CN111393304A - Method for preparing p-phenylenediamine from aniline - Google Patents
Method for preparing p-phenylenediamine from aniline Download PDFInfo
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- CN111393304A CN111393304A CN202010072429.7A CN202010072429A CN111393304A CN 111393304 A CN111393304 A CN 111393304A CN 202010072429 A CN202010072429 A CN 202010072429A CN 111393304 A CN111393304 A CN 111393304A
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- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/62—Preparation of compounds containing amino groups bound to a carbon skeleton by cleaving carbon-to-nitrogen, sulfur-to-nitrogen, or phosphorus-to-nitrogen bonds, e.g. hydrolysis of amides, N-dealkylation of amines or quaternary ammonium compounds
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- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/36—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids
- C07C303/38—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids by reaction of ammonia or amines with sulfonic acids, or with esters, anhydrides, or halides thereof
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- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/36—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids
- C07C303/40—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids by reactions not involving the formation of sulfonamide groups
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Abstract
The invention provides a method for preparing p-phenylenediamine from aniline. The method comprises the following steps: protecting amino on aniline with p-toluenesulfonyl, mixing with amino donor, oxidant and catalyst Ru-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain p-phenylenediamine. The invention adopts a protecting group strategy to protect amino on aniline by p-toluenesulfonyl, simultaneously induces and activates C-H bond of para-benzene ring, adopts catalyst Ru-Cu/TS-1 to catalyze ammoniation reaction, can greatly improve ammoniation efficiency and selectivity, improves the yield and purity of p-phenylenediamine, has mild reaction conditions and good selectivity, and is a green and environment-friendly synthetic route.
Description
Technical Field
The invention belongs to the technical field of fine chemical engineering, relates to a synthetic method of p-phenylenediamine, and particularly relates to a method for preparing p-phenylenediamine from aniline.
Background
p-Phenylenediamine, also known as "Ulex D", is one of the simplest aromatic diamines, and is also an organic intermediate with wide application, and can be used to prepare azo dyes, high molecular polymers, and reagents for producing fur coloring agents, rubber antioxidants, and photo developers. Aramid 1414 obtained by condensation polymerization of p-phenylenediamine and terephthaloyl chloride in the defense industry belongs to high-temperature-resistant high-molecular liquid crystal resin and can be used in composite materials of supersonic aircrafts. In addition, p-phenylenediamine is also a main raw material of a gasoline polymerization inhibitor, the annual demand of the current Chinese p-phenylenediamine is about 2 ten thousand tons, wherein 60 percent of the p-phenylenediamine is used for synthesizing dyes, 25 percent of the p-phenylenediamine is used for synthesizing rubber auxiliaries, and 15 percent of the p-phenylenediamine is used in other fields. With the increasing production of the global aramid 1414 in the coming years, the annual demand of p-phenylenediamine will increase at a high rate.
Currently, there are two main commercial routes for p-phenylenediamine synthesis:
route one: p-chloronitrobenzene process. CN109651158A discloses a method for preparing p-phenylenediamine, wherein the p-phenylenediamine is prepared by reducing nitroaniline with hydrogen under the condition of a catalyst, the method uses water as a solvent and hydrogen as a reducing agent to catalyze and reduce nitro group to prepare p-phenylenediamine, and the preparation process can be represented by the following reaction formula:
the preparation method realizes the control of the conversion rate of the p-phenylenediamine by controlling the temperature, the pressure and the reaction time in the reduction reaction. The invention utilizes the production mode of hydrogenation reduction to improve the conversion rate of the paranitroaniline and obtain the high-purity p-phenylenediamine.
CN107619374A discloses a new process for producing p-phenylenediamine by a continuous method, which comprises the steps of taking p-nitroaniline, a solvent and hydrogen as main raw materials, preparing a p-phenylenediamine crude product by hydrogenation reaction in a fixed bed reactor or a tubular reactor in the presence of a catalyst, preparing the p-phenylenediamine with high purity from the crude product by a rectification recovery process, and separating and rectifying the product to obtain the p-phenylenediamine with the purity of 99.9%.
The p-chloronitrobenzene method is a common method for industrial production, the raw material p-nitroaniline is obtained by nitration and ammonolysis of chlorobenzene, the energy consumption is high, equipment is corroded, and a large amount of acid sludge, NO and NO are generated2And the like, and phenol-containing wastewater.
And a second route: ammoniation method of p-dichlorobenzene. US1994845 discloses a method for preparing p-phenylenediamine by catalytic ammonolysis of p-dichlorobenzene using cuprous oxide as a catalyst, 28 wt% ammonia water as an ammonia source, reacting at 150-:
US4193938 discloses a method for preparing p-phenylenediamine by catalytic ammonolysis of p-dichlorobenzene, which takes cuprous chloride as a catalyst and reacts for 12 hours at the reaction temperature of 200 ℃ and 220 ℃ to obtain the p-phenylenediamine with the yield of 91%. However, the reaction temperature in the route is higher, and the energy consumption is larger.
