Preparation method of 2, 3-dimethyl-2, 3-diphenyl butane

Abstract

The invention discloses a preparation method of 2, 3-dimethyl-2, 3-diphenyl butane, and relates to the technical field of chemical synthesis.The scheme includes the following steps that S1, raw materials are prepared, specifically, 400 g of di-tert-butyl peroxide, 800 g of cumene and 2 g of a catalyst are weighed; s2, putting the raw materials in the S1 into a reaction kettle, stirring, heating, and reacting at normal pressure; s3, carrying out solid-liquid separation on the solution obtained in S2, and continuously applying the solid; s4, concentrating the liquid separated in S3 until no liquid flows out, cooling, carrying out suction filtration to obtain 2, 3-dimethyl-2, 3-diphenyl butane, and drying the 2, 3-dimethyl-2, 3-diphenyl butane; and S5, carrying out normal-pressure separation on the concentrated mother liquor in the step S4 to obtain a low boiling point, wherein the mother liquor is not evaporated out for later use. The method is high in yield, low in reaction temperature, short in reaction time, recyclable in raw materials, free of wastewater discharge, energy-saving and environment-friendly, and ruthenium is used as the catalyst, so that the original catalytic selectivity of a homogeneous phase is kept, the reaction rate is increased, and meanwhile, the effect of controlling the reaction speed by adjusting the temperature can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a method for preparing 2,3-dimethyl-2,3-diphenylbutane. Background Art

[0002] 2,3-Dimethyl-2,3-diphenylbutane, also known as 2-hydroxy-2-nitro-2-ol, is a carbon-based free radical initiator with a special structure. The CC bond between the corresponding quaternary carbon atoms is unstable and easily dissociates to form free radicals. This product is a new type of polymer material additive and can be used as a flame retardant synergist for polymer materials and a catalyst or initiator for polymer cross-linking and graft copolymerization. It is widely used in the modification of various polymer materials such as polyolefins, polyacrylates, polycarbonates, and polyethers. Because this initiator does not contain oxygen, the processed polymer has strong anti-aging and antioxidant capabilities. Compared with general free radical initiators such as peroxides and azo compounds, it has high stability and is safe to use.

[0003] The existing methods for preparing 2,3-dimethyl-2,3-diphenylbutane include using di-tert-butyl peroxide as an initiator, which requires a long reaction time and a high reaction temperature. Another method is using azo as an initiator and adding a catalyst for preparation, which is a complicated process and has a high cost and is not easy to be industrialized. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for preparing 2,3-dimethyl-2,3-diphenylbutane, which solves the problems raised in the background technology.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a method for preparing 2,3-dimethyl-2,3-diphenylbutane, comprising the following steps: S1. Raw material preparation: weigh 400 g of di-tert-butyl peroxide, 800 g of cumene, and 2 g of ruthenium catalyst; S2, stirring reaction, putting the raw materials in S1 into the reactor, stirring and heating, and reacting at normal pressure; S3, solid-liquid separation, the solution obtained in S2 is subjected to solid-liquid separation, and the solid is continuously applied; S4, concentrating and filtering, concentrating the liquid separated in S3 until no liquid flows out, cooling and filtering to obtain 2,3-dimethyl-2,3-diphenylbutane, and drying; S5, the mother liquor is evaporated and separated, and the concentrated mother liquor in S4 is separated at low boiling point under normal pressure, and the mother liquor is not evaporated and reused.

[0006] Preferably, in step S2, the temperature is raised to 80° C. with stirring, and the reaction time is 12 hours at normal pressure.

[0007] Preferably, in step S4, about 250 g of 2,3-dimethyl-2,3-diphenylbutane is obtained by suction filtration and about 200 g is obtained by drying.

