Method for massively synthesizing diaryl methane compounds and application of diaryl methane compounds

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing a large number of diaryl methane compounds and application of the diaryl methane compounds. The synthesis method comprises the following steps: firstly, putting a phenyl alcohol reactant and an aromatic hydrocarbon reactant into an organic solvent, then adding a catalyst under a stirring condition to react, and after the reaction is finished, removing the organic solvent and the residual aromatic hydrocarbon reactant through rotary evaporation to obtain a crude product; and carrying out silica gel column chromatography separation and purification on the crude product to obtain the diaryl methane compound. The phenyl alcohol reactants which are low in toxicity, wide in source and rich in structure and the acid catalyst which is low in cost and easy to obtain are selected, the method is mild in condition and high in raw material conversion rate, the byproduct is safe and nontoxic water, the diaryl methane compound can be prepared in a large scale, and the method is suitable for industrial production. The diaryl methane compound obtained by the invention can be directly used as a high-low temperature lubricating material to be applied to the field of organic heat carriers.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing diarylmethane compounds in large quantities and its application. Background Art

[0002] Diarylmethane is a constituent structural unit of some bioactive pharmaceutical molecules and natural products. Diarylmethane derivatives have wide applications in the fields of pharmacologically active compounds and functional materials, and their synthesis has always been of great importance in the field of organic chemistry. The Friedel-Crafts benzylation reaction of aromatic hydrocarbons is one of the traditional methods for synthesizing diarylmethane derivatives. In its traditional form, this reaction is catalyzed by strong Lewis acids (such as AlCl 3 and FeCl 3 ), and due to the inhibitory effect of the product, a large amount of catalyst is required. In addition, this reaction uses toxic halogenated hydrocarbons as raw materials and is prone to hydrolysis to produce irritating halogenated acid gas by-products. Therefore, from the perspectives of atom economy and green chemistry, these reaction conditions are far from ideal.

[0003] When considering improving the traditional Friedel-Crafts benzylation reaction, alcohol reactants have become attractive excellent electrophilic reagents due to their low toxicity, high stability, wide availability, and easy preparation. In addition, from the perspective of green chemistry, when alcohols participate in substitution reactions, water is usually the only by-product. Since the first proposal to use benzyl alcohol to replace aromatic hydrocarbons in 1986, the Friedel-Crafts reactions of aromatic hydrocarbons with activated benzyl alcohols and halides catalyzed by metal salts such as TeCl 4 , Sc(OTf) 3 , FeCl 3 , Bi(OTf) 3 and HAuCl 4 have been reported. Crousse et al. reported the Friedel-Crafts benzylation reaction of potassium bisulfate in synergy with hexafluoroisopropanol. The hydrogen bond donor catalytic system formed by inexpensive and readily available acidic catalysts and solvents has shown good effects in promoting the reaction of phenyl alcohols and aromatic hydrocarbons. This reaction system is efficient, mild in conditions, and low in cost of raw materials and catalysts, and is expected to provide a method for preparing diarylmethane compounds in large quantities, which is of great significance for the development and industrial application of the structures and properties of diarylmethane compounds. Summary of the Invention

[0004] The object of the present invention is to provide a method for synthesizing diarylmethane compounds in large quantities, which has mild reaction conditions, simple process, high raw material conversion rate, and good reaction yield. In addition, the present invention also provides the application of diarylmethane compounds as high and low temperature lubricating materials in the field of organic heat carriers.

[0005] The method for synthesizing a large amount of diarylmethane compounds according to the present invention comprises the following steps:

[0006] (1) First, place the phenyl alcohol reactant and the aromatic hydrocarbon reactant in an organic solvent, then add a catalyst under stirring for reaction. After the reaction is completed, remove the organic solvent and the remaining aromatic hydrocarbon reactant by rotary evaporation to obtain a crude product;

[0007] (2) Subject the crude product obtained in step (1) to silica gel column chromatography for separation and purification to obtain diarylmethane compounds;

[0008] Wherein:

[0009] The general structural formula of the diarylmethane compounds prepared in step (2) is as shown in formula (I):

[0010]

[0011] In the said formula (I), R 1 and R 3 are each independently selected from any one of the following chemical structural formulas 1-10; R 2 is selected from any one of the following chemical structural formulas 11;

[0012]

[0013] Wherein, i and j are integers from 2 to 20, k is an integer from 0 to 20; X is selected from one of Br element, nitrile group or amino group; Y 1 and Y 2 are each independently selected from one of F element, Cl element, Br element, I element, nitrile group or phenyl group; Z is selected from one of O or S elements; * represents the substitution position.

