3, 3 '-(2-methyl-6-methyl formate benzenesulfonyl)-biphenol as well as preparation method and application thereof

Abstract

The invention relates to 3, 3 '-(2-methyl-6-methyl formate benzenesulfonyl)-biphenol as well as a preparation method and application of the 3, 3'-(2-methyl-6-methyl formate benzenesulfonyl)-biphenol, and the 3, 3 '-(2-methyl-6-methyl formate benzenesulfonyl)-biphenol has the following structural formula. Different functional groups are introduced to biphenol, a new material is obtained, and compared with a traditional biphenol material, the novel material has better electrical conductivity, abrasion resistance, moisture resistance, cold resistance and the like, and can meet the requirements of different application scenes when used as a liquid crystal material.

Description

Technical Field

[0001] This invention relates to 3,3'-(2-methyl-6-carboxymethyl ester benzenesulfonyl)-biphenylhydroquinone, its preparation method, and its applications, belonging to the field of new materials technology. Background Technology

[0002] The most widely used synthetic liquid crystal material (LCP) currently available is polymerized biphenyl phenol, a conductive organic polymer primarily used in the electronics and semiconductor fields. However, existing liquid crystal materials have shortcomings in conductivity, abrasion resistance, moisture resistance, and cold resistance, failing to meet the requirements of applications in harsh environments. With advancements in science and technology, there is a need for liquid crystal materials with specific application scenarios and performance requirements.

[0003] Furthermore, the development of new liquid crystal materials requires the introduction of different functional groups onto biphenyl hydroquinone. A key technological barrier to introducing these functional groups is the coupling of aromatic hydrocarbons. The classic aromatic hydrocarbon coupling reaction is the Ubbelohde coupling method, where halogenated aromatic hydrocarbons are coupled at temperatures above 150°C under copper powder catalysis. This method suffers from numerous side reactions, low yield (60%), poor product color, and difficulty in purification. Summary of the Invention

[0004] This invention first provides a 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyl, having the following structural formula:

[0005] .

[0006] Furthermore, the preparation method of 3,3'-(2-methyl-6-carboxylate benzenesulfonyl)-biphenyl includes the following steps: 1) Methyl salicylic acid reacts with methanol to give methyl salicylate;

[0007] 2) Methyl salicylate reacts with dimethylaminothiocarbamate chloride and potassium hydroxide to give methyl 3-methyl-2-dimethylaminothiocarbamate.

[0008] 3) Methyl 3-methyl-2-dimethylaminothiobenzoate is obtained by intramolecular transposition reaction;

[0009] 4) Methyl 3-methyl-2-dimethylaminoformylthiobenzoate reacts with chlorine and water to give methyl 2-methyl-6-carboxylate benzenesulfonyl chloride;

[0010] 5) 2-Methyl-6-carboxylate benzenesulfonyl chloride and p-chloroanisole react to give 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone;

[0011] 6) 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone and sodium hydroxide react in the presence of a reducing agent and a palladium on carbon catalyst to give intermediate BP013-6;

[0012] 7) The intermediate BP013-6 reacts with hydrochloric acid to obtain the target product BP013.

[0013]

[0014] Furthermore, step 1) includes the following steps: 11) Methylsalicylic acid is dissolved in methanol, and sulfuric acid is added to react, controlling the reaction temperature at 50-70℃; 12) After the reaction in step 11) is completed, the reactants are allowed to stand and separate into layers. The upper layer is then transferred and added to a sodium bicarbonate solution for further reaction. 13. Step 12) After the reaction is complete, the reactants are allowed to stand and separate into layers. The lower layer is retained to obtain methyl methyl salicylate.

[0015] Furthermore, step 2) includes the following steps: 21) Add methyl methyl salicylate and potassium hydroxide solution to dimethylaminothiochloropropionate solution, and control the reaction temperature to not exceed 0℃; 22) After the reaction in step 21) is completed, water is added, crystals are precipitated, and solid-liquid separation is performed to obtain crude methyl 3-methyl-2-dimethylaminothiocarbamate. 23) Crude dimethylaminothiocarbamate was dissolved in methanol by heating, cooled and crystallized, and the solid and liquid were separated to obtain a filter cake. The filter cake was dried to obtain dimethylaminothiocarbamate.

[0016] Furthermore, step 3) includes the following steps: 31) Methyl dimethylaminothiobenzoate was dissolved in dodecane and reacted at 200°C for 6 hours under nitrogen protection. 32) After the reaction in step 31) is complete, let it stand and separate into layers. Take the lower layer to obtain methyl 3-methyl-2-dimethylaminoformylthiobenzoate.