[0008] Preferably, the preparation method of the ruthenium catalyst comprises the following steps: a. Activation of attapulgite: 50g of attapulgite is calcined in a muffle furnace and cooled to room temperature. It is placed in a three-necked flask, 100mL of 1mol / L hydrochloric acid is added to the flask, and stirred at a constant temperature of 90°C for 4h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until no Cl ions are detected in the filtrate with a 0.01mol / LAgNO3 solution. The precipitate is placed in a beaker, 100mL of 10% oxalic acid solution is added thereto, stirred at room temperature for 2h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until the washing liquid is neutral. The precipitate is taken out and dried at 120°C to obtain activated attapulgite, which is ground into powder and passed through a 200-mesh sieve for standby use; b. Preparation of chitosan-loaded attapulgite: slowly add 1g chitosan to a mixture of 20mL of 10% oxalic acid and 5mL of 1% acetic acid, and stir at 50°C to completely dissolve the chitosan into a sol. Take 10mL of this chitosan sol, add 20mL of deionized water to it, stir at 50°C for 1h, slowly add 5g of activated attapulgite, stir for 5h, filter, and dry the filtered precipitate to constant weight under vacuum at 55°C. Slowly add the dried chitosan-loaded activated attapulgite to 10mL of chitosan sol, stir at 50°C for 6h, and let stand for 6h. Filter off the supernatant, transfer the precipitate to 20mL of 1.0mol / L NaOH solution, and stir for 1h. Wash with deionized water until the filtrate is neutral, filter by suction, dry the filtered precipitate at 55°C under vacuum for 24 hours to obtain chitosan-loaded attapulgite, grind it into powder, pass it through a 200-mesh sieve, and set aside; c. Preparation of ruthenium-loaded chitosan attapulgite. Weigh 1.2 g of chitosan attapulgite and add it to an aqueous solution of RuCl3 (0.913 g, 4.4 mmol). Stir the mixed solution in an oil bath at a constant temperature for 12 h, then remove moisture by rotary evaporation and dry. Grind the obtained solid and put it into a tubular furnace. In a nitrogen atmosphere, heat it to 900 °C at a rate of 3 °C / min and calcine it at a constant temperature for 1 h. Add the obtained black solid to 60 ml of 1 M hydrochloric acid, stir it in an oil bath at a constant temperature, reflux it for 12 h, filter it, wash it with water to obtain a solid, and dry it to obtain the catalyst Ru.

[0009] Preferably, in step a, the calcination temperature is 700° C. and the calcination time is 3 h.

[0010] Preferably, in step c, the temperature of the first oil bath is 80°C, and the temperature of the second oil bath is 120°C.

[0011] The present invention provides a method for preparing 2,3-dimethyl-2,3-diphenylbutane, which has the following beneficial effects: The method for preparing 2,3-dimethyl-2,3-diphenylbutane has high yield, low reaction temperature, short reaction time, recyclable raw materials, no wastewater discharge, energy saving and environmental protection, and the use of ruthenium as a catalyst not only maintains the original catalytic selectivity of the homogeneous phase, but also accelerates the reaction rate, and can also achieve the effect of controlling the reaction speed by adjusting the temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a flow chart for preparing 2,3-dimethyl-2,3-diphenylbutane; Figure 2 The present invention is a flow chart for preparing the ruthenium catalyst; DETAILED DESCRIPTION

[0013] 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. Embodiment 1:

[0014] like Figure 1 As shown, a method for preparing 2,3-dimethyl-2,3-diphenylbutane comprises the following steps: S1. Raw material preparation: weigh 400 g of di-tert-butyl peroxide, 800 g of cumene, and 2 g of ruthenium catalyst; S2, stirring reaction, putting the raw materials in S1 into the reactor, stirring and heating, and reacting at normal pressure; S3, solid-liquid separation, the solution obtained in S2 is subjected to solid-liquid separation, and the solid is continuously applied; S4, concentrating and filtering, concentrating the liquid separated in S3 until no liquid flows out, cooling and filtering to obtain 2,3-dimethyl-2,3-diphenylbutane, and drying; S5, the mother liquor is evaporated and separated, and the concentrated mother liquor in S4 is separated at low boiling point under normal pressure, and the mother liquor is not evaporated and reused.

[0015] In step S2, the temperature is raised to 80° C. with stirring, and the reaction time is 12 hours under normal pressure.