[0014] The organic solvent described in step (1) is one or more of perfluorotert-butanol, hexafluoro-2,3-bis(trifluoromethyl)-2,3-diol, 2,2,2-trifluoroethanol, 1-phenyl-2,2,2-trifluoroethanol, 2,6-difluorobenzaldehyde, 2-perfluorooctylethanol or perfluorohexylethyl alcohol, preferably perfluorotert-butanol.

[0015] The catalyst described in step (1) is one or more of trifluoroacetic acid, trifluoroacetic anhydride or fluorophosphoric acid, preferably trifluoroacetic acid.

[0016] Wherein:

[0017] The general structural formula of the phenyl alcohol reactant described in step (1) is as shown in formula (II):

[0018]

[0019] The general structural formula of the aromatic hydrocarbon reactant described in step (1) is shown in formula (III):

[0020] R 3 -H (III);

[0021] In the said formulas (II)-(III), R 1 and R 3 are each independently selected from any one of the following chemical structural formulas 1-10; R 2 is selected from any one of the following chemical structural formulas 11;

[0022]

[0023] wherein, i and j are integers from 2 to 20, k is an integer from 0 to 20; X is selected from one of Br element, cyano group or amino group; Y 1 and Y 2 are each independently selected from one of F element, Cl element, Br element, I element, cyano group or phenyl group; Z is selected from one of O or S element; * represents the substitution position.

[0024] In step (1), the molar ratio of the phenyl alcohol reactant to the aromatic hydrocarbon reactant is 1:1.1 - 10, and further preferably 1:1.5 - 6.

[0025] In step (1), the concentration of the phenyl alcohol reactant in the organic solvent is 0.1 - 8 mol / L, and further preferably 0.4 - 5 mol / L.

[0026] In step (1), the dosage of the catalyst is 2 - 60 mol% of the phenyl alcohol reactant, and further preferably 5 - 20 mol%.

[0027] In step (1), the reaction temperature is 5 - 150 °C, preferably 20 - 100 °C, and the reaction time is 0.2 - 72 h, preferably 0.5 - 24 h.

[0028] Preferably, the method for synthesizing diarylmethane compounds in large quantities according to the present invention comprises the following steps:

[0029] (1) Take a single-necked flask and add a magnetic stirrer. Add the phenyl alcohol reactant and the aromatic hydrocarbon reactant thereto respectively, then add the organic solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the organic solvent. While stirring, add the catalyst to the reaction system to make the catalyst disperse evenly; then connect a condenser (it is necessary to apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to a constant temperature under stirring, after reacting for a period of time, stop the reaction, and rotary evaporate the organic solvent and the excessive aromatic hydrocarbon reactant in the filtrate to obtain the corresponding crude product;

[0030] (2) Subject the concentrated crude product obtained in step (1) to wet column loading, separate and purify it by silica gel column chromatography, judge by TLC to obtain a pure product solution, then remove the solvent by rotary evaporation and further dry it under vacuum to obtain a pure diarylmethane compound.

[0031] The application of the method for synthesizing a large amount of diarylmethane compounds according to the present invention is to use them as high and low temperature lubricating materials in the field of organic heat carriers.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The method for synthesizing a large amount of diarylmethane compounds according to the present invention optimizes the traditional Friedel-Crafts reaction conditions. Under the synergistic hydrogen bonding of an acidic catalyst and a solvent molecule, a phenyl alcohol reactant with low toxicity, high stability and wide accessibility is selected, which reacts with aromatic hydrocarbons gently and efficiently to prepare a large amount of diarylmethane compounds.

[0034] (2) The method for synthesizing a large amount of diarylmethane compounds according to the present invention has a wide range of sources of phenyl alcohol reactants, rich structures, and is easy to obtain various functionalized diarylmethane compounds, which can meet the demand for the diversity of diarylmethane compound types.