[0017] Furthermore, step 4) includes the following steps: 41) Methyl 3-methyl-2-dimethylaminoformylthiobenzoate is mixed with dichloromethane and water, and chlorine gas is introduced to control the reaction temperature to not exceed 0°C; 42) After the reaction in step 41) is complete, heat to 20°C, let stand to separate the layers, wash the lower layer with water, and retain the lower layer to obtain methyl 2-methyl-6-carboxylate benzenesulfonyl chloride.

[0018] Furthermore, step 5) includes the following steps: 51) Dissolve p-chloroanisole in dichloromethane, add aluminum trichloride, and add 2-methyl-6-carboxylate benzenesulfonyl chloride under nitrogen protection, controlling the reaction temperature not to exceed 0℃; 52) After step 51) the reaction is complete, add water and hydrochloric acid, and control the reaction temperature at 10-20℃; 53) After the reaction in step 52) is complete, let it stand to separate into layers. Wash the lower layer with water and retain the lower layer to obtain a dichloromethane solution of methyl 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone.

[0019] Furthermore, step 6) includes the following steps: 61) Add palladium on carbon and sodium hydroxide solution to a dichloromethane solution of methyl 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone; add a reducing agent, formic acid, under nitrogen protection, and control the reaction temperature at 35-40℃. 62) The reactants are cooled to below 30°C, and the solid and liquid are separated to obtain the filtrate. The filtrate is washed with water to obtain a dichloromethane solution of intermediate BP013-6.

[0020] Furthermore, step 7) includes the following steps: 71) Add sodium iodide, water, and hydrochloric acid to the dichloromethane solution of intermediate BP013-6; control the reaction temperature at 30-50℃; 72) After the reaction in step 71) is completed, the temperature is lowered to below 30°C, and the mixture is allowed to stand and separate into layers. The lower layer is washed with water, concentrated under reduced pressure, dissolved by heating with ethanol, cooled to crystallize, and the solid and liquid are separated to obtain a filter cake. The filter cake is dried to obtain BP013.

[0021] This invention claims protection for the use of 3,3'-(2-methyl-6-carboxymethyl ester benzenesulfonyl)-biphenyldiol in liquid crystal materials.

[0022] The advantages of this invention are as follows: By introducing different functional groups onto biphenyl hydroquinone, a new material is obtained, which exhibits better conductivity, wear resistance, moisture resistance, and cold resistance compared to traditional materials. As a liquid crystal material, it can meet the requirements of various application scenarios. This solves the technical problem that existing liquid crystal materials cannot be used in harsh climates or environments.

[0023] Furthermore, this invention utilizes palladium on carbon as a catalyst and adds a reducing agent under alkaline conditions, achieving high yield (over 85%) of halogenated aromatic hydrocarbon coupling under mild conditions. The method of this invention is low-cost and produces high-purity products (chromatographic purity ≥99.5%), meeting the requirements of special liquid crystal materials. The material prepared using the method of this invention exhibits superior yield and quality compared to traditional processes and materials.

[0024] According to the method of this invention, the production process can be fully automated, which greatly reduces the intensity of manual labor while ensuring more stable product quality compared with traditional chemical production processes. It improves efficiency while reducing energy consumption and raw material consumption. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] The present invention synthesizes the target product according to the following steps: I. Esterification reaction 1) Fix a 500ml three-necked flask in a heat-collecting magnetic stirrer, and equip it with a thermometer, condenser, and 100ml constant pressure funnel; 2) Add 185g of methanol to the flask, turn on the magnetic stirrer, and add 100g of methyl salicylic acid in batches until it is completely dissolved by visual inspection; 3) Add 120g of sulfuric acid to the constant pressure funnel; 4) Set the water bath temperature to 80℃ and heat it to 50-70℃ inside the flask. Begin adding sulfuric acid dropwise; 5) After adding sulfuric acid, continue the reaction at this temperature for 5 hours. HPLC analysis shows that if the residual raw material is ≤8%, the reaction is considered complete.

