Preparation method of 4, 4 '-dibromo terphenyl

Abstract

The invention provides a preparation method of 4, 4 ''-dibromo terphenyl, which comprises the following steps: (1) mixing terphenyl and liquid bromine, and reacting under the action of a catalyst trichloride; and (2) washing the product obtained in the step (1) with a sodium hydrogen sulfite solution to obtain 4, 4 ''-dibromo terphenyl. The preparation method of the 4, 4 '-dibromo terphenyl has the beneficial effects that the dichloromethane is used as a solvent, and experiments verify that most impurities can be taken away by using the dichloromethane as the solvent, so that the purity of a final product is improved; the boiling point of dichloromethane is 39.8 DEG C, so that the temperature of the whole reaction system is constant and controllable, the operation process is simplified, and the production efficiency is improved; according to the preparation method of the 4, 4 ''-dibromo-terphenyl, bismuth trichloride is used as a catalyst, the dosage is small, and the catalytic efficiency is high; the 4, 4 '-dibromo-terphenyl obtained by the preparation method of the 4, 4'-dibromo-terphenyl is high in yield and purity, simple to operate and suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemical industry, and specifically relates to a method for preparing 4,4″-dibromoterphenyl. Background Art

[0002] 4,4″-dibromoterphenyl is a key organic chemical intermediate, widely used in the synthesis of high-performance polymers, fine chemicals and advanced materials. In particular, it plays an important role in the preparation of liquid crystal display materials, rubber and plastic industries, and high-performance engineering plastics and composite materials. This compound is not only crucial to improving the heat resistance, chemical resistance and mechanical strength of products, but also provides advanced material solutions in the development of next-generation display technology, automobile manufacturing, aerospace and other fields. With the advancement of science and technology, the application areas of 4,4″-dibromoterphenyl are expected to expand further, providing strong support for scientific and technological development and material innovation. However, the reaction conditions for the preparation of 4,4″-dibromoterphenyl in the existing technology are relatively harsh, and the temperature needs to be adjusted at different stages, which makes the operation complicated; the process of separating and purifying the product is complicated, and the production efficiency is low; the purity of the product is low. Summary of the invention

[0003] The present application provides a method for preparing 4,4″-dibromoterphenyl, aiming to solve the problems of complex process, low purity, great purification difficulty and high cost in the existing production of 4,4″-dibromoterphenyl.

[0004] The present application provides a method for preparing 4,4″-dibromoterphenyl, comprising the following steps:

[0005] (1) terphenyl and liquid bromine are mixed and reacted under the action of a catalyst, bismuth trichloride;

[0006] (2) washing the product obtained in step (1) with a sodium bisulfite solution to obtain 4,4″-dibromoterphenyl.

[0007] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, in step (1), the reaction is carried out in an organic solvent.

[0008] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the organic solvent includes dichloromethane. Dichloromethane has better solubility than other organic solvents and can take away most impurities, thereby improving the purity of the final product. In addition, the boiling point of dichloromethane is only 39.8°C, which is close to the ideal reaction temperature. The entire reaction temperature is easy to control and can be directly refluxed without using a thermocouple thermometer to adjust the temperature, which simplifies the operation process, thereby improving production efficiency and being suitable for mass production.

[0009] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the mass ratio of the terphenyl to the liquid bromine is 1:(2.1-2.3), for example, 1:2.1, 1:2.15, 1:2.2, 1:2.25, 1:2.3, etc.

[0010] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the mass ratio of the terphenyl to the catalyst is 200:(0.8-1.2), for example, 200:0.8, 200:0.85, 200:0.9, 200:1, 200:1.05, 200:1.2, etc.

[0011] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the mass ratio of the terphenyl to the organic solvent is 1:(2-3), for example, 1:2, 1:2.5, 1:2.65, 1:3, etc.

[0012] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the reaction temperature is 35-45°C, such as 35°C, 38°C, 40°C, 45°C, etc., and the reaction time is 5-8h, such as 5h, 6h, 7h, 8h, etc.

[0013] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the molar concentration of the sodium bisulfite solution is 0.4-0.6 mol / L, such as 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, etc.

[0014] According to some embodiments of the method for preparing 4,4″-dibromoterphenyl described in the present application, the molar concentration of the sodium bisulfite solution is 0.5 mol / L.

[0015] The beneficial effects of this application include at least:

[0016] 1. The method for preparing 4,4″-dibromoterphenyl described in the present application uses dichloromethane as a solvent. Experimental verification shows that using dichloromethane as a solvent can remove most impurities and improve the purity of the final product. Since the boiling point of dichloromethane is 39.8°C, the temperature of the entire reaction system is thermostatically controllable, which simplifies the operation process, thereby improving production efficiency and being suitable for mass production.

[0017] 2. The method for preparing 4,4″-dibromoterphenyl described in the present application uses bismuth trichloride as a catalyst, with a small amount and high catalytic efficiency.

[0018] 3. The method for preparing 4,4″-dibromoterphenyl described in this application has high yield, high purity, simple operation and is suitable for industrial production. DETAILED DESCRIPTION

[0021] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0022] Example 1

[0023] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0024] 200g of terphenyl was dissolved in 400ml of dichloromethane to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0025] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0026] Example 2

[0027] The difference between Example 2 and Example 1 is only that the amount of catalyst used is different.

[0028] The specific steps are:

[0029] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0030] 200 g of terphenyl was dissolved in 400 ml of dichloromethane to obtain a mixed solution, which was added to a 1 L glass reactor, followed by 0.8 g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140 ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0031] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0032] Example 3

[0033] The only difference between Example 3 and Example 1 is that the amount of catalyst used is different.