Therefore, the method develops a synthetic route for preparing p-phenylenediamine by directly ammoniating aniline under normal pressure, and has great scientific research value and application prospect.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide a method for preparing p-phenylenediamine from aniline. The synthetic route provided by the invention is simple, the reaction condition is mild, the reaction process is safe, and the yield and the purity of the product p-phenylenediamine are high.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for preparing p-phenylenediamine from aniline, which comprises the following steps: protecting amino on aniline with p-toluenesulfonyl, mixing with amino donor, oxidant and catalyst Ru-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain p-phenylenediamine.
The reaction process can be represented by the following reaction equation:
in the invention, TS-1 is a titanium-silicon molecular sieve, has both catalytic oxidation activity and shape-selective catalytic performance, and has unique catalytic performance for shape-selective oxidation reactions of various organic compounds with oxidant. Ruthenium metal (Ru) and copper metal (Cu) are combined on the TS-1 to be used as a catalyst Ru-Cu/TS-1, and the reaction efficiency and selectivity can be greatly improved.
According to the invention, a protecting group strategy is adopted to protect amino on aniline by p-toluenesulfonyl, C-H bonds in the para position of a benzene ring are induced and activated at the same time, a catalyst Ru-Cu/TS-1 is adopted to catalyze ammoniation reaction, and an oxidant is combined with hydrogen falling in the reaction process to promote the forward process of the reaction, so that the ammoniation efficiency and selectivity can be greatly improved, the reaction condition is mild, the selectivity is good, and the method is a green and environment-friendly synthetic route.
Preferably, the method comprises the steps of:
(1) mixing p-toluenesulfonyl chloride, an acid-binding agent (acid Reagent), a solvent and the aniline and then reacting to obtain p-toluenesulfonyl aniline;
(2) mixing the p-toluenesulfonanilide, an amino donor, a catalyst Ru-Cu/TS-1 and a solvent, and then adding the oxidant for reaction to obtain p-aminobenzenesulfonanilide;
(3) and deprotecting the p-aminobenzene sulfonanilide, and separating to obtain the p-phenylenediamine.
As a preferred embodiment of the present invention, the molar ratio of tosyl chloride to aniline in the process is (1-1.2):1, and may be, for example, 1:1, 1.05:1, 1.08:1, 1.1:1, 1.15:1, 1.16:1, 1.18:1 or 1.2: 1.
In the invention, the content of the p-toluenesulfonyl chloride is slightly higher than that of aniline so as to completely protect amino, but if the content of the p-toluenesulfonyl chloride is higher, substitution can be caused at other positions of a benzene ring.
In a preferred embodiment of the present invention, the molar ratio of aniline to oxidant in the process is 1 (1-5), and may be, for example, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1: 5.
Preferably, the molar ratio of aniline to ammonia in the process is 1 (1-10), and may be, for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, etc.
Preferably, the mass ratio of the catalyst Ru-Cu/TS-1 to the aniline in the method is 1 (5-100), and can be 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90 or 1:100, and the like.
As a preferred technical scheme of the invention, the reaction in the step (1) is carried out under a nitrogen protective atmosphere.
Preferably, the reaction temperature in step (1) is 50-80 ℃, for example, 50 ℃, 55 ℃, 58 ℃, 60 ℃, 65 ℃, 66 ℃, 70 ℃, 72 ℃, 75 ℃, 78 ℃ or 80 ℃.
Preferably, the acid-binding agent in step (1) comprises one or more of triethylamine, pyridine, piperidine, piperazine, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, potassium phosphate and potassium acetate.
Preferably, the solvent in step (1) comprises any one or a combination of two or more of dichloromethane, tetrahydrofuran, petroleum ether or n-hexane.
In a preferred embodiment of the present invention, the oxidizing agent in step (2) comprises any one or a combination of two or more of hydrogen peroxide, p-benzoquinone, t-butyl peroxide, and potassium persulfate.
Preferably, the amino donor of step (2) comprises ammonia or liquid ammonia.
Preferably, the mass concentration of the ammonia water is 20% to 30%, and may be, for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or the like.
Preferably, the solvent in step (2) comprises any one or a combination of two or more of acetone, methanol, ethanol, isopropanol, N '-dimethylformamide, N' -dimethylacetamide, or dimethylsulfoxide.
Preferably, the reaction time in step (2) is 3 to 5h, and may be, for example, 3h, 3.2h, 3.5h, 3.8h, 4h, 4.2h, 4.5h, 4.8h, 5h, or the like.
Preferably, the reaction temperature in step (2) is 50 to 150 ℃, and may be, for example, 50 ℃, 55 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃ or 150 ℃, etc.
Preferably, the catalyst Ru-Cu/TS-1 in the step (2) is prepared by using an isometric impregnation method.
Preferably, the preparation method of the catalyst Ru-Cu/TS-1 comprises the following steps:
and dipping the ruthenium salt solution and the copper salt solution into the TS-1 molecular sieve solution, adding alkali to adjust the pH value so as to completely precipitate ruthenium metal and copper metal in the solution, washing, drying and then reducing by hydrogen to obtain the catalyst Ru-Cu/TS-1.