[0035] (3) The method for synthesizing a large amount of diarylmethane compounds according to the present invention has mild reaction conditions, simple process, is carried out in an atmospheric atmosphere, has simple synthesis operation, saves energy, has high raw material conversion rate, good reaction yield, the by-product is water, is safe and non-toxic, has good product quality, is convenient for industrial production, and can meet the market demand with a large quantity and wide range.

[0036] (4) The application of the method for synthesizing a large amount of diarylmethane compounds according to the present invention is to use the prepared diarylmethane compounds as high and low temperature lubricating materials in the field of organic heat carriers, making up for the limitations of the types of high and low temperature synthetic organic heat carriers, and having potential application prospects in industries such as photovoltaic power generation, cold storage, medical equipment, and low temperature heat transfer equipment. Description of the Drawings

[0037] Figure 1 1H NMR spectrum of the diarylmethane compound prepared in Example 1 of the present invention in deuterated chloroform;

[0038] Figure 2 13C NMR spectrum of the diarylmethane compound prepared in Example 1 of the present invention in deuterated chloroform;

[0039] Figure 3 UV-Vis absorption spectrum of the diarylmethane compound prepared in Example 1 of the present invention. Detailed Embodiments

[0040] The present invention will be further described below in conjunction with embodiments.

[0041] Example 1

[0042] The method for synthesizing a large amount of diarylmethane compounds described in this Example 1 consists of the following steps:

[0043] (1) Take a 1L single-necked flask, add a magnetic stirrer, and add benzyl alcohol (34.61 g, 0.32 mol) and ethylbenzene (203.85 g, 1.92 mol) thereto. Then add 320 mL of a perfluorotert-butanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add a trifluoroacetic acid catalyst (3.65 g, 0.032 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (it is necessary to apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 20 °C under stirring, react for 0.5 hour, and then stop the reaction. Filter the obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0044] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography. Spot plate to judge the separation to obtain a pure product solution, and then rotary evaporate to obtain a pure product, and further dry it under vacuum to obtain 49.37 g of pure diarylmethane compounds, with a yield of 78.6%.

[0045] Upon measurement and analysis, the nuclear magnetic resonance hydrogen spectrum of the diarylmethane compounds obtained in this Example 1 is shown in Figure 1 . Figure 1 Among them, the characteristic peaks at chemical shifts of 7.04 - 7.34 ppm correspond to the hydrogen atoms on the benzene ring in the structure of the diarylmethane compounds, the characteristic peaks at chemical shifts of 4.00 ppm and 4.07 ppm correspond to the hydrogen atoms on the methylene group between the two benzene rings in the structure of the diarylmethane compounds, the characteristic peak near a chemical shift of 2.67 ppm corresponds to the hydrogen atoms on another methylene group in the structure of the diarylmethane compounds, and the characteristic peaks at chemical shifts of 1.19 - 1.38 ppm correspond to the methyl hydrogen atoms in the structure of the diarylmethane compounds. Figure 1 This further confirms the successful progress of the reaction. Figure 2This is the carbon-13 nuclear magnetic resonance spectrum of the diarylmethane compound prepared in Example 1. The characteristic peaks at chemical shifts of 138.36 - 142.47 ppm correspond to the carbon atoms on the benzene ring connected to the methylene group in the product structure. The characteristic peaks at chemical shifts of 125.91 - 130.35 ppm correspond to the remaining carbon atoms on the benzene ring in the product structure. The characteristic peaks at chemical shifts of 76.75 ppm, 77.07 ppm, and 77.38 ppm correspond to the carbon atoms on deuterated chloroform as the solvent. The characteristic peaks at chemical shifts of 38.79 ppm and 41.57 ppm correspond to the carbon atoms on the methylene group between the two benzene rings in the product structure. The characteristic peaks at chemical shifts of 25.77 ppm and 28.48 ppm correspond to the carbon atoms on another methylene group in the product structure. The characteristic peaks at chemical shifts of 14.86 ppm and 15.70 ppm correspond to the methyl carbon atoms in the product structure. Figure 1 and Figure 2 further confirmed the successful progress of this reaction. Figure 3 This is the ultraviolet-visible absorption spectrum of the diarylmethane compound prepared in Example 1. This compound has absorption near 225 nm and 263 nm at the center, which corresponds to the K absorption band and B absorption band of aromatic compounds and is the characteristic peak of the benzene ring. This diarylmethane compound is easily soluble in organic solvents at room temperature, indicating excellent solubility. In addition, the pour point of this diarylmethane compound is -80 °C, and the distillation temperature at 2% is up to 290 °C, indicating excellent high and low temperature resistance characteristics and having broad application prospects in the field of high and low temperature lubricating oils.