[0016] In step S4, about 250 g of 2,3-dimethyl-2,3-diphenylbutane is obtained by suction filtration and about 200 g is obtained by drying. Embodiment 2:

[0017] like Figure 2As shown, a method for preparing a ruthenium catalyst comprises the following steps: a. Activation of attapulgite: 50g of attapulgite is calcined in a muffle furnace and cooled to room temperature. It is placed in a three-necked flask, 100mL of 1mol / L hydrochloric acid is added to the flask, and stirred at a constant temperature of 90°C for 4h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until no Cl ions are detected in the filtrate with a 0.01mol / LAgNO3 solution. The precipitate is placed in a beaker, 100mL of 10% oxalic acid solution is added thereto, stirred at room temperature for 2h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until the washing liquid is neutral. The precipitate is taken out and dried at 120°C to obtain activated attapulgite, which is ground into powder and passed through a 200-mesh sieve for standby use; b. Preparation of chitosan-loaded attapulgite: slowly add 1g chitosan to a mixture of 20mL of 10% oxalic acid and 5mL of 1% acetic acid, and stir at 50°C to completely dissolve the chitosan into a sol. Take 10mL of this chitosan sol, add 20mL of deionized water to it, stir at 50°C for 1h, slowly add 5g of activated attapulgite, stir for 5h, filter, and dry the filtered precipitate to constant weight under vacuum at 55°C. Slowly add the dried chitosan-loaded activated attapulgite to 10mL of chitosan sol, stir at 50°C for 6h, and let stand for 6h. Filter off the supernatant, transfer the precipitate to 20mL of 1.0mol / L NaOH solution, and stir for 1h. Wash with deionized water until the filtrate is neutral, filter by suction, dry the filtered precipitate at 55°C under vacuum for 24 hours to obtain chitosan-loaded attapulgite, grind it into powder, pass it through a 200-mesh sieve, and set aside; c. Preparation of ruthenium-loaded chitosan attapulgite. Weigh 1.2 g of chitosan attapulgite and add it to an aqueous solution of RuCl3 (0.913 g, 4.4 mmol). Stir the mixed solution in an oil bath at a constant temperature for 12 h, then remove moisture by rotary evaporation and dry. Grind the obtained solid and put it into a tubular furnace. In a nitrogen atmosphere, heat it to 900 °C at a rate of 3 °C / min and calcine it at a constant temperature for 1 h. Add the obtained black solid to 60 ml of 1 M hydrochloric acid, stir it in an oil bath at a constant temperature, reflux it for 12 h, filter it, wash it with water to obtain a solid, and dry it to obtain the catalyst Ru.

[0018] In step a, the calcination temperature is 700° C. and the calcination time is 3 h.

[0019] In step c, the first oil bath temperature is 80°C, and the second oil bath temperature is 120°C.

[0020] Since inorganic supports are not easy to contact with organic reactants and supported catalysts, and supported catalysts on organic supports are easily soluble in organic solvents and often affect the catalytic activity and catalytic selectivity of the catalyst, supported catalysts on organic-inorganic hybrid supports came into being. This type of support effectively combines the advantages of inorganic supports and organic supports, while also solving their respective shortcomings.

[0021] Experimental results have shown that this catalyst not only maintains the original catalytic selectivity of the homogeneous phase, but also accelerates the reaction rate, while also being able to achieve the effect of controlling the speed of the reaction by adjusting the temperature.

[0022] Working principle: 400g of di-tert-butyl peroxide, 800g of isopropylbenzene, 2g of catalyst, stir and heat to 80℃, react for 12 hours at normal pressure, filter after the reaction, separate the solid and liquid, continue to apply the solid, concentrate the liquid until no liquid flows out, cool and filter to obtain about 250g of 2,3-dimethyl-2,3-diphenylbutane, dry about 200g, separate the mother liquor at normal pressure to reduce the low boiling point, apply the mother liquor that is not evaporated, 2g of catalyst, repeat this cycle, the second batch output becomes 275g, and the yield reaches about 84.35%.