Preferably, the specific surface area of the TS-1 molecular sieve is 300-2G, may be, for example, 300m2/g、320m2/g、350m2/g、380m2/g、400m2/g、420m2/g、450m2/g、480m2G or 500m2And the like, and the bulk density thereof is 0.45 to 0.55g/m L, and may be, for example, 0.45g/m L, 0.46g/m L0, 0.47g/m L1, 0.48g/m L, 0.49g/m L, 0.50g/m L, 0.51g/m L, 0.52g/m L, 0.53g/m L, 0.54g/m L, 0.55g/m L, or the like.
Preferably, the TS-1 molecular sieve has a pore volume of 0.45-0.8m L/g, such as 0.45m L/g, 0.50m L/g, 0.55m L/g, 0.60m L/g, 0.65m L/g, 0.70m L/g, 0.75m L/g, 0.78m L/g, or 0.8m L/g, etc., and a catalytic water absorption of 0.1-0.3g/g, such as 0.1g/g, 0.12g/g, 0.15g/g, 0.18g/g, 0.2g/g, 0.22g/g, 0.25g/g, 0.28g/g, or 0.3g/g, etc.
Preferably, the Ru loading of the catalyst Ru-Cu/TS-1 is 0.5-2%, and can be, for example, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.6%, 1.8%, 2%, or the like.
Preferably, the amount of Cu supported in the catalyst Ru-Cu/TS-1 is 0.5-2%, and may be, for example, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.6%, 1.8%, 2%, or the like.
As a preferable technical scheme of the invention, the ruthenium salt comprises any one or the combination of more than two of ruthenium trichloride, ruthenium acetate, ruthenium acetylacetonate or ruthenium nitrosyl nitrate.
Preferably, the copper salt comprises any one or a combination of two or more of copper sulfate, copper nitrate, copper chloride or copper acetate.
Preferably, the base comprises any one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate.
Preferably, the base is added to adjust the solution pH to 9-12, which may be, for example, 9, 9.2, 9.5, 9.8, 10, 10.2, 10.5, 11, 11.2, 11.5, 11.8, or 12, and the like.
Preferably, the hydrogen reduction operation is performed in a tubular furnace, and the reduction temperature is 350-450 ℃, such as 350 ℃, 355 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃ or 450 ℃.
In a preferred embodiment of the present invention, the deprotection composition used in the deprotection step (3) is selected from any one or a combination of two or more of magnesium/methanol (indicating that methanol and Mg are used simultaneously), hydrogen bromide/phenol, hydrogen fluoride/acetonitrile, lithium/liquid ammonia, and calcium fluoride/diatomaceous earth, and preferably calcium fluoride/diatomaceous earth.
Preferably, the separation in step (3) comprises any one or more of desalting, desolventizing or rectifying.
As a preferred technical scheme of the invention, the method comprises the following steps:
(1) mixing p-toluenesulfonyl chloride, an acid-binding agent, a solvent and the aniline, wherein the molar ratio of the p-toluenesulfonyl chloride to the aniline is (1-1.2):1, reacting at the temperature of 50-80 ℃ under the protection of nitrogen, and carrying out rotary evaporation to obtain p-toluenesulfonyl aniline;
(2) preparing a catalyst Ru-Cu/TS-1 by using an isometric impregnation method, wherein the metal load in the catalyst Ru-Cu/TS-1 is 1-5%, mixing the p-toluenesulfonanilide, ammonia water, the catalyst Ru-Cu/TS-1 and a solvent, wherein the molar ratio of the aniline to the ammonia water is 1 (1-10), the mass ratio of the catalyst Ru-Cu/TS-1 to the aniline is 1 (5-100), adding hydrogen peroxide, wherein the molar ratio of the aniline to the hydrogen peroxide is 1 (1-5), and reacting at 50-150 ℃ for 3-5h to obtain p-aminobenzene sulfonanilide;
(3) and under the protection of inert gas, carrying out deprotection, desalting, desolventizing and rectification on the p-aminobenzenesulfonylaniline by using a deprotection composition to obtain the p-phenylenediamine.
The recitation of numerical ranges herein includes not only the above-recited numerical values, but also any numerical values between non-recited numerical ranges, and is not intended to be exhaustive or to limit the invention to the precise numerical values encompassed within the range for brevity and clarity.
Compared with the prior art, the invention has the beneficial effects that:
(1) according to the synthetic route of p-phenylenediamine provided by the invention, aniline is used as a preparation raw material, p-toluenesulfonyl is adopted to protect amino, Ru-Cu/TS-1 is used as a catalyst, and amino is introduced to the para position of aniline to obtain p-phenylenediamine;
(2) the synthetic route provided by the invention has higher yield, the yield of the product p-phenylenediamine is more than 50%, the purity of the product can be effectively improved, and the purity of the p-phenylenediamine prepared by the method is more than 99.9%.