[0046] Example 2

[0047] The method for synthesizing a large amount of diarylmethane compounds described in this Example 2 consists of the following steps:

[0048] (1) Take a 500 mL single-necked flask, add a magnetic stirrer, and add benzyl alcohol (34.61 g, 0.32 mol) and ethylbenzene (135.89 g, 1.28 mol) to it respectively. Then add 107 mL of 2,2,2-trifluoroethanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent; while stirring, add trifluoroacetic anhydride (10.09 g, 0.048 mol) to the reaction system to disperse the catalyst evenly; then connect a condenser (it is necessary to apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 80 °C under stirring, stop the reaction after reacting for 24 hours; filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0049] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography; judge by TLC to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum. 35.36 g of pure diarylmethane compound is obtained, and the yield is 56.3%. The freezing point of this diarylmethane compound is -80 °C, and the distillation temperature at 2% is up to 290 °C, indicating excellent high and low temperature resistance characteristics and broad application prospects in the field of high and low temperature lubricating oils.

[0050] Example 3

[0051] The method for synthesizing a large amount of diarylmethane compounds described in this Example 3 consists of the following steps:

[0052] (1) Take a 250 mL single-necked flask, add a magnetic stirrer, and add benzyl alcohol (34.61 g, 0.32 mol) and ethylbenzene (50.96 g, 0.48 mol) to it respectively. Then add 64 mL of 2,6-difluorobenzaldehyde solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent; while stirring, add a fluorophosphoric acid catalyst (1.60 g, 0.016 mol) to the reaction system to make the catalyst disperse evenly; then connect a condenser (it is necessary to apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, and react the reaction system at 70 °C with stirring for 8 hours, and then stop the reaction; filter the original reaction solution obtained above, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0053] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography; judge by TLC to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum. 41.27 g of diarylmethane compound is obtained, and the yield is 65.7%. The freezing point of this diarylmethane compound is -80 °C, and the distillation temperature at 2% is up to 290 °C, indicating excellent high and low temperature resistance characteristics and broad application prospects in the field of high and low temperature lubricating oils.

[0054] Example 4

[0055] The method for synthesizing a large amount of diarylmethane compounds described in this Example 4 consists of the following steps:

[0056] (1) Take a 2L single-necked flask, add a magnetic stir bar, and add benzyl alcohol (34.61 g, 0.32 mol) and ethylbenzene (101.92 g, 0.96 mol) to it. Then add 800 mL of perfluorohexylethyl alcohol solvent. Turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add trifluoroacetic acid catalyst (7.30 g, 0.064 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 100 °C with stirring, react for 12 hours, and then stop the reaction. Filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0057] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography. Spot the plate to judge the separation to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum to obtain 45.79 g of diarylmethane compound with a yield of 72.9%. The freezing point of this diarylmethane compound is -80 °C, and the distillation temperature at 2% is up to 290 °C, indicating excellent high and low temperature resistance characteristics and broad application prospects in the field of high and low temperature lubricating oils.