[0027] 6) Remove the hot water from the water bath, add tap water, and lower the temperature inside the flask to below 50℃. Turn off the magnetic stirrer, transfer the reaction solution into a 500ml separatory funnel, and let it stand for 30 minutes to separate the layers. Collect the lower sulfuric acid layer, and add the prepared 6% sodium bicarbonate solution to the upper layer (add 100ml water to a 250ml beaker, add 6.5g of sodium bicarbonate, and stir with a glass rod to dissolve). Shake up and down 3 times, let it stand for 15 minutes, and separate the layers. 7) Lower layer, weigh the material to obtain BP013-1 (methyl methyl salicylate), take a sample and send it for testing.

[0028] II. Acylation reaction 1) Fix a 1000ml four-necked flask in a water chiller, and install a -50~50℃ mercury thermometer, mechanical stirrer, and 250ml constant pressure leak; 2) Set the water chiller temperature to -15℃ and start the flask stirrer. Add 275g of dimethylaminothiochloroacetone solution and 100g of BP013-1 to the flask; 3) Add 180g of 33.33% potassium hydroxide solution (60g of potassium hydroxide dissolved in 120g of water) to the constant pressure funnel; 4) When the temperature inside the flask drops below 0°C, begin adding potassium hydroxide solution dropwise. During this process, maintain the temperature below 0°C. 5) After adding potassium hydroxide, continue the reaction at this temperature for 1 hour. Add 200 ml of water, allow crystals to precipitate for 1 hour, filter using a Buchner funnel, collect the filter cake, and transfer the filtrate to a wastewater tank.

[0029] BP013-2 Refined 1) Fix a 500ml three-necked flask on a water bath, and equip it with a mechanical stirrer, a 100℃ thermometer, and a reflux condenser; 2) Add 200g of methanol to the flask, start stirring, and add the wet filter cake; 3) Set the water bath temperature to 80℃, raise the temperature to 50-70℃ in the flask, keep it warm for 1 hour, remove the hot water, cool the tap water to 40℃, filter with a Buchner funnel, collect the filter cake, and put the filtrate into the wastewater tank. 4) The filter cake is placed in a hot air circulating oven at a temperature of 60-65℃, with a moisture content of ≤0.5%, which is considered drying. It is weighed to obtain BP013-2 (methyl-2-dimethylaminothiocarbamoylbenzoate), and a sample is sent for testing.

[0030] III. Intramolecular Translocation 1) Fix a 1000ml four-necked flask in a heat-collecting oil heating pot, and equip it with a 300℃ thermometer, mechanical stirrer, reflux condenser, and nitrogen gas supply tube. Connect the nitrogen supply tube to the nitrogen cylinder with a flexible hose; 2) Add 200g of dodecane to the flask, start stirring, add 144g of BP013-2, and slowly open the nitrogen cylinder. Set the oil heating temperature to 250℃ and begin heating. 3) When the temperature inside the flask reaches 200℃, continue to maintain the temperature for 6 hours; 4) Remove the oil bath, stop stirring, and let stand for 3 hours to allow the layers to separate. 5) Bottle the lower layer of product, weigh it to obtain BP013-3 (methyl 3-methyl-2-dimethylaminoformylthiobenzoate), and send a sample for testing. Collect the upper layer and reuse it.

[0031] IV. Acyl chloride reaction 1) Fix a 500ml four-necked flask in a water chiller and install a -50~50 red mercury thermometer, mechanical stirrer, chlorine tube, and tail gas alkali absorption tube; 2) Add 200g of dichloromethane and 100g of water to the flask. Turn on the stirrer and add 136g of BP013-3; 3) Chiller temperature set to -15℃. Zero the chlorine metering electronic scale; 4) When the temperature inside the flask drops below 0°C, slowly open the chlorine cylinder to begin releasing chlorine gas. During this process, maintain the temperature inside the flask below 0°C. 5) When the chlorine gas input reaches 125g, close the chlorine gas valve. Remove the chiller and switch to a water bath, setting the water bath temperature to 20℃. Continue stirring for 2 hours, then turn off the stirrer. Transfer the mixture to a 500ml separatory funnel to separate the layers. Add 100ml of water to the lower layer, wash once, and transfer to a 1000ml four-necked flask. Transfer the upper layer to a wastewater tank.