Drawings
FIG. 1 is a gas chromatogram of the product prepared in example 1.
Detailed Description
The technical solutions of the present invention are further described in the following embodiments with reference to the drawings, but the following examples are only simple examples of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.
In the following examples, the TS-1 molecular sieve was prepared as follows:
mixing 22.5g tetraethyl orthosilicate (TEOS), 7.0g tetrapropylammonium hydroxide (TPAOH) and 1g gamma-glycidoxypropyltrimethoxysilane, adding 59.8g of distilled water, stirring and mixing uniformly, and hydrolyzing at the conditions of normal pressure and 60 ℃ for 1h to obtain TEOS prehydrolysis liquid;
a solution of 1.1g tetrabutyl titanate (TBOT) and 5.0g absolute ethanol was added with vigorous stirring, and the resulting mixture was stirred at 75 ℃ for 3h to give a clear and transparent colloid. Putting the colloid into a hydrothermal reaction kettle, and carrying out hydrothermal reaction for 6 days at the temperature of 170 ℃ to obtain a crystallized mixed solution; and centrifuging, filtering and washing the mixed solution until the pH value is 6-8, drying the mixed solution for 2 hours at the temperature of 110 ℃, and roasting the dried mixed solution for 4 hours at the temperature of 550 ℃ in an air atmosphere to obtain the TS-1 molecular sieve.
Finally prepared TS-1 moleculeThe sieve is used as a catalyst carrier and has a diameter of 1mm and a specific surface area of 350m2The specific weight ratio of the catalyst to the water is 0.45-0.55g/m L, the pore volume is 0.45-0.8m L/g, and the catalytic water absorption capacity is 0.2 g/g.
In the following examples, TS-1 catalysts with varying Ru-Cu contents were prepared from both ruthenium and copper salts.
(1) Taking 0.5 percent Ru-0.5 percent Cu/TS-1 of catalyst prepared by ruthenium trichloride and copper nitrate as an example, the preparation method comprises the following steps:
weighing 1.02g of ruthenium trichloride and 1.48g of copper nitrate, dissolving the ruthenium trichloride and the copper nitrate in 20m L deionized water to form a mixed solution, soaking the mixed solution in 100g of TS-1 molecular sieve carrier in the same volume, transferring the mixed solution to an oven at 80 ℃ for drying for 12 hours, drying the molecular sieve carrier, cooling the molecular sieve carrier to room temperature, and adding a mixed alkali solution (the formula of the mixed alkali solution is NaOH and Na)2 CO 31% of total mass fraction of aqueous solution, NaOH and Na2CO3The mass ratio of 2:1) until the final system pH is 10 and the precipitation is complete, adding deionized water to wash until the conductivity is 50S/m, and drying in an oven at 110 ℃;
transferring the loaded TS-1 pellets into a tubular furnace, setting the hydrogen flow rate at 100m L/min, carrying out temperature programming at the speed of 5 ℃/min to 350 ℃, keeping the temperature at 350 ℃ for 2h to obtain 0.5 percent Ru-0.5 percent Cu/TS-1 catalyst, cooling the reduced catalyst to room temperature, introducing 0.5 percent diluted oxygen-nitrogen release mixed gas, and carrying out passivation treatment for 30min to obtain 101g of 0.5 percent Ru-0.5 percent Cu/TS-1 catalyst.
(2) Taking 0.5 percent Ru-1 percent Cu/TS-1 percent catalyst prepared from ruthenium nitrosyl nitrate and copper chloride as an example, the preparation method comprises the following steps:
weighing 1.56g of ruthenium nitrosyl nitrate and 5.4g of copper chloride, dissolving the mixed solution in 20m L deionized water to form a mixed solution, soaking the mixed solution in 100g of TS-1 molecular sieve carrier in the same volume, transferring the mixed solution to an oven at 80 ℃ for drying for 12h, drying the soaked molecular sieve carrier, cooling the dried molecular sieve carrier to room temperature, and adding mixed alkali liquor (the formula of the mixed alkali liquor is NaOH and Na)2 CO 31% of total mass fraction of aqueous solution, NaOH and Na2CO3The mass ratio of 2:1) until the final system pH is 10 and the precipitation is complete, adding deionized water to wash until the conductivity is 50S/m, and drying in an oven at 110 ℃;
transferring the loaded TS-1 pellets into a tubular furnace, setting the hydrogen flow rate at 100m L/min, carrying out temperature programming at the speed of 5 ℃/min to 350 ℃, keeping the temperature at 350 ℃ for 2h to obtain 0.5 percent Ru-1.0 percent Cu/TS-1 catalyst, cooling the reduced catalyst to room temperature, introducing 0.5 percent diluted oxygen-nitrogen release mixed gas, and carrying out passivation treatment for 30min to obtain 101.5g of 0.5 percent Ru-1.0 percent Cu/TS-1 catalyst.