[0058] Example 5

[0059] The method for synthesizing a large amount of diarylmethane compounds described in this Example 5 consists of the following steps:

[0060] (1) Take a 1L single-necked flask, add a magnetic stir bar, and add benzyl alcohol (34.61 g, 0.32 mol) and butylbenzene (214.75 g, 1.6 mol) to it. Then add 160 mL of perfluorotert-butanol solvent. Turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add trifluoroacetic acid catalyst (2.92 g, 0.0256 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 40 °C with stirring, react for 6 hours, and then stop the reaction. Filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess butylbenzene in the filtrate to obtain the corresponding crude product;

[0061] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography; after spotting the plate to judge that a pure product solution has been separated, perform rotary evaporation to obtain the pure product, and further dry it under vacuum to obtain 58.43 g of the diarylmethane compound with a yield of 81.4%. The freezing point of this diarylmethane compound is -90 °C, and the distillation temperature at 2% is up to 320 °C, indicating excellent high and low temperature resistance characteristics and broad application prospects in the field of high and low temperature lubricating oils.

[0062] Example 6

[0063] The method for synthesizing a large amount of diarylmethane compounds described in this Example 6 consists of the following steps:

[0064] (1) Take a 500 mL single-necked flask, add a magnetic stirrer, and add styrene glycol (39.09 g, 0.32 mol) and ethylbenzene (135.90 g, 1.28 mol) to it respectively. Then add 80 mL of a perfluorotert-butanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent; while stirring, add a trifluoroacetic acid catalyst (3.65 g, 0.032 mol) to the reaction system to make the catalyst disperse evenly; then connect a condenser (it is necessary to apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 60 °C with stirring, react for 4 hours, and then stop the reaction; filter the original reaction solution obtained above by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excessive ethylbenzene in the filtrate to obtain the corresponding crude product;

[0065] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography; spot the plate to judge that a pure product solution has been separated, then perform rotary evaporation to obtain the pure product, and further dry it under vacuum to obtain 49.73 g of the diarylmethane compound with a yield of 73.9%. The freezing point of this diarylmethane compound is -118 °C, and the distillation temperature at 2% is up to 160 °C, indicating excellent low temperature resistance characteristics and broad application prospects in the field of low temperature lubricating oils.

[0066] Example 7

[0067] The method for synthesizing a large amount of diarylmethane compounds described in this Example 7 consists of the following steps:

[0068] (1) Take a 250 mL single-necked flask, add a magnetic stir bar, and add 3-(hydroxymethyl)benzonitrile (1.33 g, 0.01 mol) and ethylbenzene (4.25 g, 0.04 mol) thereto. Then add 100 mL of high-fluorotert-butanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add trifluoroacetic acid catalyst (0.12 g, 0.001 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 50 °C under stirring, react for 16 hours, and then stop the reaction. Filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0069] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography. Spot the plate to judge the separation to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum to obtain 1.35 g of diarylmethane compound with a yield of 61.1%.

[0070] Example 8

[0071] The method for synthesizing a large amount of diarylmethane compounds described in this Example 8 consists of the following steps:

[0072] (1) Take a 250 mL single-necked flask, add a magnetic stir bar, and add 4-biphenylmethanol (1.84 g, 0.01 mol) and ethylbenzene (4.25 g, 0.04 mol) thereto. Then add 100 mL of high-fluorotert-butanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add trifluoroacetic acid catalyst (0.23 g, 0.002 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 60 °C under stirring, react for 12 hours, and then stop the reaction. Filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product;

[0073] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography. Spot the plate to judge the separation to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum to obtain 1.85 g of diarylmethane compound with a yield of 68.0%.

[0074] Example 9

[0075] The method for synthesizing a large amount of diarylmethane compounds described in this Example 9 consists of the following steps:

[0076] (1) Take a 100 mL single-necked flask, add a magnetic stir bar, and add 3-furanmethanol (0.98 g, 0.01 mol) and ethylbenzene (4.25 g, 0.04 mol) thereto. Then add 50 mL of high-fluorotert-butanol solvent, turn on the magnetic stirrer to disperse the raw materials evenly in the solvent. While stirring, add trifluoroacetic acid catalyst (0.12 g, 0.001 mol) to the reaction system to make the catalyst disperse evenly. Subsequently, connect a condenser (apply vacuum grease at the interface and clamp it with a plastic clip), turn on the cooling water, heat the reaction system to 50 °C under stirring, react for 20 hours, and then stop the reaction. Filter the above-obtained original reaction solution by suction, transfer the filtrate to a round-bottom flask, and rotary evaporate the solvent and excess ethylbenzene in the filtrate to obtain the corresponding crude product.