[0034] The specific steps are:

[0035] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0036] 200 g of terphenyl was dissolved in 400 ml of dichloromethane to obtain a mixed solution, which was added to a 1 L glass reactor, followed by 1.2 g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140 ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0037] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0038] Example 4

[0039] The only difference between Example 4 and Example 1 is that the mass ratio of terphenyl to liquid bromine is different.

[0040] The specific steps are:

[0041] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0042] 200g of terphenyl was dissolved in 400ml of dichloromethane to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 135ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0043] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0044] Example 5

[0045] The only difference between Example 5 and Example 1 is that the mass ratio of terphenyl to liquid bromine is different.

[0046] The specific steps are:

[0047] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0048] 200g of terphenyl was dissolved in 400ml of dichloromethane to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 145ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0049] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0050] Comparative Example 1

[0051] The only difference between Comparative Example 1 and Example 1 is that different organic solvents are used.

[0052] The specific operations are:

[0053] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0054] 200g of terphenyl was dissolved in 400ml of toluene to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of bismuth trichloride as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0055] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0056] Comparative Example 2

[0057] The only difference between Comparative Example 2 and Example 1 is that different organic solvents are used.

[0058] The specific operations are:

[0059] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0060] Dissolve 200g of terphenyl in 400ml of N,N-dimethylformamide to obtain a mixed solution, add the mixed solution into a 1L glass reactor, then add 1g of bismuth trichloride as a catalyst, control the temperature to 40°C, and add 140ml of liquid bromine through a constant pressure dropping funnel under stirring. The whole process takes 3 hours. After the addition is completed, continue the reflux reaction for 5 hours.

[0061] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0062] Comparative Example 3

[0063] The only difference between Comparative Example 3 and Example 1 is that different catalysts are used.

[0064] The specific operations are:

[0065] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0066] 200g of terphenyl was dissolved in 400ml of dichloromethane to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of iodine as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0067] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0068] Comparative Example 4

[0069] The only difference between Comparative Example 4 and Example 1 is that different catalysts are used.

[0070] The specific operations are:

[0071] A method for preparing 4,4″-dibromoterphenyl comprises the following steps:

[0072] 200g of terphenyl was dissolved in 400ml of dichloromethane to obtain a mixed solution, which was added to a 1L glass reactor, followed by 1g of ferric bromide as a catalyst, and the temperature was controlled at 40°C. Under stirring conditions, 140ml of liquid bromine was added dropwise through a constant pressure dropping funnel. The whole process took 3 hours. After the addition was completed, the reflux reaction was continued for 5 hours.

[0073] After the reaction is completed, the reaction liquid is fully cooled to room temperature and filtered to obtain a filter cake and a filtrate. The filter cake is washed with a 0.5M sodium bisulfite solution for 3 times, 500 ml each time, and then placed in an oven at a working temperature of 80°C to dry to obtain 4,4″-dibromoterphenyl. The shape is white powder crystal.

[0074] The yield and purity of 4,4″-dibromoterphenyl obtained by the preparation methods described in Examples 1-5 and Comparative Examples 1-4 of the present application are studied, and the results are shown in Table 1:

[0075] Wherein: The calculation method of 4,4″-dibromoterphenyl yield is the number of moles of final product 4,4″-dibromoterphenyl / the number of moles of raw material terphenyl

[0076] The purity of 4,4″-dibromoterphenyl was verified by H NMR, mass spectrometry, and elemental analysis.

[0077] Table 1

[0078]

[0079]

[0080] It can be seen from Table 1 that according to the preparation method of the present invention, the yield of 4,4″-dibromoterphenyl is about 94%; while using other organic solvents such as toluene and N,N-dimethylformamide, the reaction effect is not good, and the final yield is significantly lower than that of dichloromethane; using catalysts such as iodine and ferric bromide, the catalytic effect is significantly inferior to bismuth trichloride. Therefore, the solvent selection, catalyst selection and mass ratio of each raw material of the present invention are better than those of the existing preparation method, and the final yield is higher.

[0081] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A method for preparing 4,4″-dibromoterphenyl, characterized in that: The following steps are involved: (1) terphenyl and liquid bromine are mixed and reacted under the action of a catalyst, bismuth trichloride; (2) washing the product obtained in step (1) with a sodium bisulfite solution to obtain 4,4″-dibromoterphenyl.

2. The method for preparing 4,4″-dibromoterphenyl according to claim 1, characterized in that: In step (1), the reaction is carried out in an organic solvent; Preferably, the organic solvent comprises dichloromethane.

3. The method for preparing 4,4″-dibromoterphenyl according to claim 1 or 2, characterized in that: The mass ratio of the terphenyl to the liquid bromine is 1:(2.1-2.3).

4. The method for preparing 4,4″-dibromoterphenyl according to claim 3, characterized in that: The mass ratio of the terphenyl to the catalyst is 200:(0.8-1.2).

5. The method for preparing 4,4″-dibromoterphenyl according to claim 2, characterized in that: The mass ratio of the terphenyl to the organic solvent is 1:(2-3).

6. The method for preparing 4,4″-dibromoterphenyl according to claim 3, characterized in that: The reaction temperature is 35-45°C, and the reaction time is 5-8h.

7. The method for preparing 4,4″-dibromoterphenyl according to claim 3, characterized in that: The molar concentration of the sodium bisulfite solution is 0.4-0.6 mol / L.

8. The method for preparing 4,4″-dibromoterphenyl according to claim 3, characterized in that: The molar concentration of the sodium bisulfite solution is 0.5 mol / L.

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