In the following examples, the catalyst 1.0% Ru-1.0% Cu/TS-1 was prepared by a method similar to that for the catalyst 0.5% Ru-0.5% Cu/TS-1.
Example 1
This example provides a method for preparing p-phenylenediamine from aniline, comprising the following steps:
(1) adding a solvent 672g of dichloromethane (8.0mol), 46.5g of aniline (99.9%, 0.5mol) and 20g of acid-binding agent NaOH (0.5mol) into a flask, slowly dropwise adding 114.4g of p-toluenesulfonyl chloride (0.5mol) solution into the flask under the condition of stirring in an ice-water bath, tracking by T L C (thin layer chromatography) until the reaction is completed, filtering out insoluble sodium chloride, and removing the solvent dichloromethane by rotary evaporation to obtain p-toluenesulfonyl aniline crystals;
(2) p-toluenesulfonanilide, 580g of acetone (10.0mol), 212.5g of 20% ammonia (2.5mol), 190g of H2O2(1.5mol) and 4.65g of 0.5 percent Ru-0.5 percent Cu/TS-1 catalyst are added into a glass reactor, the reaction temperature is set to be 70 ℃, the reaction is finished after 4 hours of magnetic stirring, the catalyst is filtered and separated, and the solvent is removed by reduced pressure distillation to obtain a crude product;
(3) adding 500g of trifluoroethanol (5.0mol) and 50g of 1% calcium fluoride/kieselguhr (kieselguhr containing 1 wt% of calcium fluoride) into the crude product, refluxing in an argon atmosphere at 90 ℃, tracking by T L C until deprotection is complete, wherein the deprotection time is 2.5h, desalting, desolventizing and rectifying to obtain 29.7g of p-phenylenediamine, analyzing by using gas chromatography (Agilent 8890), detecting to obtain a gas chromatogram shown in figure 1, wherein the peak around 1.8min is a solvent peak, the peak-off time of the product is 10.145min, and is the same as that of a p-phenylenediamine standard product, so that the obtained product is p-phenylenediamine, and the purity of the product is 99.98%.
Example 2
This example provides a method for preparing p-phenylenediamine from aniline, comprising the following steps:
(1) adding a solvent 672g of dichloromethane (8.0mol), 46.5g of aniline (99.9%, 0.5mol) and 50g of acid-binding agent triethylamine (0.5mol) into a flask, slowly dropwise adding 114.4g of p-toluenesulfonyl chloride (0.5mol) solution into the flask under the condition of stirring in an ice-water bath, tracking T L C until the reaction is complete, washing with water to remove triethylamine hydrochloride, layering, and removing the solvent dichloromethane by rotary evaporation to obtain p-toluenesulfonanilide;
(2) p-toluenesulfonanilide, 480g methanol (15.0mol), 125g ammonia (1.25mol), 126.7g H were taken2O2(1.0mol) and 4.65g of 0.5 percent Ru-1.0 percent Cu/TS-1 catalyst are added into a glass reactor, the reaction temperature is set to be 70 ℃, the reaction is finished after 4 hours of magnetic stirring, the catalyst is filtered and separated, and the solvent is removed by reduced pressure distillation to obtain a crude product;
(3) 500g of trifluoroethanol (5.0mol) and 50g of 1% CaF were added to the crude product2Refluxing diatomite in an argon atmosphere at 90 ℃, tracking T L C until deprotection is complete, wherein the deprotection time is 3h, and obtaining 31.3g of p-phenylenediamine with the purity of 99.93 percent through desalting, desolventizing and rectifying.
Example 3
This example provides a method for preparing p-phenylenediamine from aniline, comprising the following steps:
(1) adding a solvent 672g of dichloromethane (8.0mol), 46.5g of aniline (99.9%, 0.5mol) and 42g of acid-binding agent sodium bicarbonate (0.5mol) into a flask, slowly dropwise adding 114.4g of p-toluenesulfonyl chloride (0.5mol) solution into the flask under the condition of stirring in an ice-water bath, tracking T L C until the reaction is completed, filtering out insoluble sodium chloride, and evaporating the solvent dichloromethane to obtain p-toluenesulfonyl aniline;
(2) taking p-toluenesulfonanilide, 460g ethanol (10.0mol), 125g ammonia water (1.25mol) and 190g H2O2(1.5mol) and 9.3g of 0.5 percent Ru-0.5 percent Cu/TS-1 catalyst are added into a glass reactor, the reaction temperature is set to 65 ℃, the reaction is finished after the magnetic stirring is kept for 4 hours, the catalyst is filtered and separated, and the solvent is removed by reduced pressure distillation to obtain a crude product;
(3) 500g of trifluoroethanol (5.0mol) and 50g of 1% CaF were added to the crude product2Diatomite at 90 ℃ under argon atmosphere, T L C until deprotection is complete, and the deprotection time is usedThe time is 4 hours, 34.6g of p-phenylenediamine is obtained through desalting, desolventizing and rectifying, and the purity is 99.97%.