[0077] (2) Subject the concentrated crude product obtained above to wet column loading and separate and purify it by silica gel column chromatography. Spot the plate to judge the separation to obtain a pure product solution, then rotary evaporate to obtain the pure product, and further dry it under vacuum to obtain 1.32 g of a diarylmethane compound with a yield of 70.9%.

[0078] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the present invention. The above embodiments are only used to explain the present invention, rather than to limit the present invention. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for synthesizing a large amount of diarylmethane compounds, characterized in that: It consists of the following steps: (1) firstly placing a phenyl alcohol reactant and an aromatic hydrocarbon reactant in an organic solvent, then adding a catalyst to react under stirring, and after the reaction is completed, removing the organic solvent and the remaining aromatic hydrocarbon reactant by rotary evaporation to obtain a crude product; (2) subjecting the crude product obtained in step (1) to separation and purification by silica gel column chromatography to obtain diarylmethane compounds; in: The general structural formula of the diarylmethane compound prepared in step (2) is shown in formula (I): In the formula (I), R1 and R3 are selected from any one of the following chemical structural formulas 1-10; R2 is selected from any one of the following chemical structural formulas 11; wherein i and j are integers of 2-20, k is an integer of 0-20; X is selected from one of Br element, nitrile group or amino group; Y1 and Y2 are selected from one of F element, Cl element, Br element, I element, nitrile group or phenyl group; Z is selected from one of O or S element; * indicates the substitution position; The organic solvent described in step (1) is one or more of high-fluorinated tert-butyl alcohol, hexafluoro-2,3-bis(trifluoromethyl)-2,3-diol, 2,2,2-trifluoroethanol, 1-phenyl-2,2,2-trifluoroethanol, 2,6-difluorobenzaldehyde, 2-perfluorooctylethanol or perfluorohexylethyl alcohol; The catalyst described in step (1) is one or more of trifluoroacetic acid, trifluoroacetic anhydride or fluorinated phosphoric acid.

2. The method for synthesizing a large amount of diarylmethane compounds according to claim 1, characterized in that: The general structural formula of the phenyl alcohol reactant in step (1) is shown in formula (II): The general structural formula of the aromatic hydrocarbon reactant in step (1) is shown in formula (III): R3-H (III); R1, R2 and R3 are the same as R1, R2 and R3 in the general structural formula of diarylmethane compounds.

3. The method for synthesizing a large amount of diarylmethane compounds according to claim 1, characterized in that: The organic solvent described in step (1) is high-fluorinated tert-butyl alcohol; the catalyst described in step (1) is trifluoroacetic acid.

4. The method for synthesizing a large amount of diarylmethane compounds according to claim 1, characterized in that: The concentration of the phenyl alcohol reactant in the organic solvent in step (1) is 0.1-8 mol / L; the molar ratio of the phenyl alcohol reactant to the aromatic hydrocarbon reactant in step (1) is 1:1.1-10.

5. The method for synthesizing a large amount of diarylmethane compounds according to claim 4, characterized in that: In step (1), the concentration of the phenyl alcohol reactant in the organic solvent is 0.4-5 mol / L; and the molar ratio of the phenyl alcohol reactant to the aromatic hydrocarbon reactant in step (1) is 1:1.5-6.

6. The method for synthesizing a large amount of diarylmethane compounds according to claim 1, characterized in that: The amount of the catalyst used in step (1) is 2-60 mol% of the phenyl alcohol reactant.

7. The method for synthesizing a large amount of diarylmethane compounds according to claim 6, characterized in that: The amount of the catalyst used in step (1) is 5-20 mol% of the phenyl alcohol reactant.

8. The method for synthesizing a large amount of diarylmethane compounds according to claim 1, characterized in that: In step (1), the reaction temperature is 5-150° C. and the reaction time is 0.2-72 h.

9. The method for synthesizing a large amount of diarylmethane compounds according to claim 8, characterized in that: In step (1), the reaction temperature is 20-100° C. and the reaction time is 0.5-24 h.

10. An application of the diarylmethane compound synthesized by the above method as claimed in claim 1, characterized in that: Diarylmethane compounds are used as high and low temperature lubricating materials in the field of organic heat carriers.

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