[0023] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0024] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing 2,3-dimethyl-2,3-diphenylbutane, characterized in that: The following steps are involved: S1. Raw material preparation: weigh 400 g of di-tert-butyl peroxide, 800 g of cumene, and 2 g of ruthenium catalyst; S2, stirring reaction, putting the raw materials in S1 into the reactor, stirring and heating, and reacting at normal pressure; S3, solid-liquid separation, the solution obtained in S2 is subjected to solid-liquid separation, and the solid is continuously applied; S4, concentrating and filtering, concentrating the liquid separated in S3 until no liquid flows out, cooling and filtering to obtain 2,3-dimethyl-2,3-diphenylbutane, and drying; S5, the mother liquor is evaporated and separated, and the concentrated mother liquor in S4 is separated at low boiling point under normal pressure, and the mother liquor is not evaporated and reused.

2. A method for preparing 2,3-dimethyl-2,3-diphenylbutane according to claim 1, characterized in that: In step S2, the temperature is raised to 80° C. with stirring, and the reaction time is 12 hours under normal pressure.

3. A method for preparing 2,3-dimethyl-2,3-diphenylbutane according to claim 1, characterized in that: In step S4, about 250 g of 2,3-dimethyl-2,3-diphenylbutane is obtained by suction filtration and about 200 g is obtained by drying.

4. A method for preparing 2,3-dimethyl-2,3-diphenylbutane according to claim 1, characterized in that: The preparation method of the catalyst ruthenium comprises the following steps: a. Activation of attapulgite: 50g of attapulgite is calcined in a muffle furnace and cooled to room temperature. It is placed in a three-necked flask, 100mL of 1mol / L hydrochloric acid is added to the flask, and stirred at a constant temperature of 90°C for 4h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until no Cl ions are detected in the filtrate with a 0.01mol / LAgNO3 solution. The precipitate is placed in a beaker, 100mL of 10% oxalic acid solution is added thereto, stirred at room temperature for 2h, allowed to stand, the acid solution is filtered out, and the precipitate is washed with deionized water until the washing liquid is neutral. The precipitate is taken out and dried at 120°C to obtain activated attapulgite, which is ground into powder and passed through a 200-mesh sieve for standby use; b. Preparation of chitosan-loaded attapulgite: slowly add 1g chitosan to a mixture of 20mL of 10% oxalic acid and 5mL of 1% acetic acid, and stir at 50°C to completely dissolve the chitosan into a sol. Take 10mL of this chitosan sol, add 20mL of deionized water to it, stir at 50°C for 1h, slowly add 5g of activated attapulgite, stir for 5h, filter, and dry the filtered precipitate to constant weight under vacuum at 55°C. Slowly add the dried chitosan-loaded activated attapulgite to 10mL of chitosan sol, stir at 50°C for 6h, and let stand for 6h. Filter off the supernatant, transfer the precipitate to 20mL of 1.0mol / L NaOH solution, and stir for 1h. Wash with deionized water until the filtrate is neutral, filter by suction, dry the filtered precipitate at 55°C under vacuum for 24 hours to obtain chitosan-loaded attapulgite, grind it into powder, pass it through a 200-mesh sieve, and set aside; c. Preparation of ruthenium-loaded chitosan attapulgite. Weigh 1.2 g of chitosan attapulgite and add it to an aqueous solution of RuCl3 (0.913 g, 4.4 mmol). Stir the mixed solution in an oil bath at a constant temperature for 12 h, then remove moisture by rotary evaporation and dry. Grind the obtained solid and put it into a tubular furnace. In a nitrogen atmosphere, heat it to 900 °C at a rate of 3 °C / min and calcine it at a constant temperature for 1 h. Add the obtained black solid to 60 ml of 1 M hydrochloric acid, stir it in an oil bath at a constant temperature, reflux it for 12 h, filter it, wash it with water to obtain a solid, and dry it to obtain the catalyst Ru.

5. A method for preparing 2,3-dimethyl-2,3-diphenylbutane according to claim 4, characterized in that: In step a, the calcination temperature is 700° C. and the calcination time is 3 h.

6. A method for preparing 2,3-dimethyl-2,3-diphenylbutane according to claim 4, characterized in that: In step c, the first oil bath temperature is 80°C, and the second oil bath temperature is 120°C.

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