Example 4
This example provides a method for preparing p-phenylenediamine from aniline, comprising the following steps:
(1) adding a solvent 576g of tetrahydrofuran (8.0mol), 46.5g of aniline (99.9%, 0.5mol) and 42g of acid-binding agent sodium bicarbonate (0.5mol) into a flask, slowly dropwise adding 114.4g of p-toluenesulfonyl chloride (0.5mol) solution into the flask under the condition of stirring in an ice-water bath, tracking by T L C until the reaction is complete, washing with water to remove salt, and removing the solvent tetrahydrofuran by rotary evaporation to obtain p-toluenesulfonanilide;
(2) p-toluenesulfonanilide, 600g of isopropanol (10.0mol), 250g of ammonia (17 wt%, 2.5mol), 190g of oxidizing agent H were taken2O2(1.5mol) and 4.65g of 1.0 percent Ru-1.0 percent Cu/TS-1 catalyst are added into a reactor, the reaction temperature is set to be 150 ℃, the reaction is finished after stirring for 3 hours, the catalyst is filtered and separated, and the solvent is removed by reduced pressure distillation to obtain a crude product;
(3) 1265g of 48% HBr (15mol) and 141g of phenol (1.5mol) are added into the crude product, the mixture is heated to 130 ℃ under the protection of argon atmosphere and refluxed for 8h, T L C is tracked until the deprotection is completed, and 28.11g of p-phenylenediamine with the purity of 99.95% is obtained through desalting, desolventizing and rectifying.
Example 5
This example provides a method for preparing p-phenylenediamine from aniline, comprising the following steps:
(1) adding a solvent of 576g of tetrahydrofuran (8.0mol), 46.5g of aniline (99.9%, 0.5mol) and 50g of acid-binding agent of triethylamine (0.5mol) into a flask, slowly dropwise adding 114.4g of p-toluenesulfonyl chloride (0.5mol) solution into the flask under the condition of stirring in an ice-water bath, reacting for 4 hours, tracking T L C until the reaction is complete, washing with water to remove salt, and evaporating the solvent of tetrahydrofuran to obtain p-toluenesulfonanilide;
(2) p-toluenesulfonanilide, 580g of acetone, 250g of ammonia (17 wt%, 2.5mol), 190g of oxidant H were taken2O2(1.5mol) and 9.3g of 1.0 percent Ru-1.0 percent Cu/TS-1 catalyst are added into a reactor, the reaction temperature is set to be 50 ℃, the reaction is finished after 5 hours of magnetic stirring, the catalyst is filtered and separated, and the pressure is reduced to steamDistilling to remove the solvent to obtain a crude product;
(3) 1265g of 48% HBr (15mol) and 141g of phenol (1.5mol) are added into the crude product in an argon atmosphere for protection, the mixture is heated to 130 ℃ for reflux and 8h for removing the protecting group, T L C is tracked until the deprotection is complete, and the product p-phenylenediamine 44.33g with the purity of 99.97% is obtained through desalination, desolventization and rectification.
Example 6
The same as example 1, a process for producing p-phenylenediamine from aniline was provided, except that in this example, ammonia water was replaced with 42.5g (2.5mol) of liquid ammonia, and the remaining conditions and production process were the same as in example 1, whereby 34.68g of p-phenylenediamine was obtained with a purity of 99.97%.
Example 7
The same as example 1, a process for producing p-phenylenediamine from aniline was provided, except that in this example, 135g (1.5mol) of t-butyl peroxide was used instead of hydrogen peroxide, and the remaining conditions and production process were the same as in example 1, whereby 23.71g of p-phenylenediamine was obtained as a product having a purity of 99.92%.
Example 8
In the same manner as in example 1, a process for producing p-phenylenediamine from aniline was provided, except that in this example, the catalyst was replaced with 3% Ru-3% Cu/TS-1 catalyst, and the remaining conditions and production method were the same as in example 1, whereby 26.14g of p-phenylenediamine was obtained as a product having a purity of 99.87%.
Example 9
The same as example 1, a process for preparing p-phenylenediamine from aniline was provided, except that in this example the catalyst was replaced with 0.1% Ru-0.1% Cu/TS-1 catalyst, and the remaining conditions and preparation were the same as in example 1, to provide the product p-phenylenediamine, 21.36g, having a purity of 99.90%.
Comparative example 1
This comparative example provides a process for the preparation of o-phenylenediamine from aniline, which differs from example 1 in that 4.65g of 0.5% Cu/TS-1 is used as catalyst, the remaining reagents and reaction conditions are the same as in example 1, and the final product, p-phenylenediamine, is 3.24g, with a purity of 99.91%.
The preparation method of the 0.5% Cu/TS-1 catalyst comprises the following steps:
1.48g of copper nitrate is weighed and dissolved in 10m L deionized water to form a mixed solution, the mixed solution is dipped in 100g of TS-1 molecular sieve carrier in the same volume, and the rest steps are the same as the preparation method of the catalyst 0.5 percent Ru-0.5 percent Cu/TS-1.