[0032] V. Friedel-Crafts Reaction 1) Fix a 1000ml four-necked flask in a chiller and install a -50~50℃ mercury thermometer, mechanical stirrer, 250ml constant pressure funnel, and nitrogen short tube; 2) Set the chiller temperature to -15℃. Add 100g of dichloromethane and 55g of p-chloroanisole to the flask. Stir the flask and add 102g of aluminum trichloride. Add the reaction solution from the previous step to the constant pressure funnel. Open the nitrogen cylinder for nitrogen protection. 3) When the temperature inside the flask drops below 0°C, add BP013-4 (2-methyl-6-carboxylate benzenesulfonyl chloride)-dichloromethane solution dropwise. During this process, control the temperature inside the flask to ensure it does not exceed 0°C. 4) After adding the BP013-4 dichloromethane solution, continue the reaction at the temperature for 6 hours.

[0033] 5) Add 150g of water to the flask and 65g of hydrochloric acid to the constant pressure funnel; 6) Set the chiller to 0℃. When the temperature inside the flask reaches 5℃, begin adding hydrochloric acid. During this process, maintain the temperature between 10-20℃. 7) After adding hydrochloric acid, transfer the reaction solution into a 1000ml separatory funnel, let it stand for 15 minutes to separate the layers. Add 100g of water to the next layer and wash once.

[0034] VI. Coupling Reaction 1) Fix four 1000ml flasks on the heat-collecting water bath, and install a 100℃ thermometer, a reflux condenser, a 50ml constant pressure funnel, and a nitrogen-purging short tube. 2) Add the reaction solution from the previous step to the flask, turn on the stirrer, and continue to add 0.5g of palladium on carbon and 205g of 10% sodium hydroxide solution; 3) Set the hot water boiler temperature to 50℃, open the nitrogen cylinder, and activate nitrogen protection; 4) Add 16.5g of reducing agent to the constant pressure funnel. When the temperature inside the flask reaches 35℃, begin adding the reducing agent dropwise; 5) After adding the reducing agent, continue to maintain the temperature at 35-40℃ for 5 hours; 6) Remove the hot water and cool the reaction solution to below 30°C with tap water; 7) Filter using a Buchner funnel, collect the filter cake on palladium carbon in a bag, and wash the filtrate once with 150g of water.

[0035] 8) The molar yield of the product is >85%, which is 25% higher than that of the traditional coupling method (average 60%).

[0036] VII. Hydrolysis reaction 1) Secure a 1000ml three-necked flask to a heat-collecting magnetic stirrer and install a 100℃ thermometer and condenser. 2) Add the reaction solution from the previous step to the flask, open the flask and stir, then add 3.5g of sodium iodide, 100g of water and 32g of hydrochloric acid; 3) Set the water bath temperature to 50℃, raise it to 30-50℃, and react for 12 hours; 4) Remove the hot water and replace it with tap water to cool to below 30℃. Transfer the cooled liquid to a 1000ml separatory funnel and let it stand for 15 minutes to separate the layers. Add 100g of water to the lower layer, wash once, and transfer to a 1000ml flask. Administer the upper layer to a wastewater container. 5) Turn on the water pump, adjust the vacuum level to -0.08 to -0.085, and concentrate under reduced pressure until the temperature inside the flask reaches 85°C; 6) Remove the hot water and cool it with tap water. When the temperature inside the flask reaches 50°C, add 300g of ethanol. 7) Heat to above 50℃, hold for 1 hour, remove the hot water, and cool with ice water instead. Allow to crystallize for 10 hours below 20℃. 8) Filter using a Buchner funnel and collect the filter cake. Dry in a 65℃ hot air circulating oven to obtain BP013, and take samples for testing.

[0037] Example 1 Formic acid was used as the reducing agent in the coupling reaction. The product yield was 85%, and the purity, as determined by chromatography, was 99.5%. The product quality is as follows:

[0038] Traditional Ubbelohde coupling method – high-temperature coupling of halogenated aromatics catalyzed by copper powder. Product molar yield 60%, chromatographic purity >98%.

[0039] The liquid crystal material synthesized by thermal polymerization of the modified biphenyl obtained in Example 1 shows the following performance improvement compared to the traditional thermally polymerized biphenyl liquid crystal material:

Claims

1,3,3'-(2-methyl-6-carboxymethyl ester benzenesulfonyl)-biphenyl, characterized in that, It has the following structural formula: 。 2. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 1, characterized in that, Includes the following steps: 1) Methyl salicylic acid reacts with methanol to give methyl salicylate; 2) Methyl salicylate reacts with dimethylaminothiocarbamate chloride and potassium hydroxide to give methyl 3-methyl-2-dimethylaminothiocarbamate. 3) Methyl 3-methyl-2-dimethylaminothiobenzoate is obtained by intramolecular transposition reaction; 4) Methyl 3-methyl-2-dimethylaminoformylthiobenzoate reacts with chlorine and water to give methyl 2-methyl-6-carboxylate benzenesulfonyl chloride; 5) 2-Methyl-6-carboxylate benzenesulfonyl chloride and p-chloroanisole react to give 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone; 6) 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone and sodium hydroxide react in the presence of a reducing agent and a palladium on carbon catalyst to give the intermediate BP013-6 with the following structural formula; 7) The intermediate BP013-6 reacts with hydrochloric acid to obtain the target product BP013.

3. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 2, characterized in that, Step 1) includes the following steps: 11) Methylsalicylic acid is dissolved in methanol, and sulfuric acid is added to react, controlling the reaction temperature at 50-70℃; 12) After the reaction in step 11) is completed, the reactants are allowed to stand and separate into layers. The upper layer is then transferred and added to a sodium bicarbonate solution for further reaction.

13. Step 12) After the reaction is complete, the reactants are allowed to stand and separate into layers. The lower layer is retained to obtain methyl methyl salicylate.

4. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 2, characterized in that, Step 2) includes the following steps: 21) Add methyl methyl salicylate and potassium hydroxide solution to dimethylaminothiochloropropionate solution, and control the reaction temperature to not exceed 0℃; 22) After the reaction in step 21) is completed, water is added, crystals are precipitated, and solid-liquid separation is performed to obtain crude methyl 3-methyl-2-dimethylaminothiocarbamate. 23) Crude dimethylaminothiocarbamate was dissolved in methanol by heating, cooled and crystallized, and the solid and liquid were separated to obtain a filter cake. The filter cake was dried to obtain dimethylaminothiocarbamate.

5. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 2, characterized in that, Step 3) includes the following steps: 31) Methyl dimethylaminothiobenzoate was dissolved in dodecane and reacted at 200°C for 6 hours under nitrogen protection. 32) After the reaction in step 31) is complete, let it stand and separate into layers. Take the lower layer to obtain methyl 3-methyl-2-dimethylaminoformylthiobenzoate.

6. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 2, characterized in that, Step 4) Includes the following steps: 41) Methyl 3-methyl-2-dimethylaminoformylthiobenzoate is mixed with dichloromethane and water, and chlorine gas is introduced to control the reaction temperature to not exceed 0°C; 42) After the reaction in step 41) is complete, heat to 20°C, let stand to separate the layers, wash the lower layer with water, and retain the lower layer to obtain methyl 2-methyl-6-carboxylate benzenesulfonyl chloride.

7. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 2, characterized in that, Step 5) includes the following steps: 51) Dissolve p-chloroanisole in dichloromethane, add aluminum trichloride, and add 2-methyl-6-carboxylate benzenesulfonyl chloride under nitrogen protection, controlling the reaction temperature not to exceed 0℃; 52) After step 51) the reaction is complete, add water and hydrochloric acid, and control the reaction temperature at 10-20℃; 53) After the reaction in step 52) is complete, let it stand to separate into layers. Wash the lower layer with water and retain the lower layer to obtain a dichloromethane solution of methyl 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone.

8. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 7, characterized in that, Step 6) includes the following steps: 61) Add palladium on carbon and sodium hydroxide solution to a dichloromethane solution of methyl 2-methyl-6-benzoate-4'-chloro-6'-methoxysulfone; add a reducing agent, formic acid, under nitrogen protection, and control the reaction temperature at 35-40℃. 62) The reactants are cooled to below 30°C, and the solid and liquid are separated to obtain the filtrate. The filtrate is washed with water to obtain a dichloromethane solution of intermediate BP013-6.

9. The method for preparing 3,3'-(2-methyl-6-carboxylic acid methyl ester benzenesulfonyl)-biphenyldiol according to claim 8, characterized in that, Step 7) includes the following steps: 71) Add sodium iodide, water, and hydrochloric acid to the dichloromethane solution of intermediate BP013-6; control the reaction temperature at 30-50℃; 72) After the reaction in step 71) is completed, the temperature is lowered to below 30°C, and the mixture is allowed to stand and separate into layers. The lower layer is washed with water, concentrated under reduced pressure, dissolved by heating with ethanol, cooled to crystallize, and the solid and liquid are separated to obtain a filter cake. The filter cake is dried to obtain BP013.

10. The application of 3,3'-(2-methyl-6-carboxymethyl ester benzenesulfonyl)-biphenyldiol as described in claim 1 in liquid crystal materials.

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