,4'-diacetyl diaryl ethane reacts in a solvent to obtain 4,4'-(1,2-ethanedialkyl)bis(α-methylbenzyl alcohol); S3, p-toluenesulfonic acid, chlorobenzene and pyridine are mixed evenly and heated, 4,4'-(1,2-ethylenedialkyl)bis(α-methylbenzyl alcohol) is added to obtain a raw material mixture, and the mixture is heated under reflux for reaction for 2.5-3.5 hours, the liquids are separated, and the upper layer is vacuum distilled to obtain BVPE.

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