Comparative example 2
This comparative example provides a process for the preparation of o-phenylenediamine from aniline, which differs from example 1 in that 4.65g of 0.5% Ru/TS-1 is used as catalyst, the remaining reagents and reaction conditions are the same as in example 1, and the final product, p-phenylenediamine, is 18.84g, with a purity of 99.91%.
Wherein, the preparation method of the 0.5 percent Ru/TS-1 catalyst comprises the following steps:
1.02g of ruthenium trichloride is weighed and dissolved in 10m L deionized water to form a mixed solution, the mixed solution is dipped in 100g of TS-1 molecular sieve carrier in the same volume, and the rest steps are the same as the preparation method of the catalyst 0.5 percent Ru-0.5 percent Cu/TS-1.
Comparative example 3
This comparative example provides a process for the preparation of p-phenylenediamine, which differs from example 1 in that the catalyst is replaced with 0.5% Pt-0.5% Cu/TS-1 catalyst, and the remaining conditions and preparation are the same as in example 1; 19.47g of p-phenylenediamine product with the purity of 99.90 percent is obtained.
Wherein the preparation method of the 0.5 percent Pt-0.5 percent Cu/TS-1 catalyst comprises the following steps:
1.33g of chloroplatinic acid and 1.48g of copper nitrate are weighed and dissolved in 20m L deionized water to form a mixed solution, the mixed solution is immersed in 100g of TS-1 molecular sieve carrier in the same volume, and the rest steps are the same as the preparation method of the catalyst 0.5 percent Ru-0.5 percent Cu/TS-1.
Comparative example 4
This comparative example provides a process for producing p-phenylenediamine, which differs from example 1 in that p-toluenesulfonyl chloride is replaced with 66.5g (0.5mol) of trifluoroacetyl chloride, and the conditions and production process are the same as in example 1, and no p-phenylenediamine is obtained.
Analysis of results
Statistics were made on the yield, purity and selectivity of the reaction of p-phenylenediamine in examples 1-8 and comparative examples 1-4. Wherein, the yield of the p-phenylenediamine is calculated by taking the yield of the raw material aniline which is converted into the p-phenylenediamine as 100 percent theoretically, and the content of the p-aminophenol in the product is obtained by gas chromatography analysis.
The final yields, selectivities and purities of p-phenylenediamine in the examples and comparative examples are shown in table 1:
TABLE 1
From the above table, in example 5, when 1.0% Ru-1.0% Cu/TS-1 is used as the catalyst, the amount of the catalyst is 20% of the mass of the aniline, and the molar ratio of the oxidant to the aniline is 3:1, the yield of the product is the highest, which can reach 82%, as can be seen from comparison among examples 1, 8 and 9, the metal loading and the usage of the catalyst Ru-Cu/TS-1 can affect the yield of p-phenylenediamine, and if the loading of ruthenium in the molecular sieve is greater than 2% and the copper loading is greater than 2%, and the total loading of the two is greater than 5%, the selectivity of the reaction can be affected, which leads to an increase of byproducts, and the yield of the product is reduced; if the loading of ruthenium is less than 0.5% and the loading of copper is less than 0.5% in the molecular sieve, the total content of the ruthenium and the copper is less than 1%, the reaction selectivity is basically the same, but the yield of the product is reduced.
As can be seen from comparison of example 1 with comparative example 1, when a single copper catalyst is used, although the selectivity of the reaction is good, the product yield is low, which is less than 10%; as can be seen from comparison between example 1 and comparative example 2, when a single ruthenium catalyst is used, the selectivity of the reaction is poor, and the number of byproducts is increased, and similarly, when ruthenium is replaced by platinum in comparative example 3, the yield of the product and the selectivity of the reaction are low; as is clear from comparison of example 1 with comparative example 4, if the protecting group is replaced with a different protecting group such as trifluoroacetyl group from tosyl, p-phenylenediamine cannot be obtained. In conclusion, the purity of the p-phenylenediamine obtained by the process synthetic route provided by the invention is higher, the purity of the p-phenylenediamine is more than 99.87%, the yield is more than or equal to 40%, and the highest yield can reach 82%.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.
Claims (10)
1. A process for the preparation of p-phenylenediamine from aniline, said process comprising the steps of:
protecting amino on aniline with p-toluenesulfonyl, mixing with amino donor, oxidant and catalyst Ru-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain p-phenylenediamine.
2. Method according to claim 1, characterized in that it comprises the following steps:
(1) mixing p-toluenesulfonyl chloride, an acid-binding agent, a solvent and aniline, and reacting to obtain p-toluenesulfonyl aniline;
(2) mixing the p-toluenesulfonanilide, an amino donor, a catalyst Ru-Cu/TS-1 and a solvent, and then adding an oxidant for reaction to obtain p-aminobenzenesulfonanilide;
(3) and deprotecting the p-aminobenzene sulfonanilide, and separating to obtain the p-phenylenediamine.
3. The process of claim 2, wherein the process has a molar ratio of p-toluenesulfonyl chloride to aniline of (1-1.2): 1;
preferably, the molar ratio of aniline to oxidant in the process is 1 (1-5);
preferably, the molar ratio of aniline to amino donor in the process is 1 (1-10);
preferably, the mass ratio of the catalyst Ru-Cu/TS-1 to the aniline in the method is 1 (5-100).
4. The method according to claim 2 or 3, wherein the reaction in step (1) takes place under a nitrogen atmosphere;
preferably, the temperature of the reaction in step (1) is 50-80 ℃;
preferably, the acid-binding agent in step (1) comprises one or a combination of more than two of triethylamine, pyridine, piperidine, piperazine, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, potassium phosphate or potassium acetate;
preferably, the solvent in step (1) comprises any one or a combination of two or more of dichloromethane, tetrahydrofuran, petroleum ether or n-hexane.
5. The method according to any one of claims 2 to 4, wherein the oxidizing agent of step (2) comprises any one or a combination of two or more of hydrogen peroxide, p-benzoquinone, t-butyl peroxide, or potassium persulfate;
preferably, the amino donor of step (2) comprises ammonia water or liquid ammonia;
preferably, the mass concentration of the ammonia water is 20% -30%;
preferably, the solvent in step (2) comprises any one or a combination of two or more of acetone, methanol, ethanol, isopropanol, N '-dimethylformamide, N' -dimethylacetamide and dimethylsulfoxide;
preferably, the reaction time in the step (2) is 3-5 h;
preferably, the reaction temperature in step (2) is 50 to 150 ℃.
6. The method according to any one of claims 2 to 5, wherein the catalyst Ru-Cu/TS-1 in the step (2) is prepared by an isometric impregnation method;
preferably, the preparation method of the catalyst Ru-Cu/TS-1 comprises the following steps: and dipping the ruthenium salt solution and the copper salt solution into the TS-1 molecular sieve solution, adding alkali to adjust the pH value so as to completely precipitate ruthenium metal and copper metal in the solution, washing, drying and then reducing by hydrogen to obtain the catalyst Ru-Cu/TS-1.
7. The method as claimed in any one of claims 2 to 6, wherein the specific surface area of the TS-1 molecular sieve is 300-500m2(ii) a bulk density of from 0.45 to 0.55g/m L；
Preferably, the pore volume of the TS-1 molecular sieve is 0.45-0.8m L/g, and the catalytic water absorption capacity is 0.1-0.3 g/g;
preferably, the loading amount of Ru in the catalyst Ru-Cu/TS-1 is 0.5-2%;
preferably, the loading of Cu in the catalyst Ru-Cu/TS-1 is 0.5-2%.
8. The method according to any one of claims 2 to 7, wherein the ruthenium salt comprises any one or a combination of two or more of ruthenium trichloride, ruthenium acetate, ruthenium acetylacetonate, or ruthenium nitrosyl nitrate;
preferably, the copper salt comprises any one or a combination of more than two of copper sulfate, copper nitrate, copper chloride or copper acetate;
preferably, the alkali comprises any one or a combination of more than two of sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate;
preferably, the base is added to adjust the solution pH to 9-12;
preferably, the hydrogen reduction operation is carried out in a tubular furnace, and the reduction temperature is 350-450 ℃.
9. The method according to any one of claims 2 to 8, wherein the deprotection composition used for the deprotection in step (3) comprises any one or a combination of two or more of magnesium/methanol, hydrogen bromide/phenol, hydrogen fluoride/acetonitrile, lithium/liquid ammonia, or calcium fluoride/diatomaceous earth, preferably calcium fluoride/diatomaceous earth;
preferably, the separation in step (3) comprises any one or more of desalting, desolventizing or rectifying.
10. A method according to any of claims 2-9, characterized in that the method comprises the steps of:
(1) mixing p-toluenesulfonyl chloride, an acid-binding agent, a solvent and aniline, wherein the molar ratio of the p-toluenesulfonyl chloride to the aniline is (1-1.2):1, reacting at 50-80 ℃ under the protection of nitrogen, and carrying out rotary evaporation to obtain p-toluenesulfonyl aniline;
(2) preparing a catalyst Ru-Cu/TS-1 by using an isometric impregnation method, wherein the metal load in the catalyst Ru-Cu/TS-1 is 1-5%, mixing the p-toluenesulfonanilide, ammonia water, the catalyst Ru-Cu/TS-1 and a solvent, wherein the molar ratio of the aniline to the ammonia water is 1 (1-10), the mass ratio of the catalyst Ru-Cu/TS-1 to the aniline is 1 (5-100), adding hydrogen peroxide, wherein the molar ratio of the aniline to the hydrogen peroxide is 1 (1-5), and reacting at 50-150 ℃ for 3-5h to obtain p-aminobenzene sulfonanilide;
(3) and under the protection of inert gas, carrying out deprotection, desalting, desolventizing and rectification on the p-aminobenzenesulfonylaniline by using a deprotection composition to obtain the p-phenylenediamine.
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