CN111217712A - Method for preparing o-phenylenediamine from aniline - Google Patents
Method for preparing o-phenylenediamine from aniline Download PDFInfo
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- CN111217712A CN111217712A CN202010071768.3A CN202010071768A CN111217712A CN 111217712 A CN111217712 A CN 111217712A CN 202010071768 A CN202010071768 A CN 202010071768A CN 111217712 A CN111217712 A CN 111217712A
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- 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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Abstract
The invention provides a method for preparing o-phenylenediamine from aniline. The method comprises the following steps: protecting amino on aniline with acetyl, mixing with amino donor, oxidant and catalyst Pd-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain o-phenylenediamine. According to the invention, the amino group on the aniline is protected by acetyl group through a protecting group strategy, and the catalyst is coordinated with the carbonyl group in the acetanilide, so that the ortho-position C-H bond is induced and activated, the ortho-position selectivity is improved, the generation of byproducts is reduced, the ammoniation efficiency and selectivity can be greatly improved, the yield and the purity of o-phenylenediamine are improved, the o-phenylenediamine is directly prepared from the aniline, the environmental pollution caused by the nitration and chlorination processes is avoided, and the synthesis concept of green and environment protection is better met.
Description
Technical Field
The invention belongs to the technical field of fine chemical engineering, particularly relates to a preparation method of o-phenylenediamine, and particularly relates to a method for preparing o-phenylenediamine from aniline.
Background
The o-phenylenediamine is a traditional fine chemical intermediate, is an important intermediate of dyes, pesticides, auxiliaries, photosensitive materials and the like, can be used for preparing polyamide, carbendazim, thiophanate-methyl, vat scarlet GG, leveling agent and anti-aging agent MB, and can also be used for preparing developing agents, surfactants and the like.
The major synthetic routes currently include the ortho-nitrochlorobenzene route, the ortho-nitroaniline route, the ortho-dinitrobenzene route, and the ortho-dichlorobenzene route. The domestic industrial routes for producing o-phenylenediamine mainly comprise iron powder reduction, sodium sulfide reduction and catalytic hydrogenation. At present, the iron powder reduction process is completely eliminated, and the sodium sulfide reduction process is gradually eliminated due to the generation of a large amount of solid wastes. The catalytic hydrogenation of the o-nitroaniline is mature, which is the most widely applied industrial route at present.
CN102633653A discloses a method for preparing o-phenylenediamine by catalytic hydrogenation of o-nitroaniline, which comprises the steps of taking o-nitroaniline as a raw material, methanol as a solvent and Raney's nickel as a catalyst, reacting for 2-10 hours at 40-80 ℃ under the pressure of 1-6MPa, and rectifying to obtain the o-phenylenediamine with the product purity of 99.9%, wherein the reaction can be represented by the following chemical reaction equation:
the alcohol used for producing o-phenylenediamine by catalytic hydrogenation is used as a solvent, the alcohol can be directly used for the next batch of reaction after being recovered, the waste residue generated by distillation can be used as an organic fuel, the problem that a large amount of organic wastewater is generated by reduction of iron powder or sodium sulfide in the traditional process is solved, and meanwhile, the use of concentrated acid and concentrated alkali in the traditional process is avoided in the hydrogenation process, so that the corrosion of equipment is greatly reduced.
CN101906046A discloses a method for producing o-phenylenediamine by a liquid phase continuous hydrogenation method, in the method, methanol is used as a solvent, skeletal nickel is used as a catalyst, the reaction is carried out in a first-stage hydrogenation reaction kettle and a second-stage hydrogenation reaction kettle which are connected in series, methanol which is 50-70% of the volume of the reaction kettles is added into the first-stage hydrogenation reaction kettle and the second-stage hydrogenation reaction kettle, the catalyst which is 0.5-1.5% of the weight of the methanol is added, hydrogen is continuously introduced into the first-stage hydrogenation reaction kettle and the second-stage hydrogenation reaction kettle under the stirring state, and the o-phenylenediamine product is obtained by rectification, wherein the purity is 99.9.
US3230259 discloses a method for preparing o-phenylenediamine, which comprises reacting 5% Pd/C as a catalyst, sodium hydroxide as an auxiliary agent, and water as a solvent at 70-100 deg.C for 5h to obtain an o-phenylenediamine with a yield of 95% or more.
However, although the catalytic hydrogenation for producing o-phenylenediamine is a mainstream production process at present, the hydrogen is used in the hydrogenation reduction reaction, and the safety risk is high.
CN105037171A relates to a synthetic method for preparing o-phenylenediamine from o-dichlorobenzene, which comprises the steps of putting o-dichlorobenzene, a copper catalyst and a ligand into a high-pressure kettle, then putting liquid ammonia or ammonia water into the high-pressure kettle, discharging, transferring into a distillation kettle, and carrying out vacuum distillation to obtain white o-phenylenediamine, wherein the reaction can be represented by the following chemical reaction equation:
the method takes o-dichlorobenzene as a raw material, directly prepares o-phenylenediamine by ammoniation, adopts a strong power supply ligand to improve the activity of a copper catalyst, reduces the reaction difficulty, has mild reaction conditions, obviously improves the reaction efficiency and the reaction yield, and is suitable for industrial production.
CN1594279A discloses a method for preparing o-diphenylamine by ammoniating o-dichlorobenzene, liquid ammonia and a copper catalyst. The process of producing o-phenylenediamine includes the ammonolysis reaction of o-dichlorobenzene and ammonia in high temperature and high pressure container under the action of catalyst, analysis and separation of the obtained reactant, and continuous ammonolysis reaction of o-dichlorobenzene, liquid ammonia, copper catalyst and phase transfer catalyst in a pipeline reactor.
CN104262170A discloses a preparation method of o-phenylenediamine, which comprises the following steps: adding o-chloroaniline into a high-pressure amination kettle, introducing liquid ammonia, and reacting for 5-10 hours at 100-150 ℃ under the heat preservation of 2.0-6 MPa. After the reaction is finished, cooling to room temperature, releasing the pressure to 0.2MPa, pressing the reactant into a washing kettle by using a pump for washing, removing ammonium chloride, and further refining the product by using ethanol to obtain the o-phenylenediamine.
However, the raw materials of the o-dichlorobenzene route are easy to obtain, the process flow is short, but the ammonolysis reaction is carried out under the conditions of high temperature and high pressure, the equipment investment is large, a large amount of waste water containing ammonium chloride is generated, and the treatment difficulty of three wastes is large.
Therefore, the development of a technological synthetic route for preparing o-phenylenediamine, which has mild reaction conditions and fewer three wastes, is a problem to be solved urgently at present.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide a method for preparing o-phenylenediamine from aniline. The synthetic route provided by the invention is used for preparing o-phenylenediamine, the yield and purity of the obtained o-phenylenediamine are higher, the by-products are fewer, the synthetic route is simpler, and the reaction conditions are mild.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a method for preparing o-phenylenediamine from aniline, which comprises the following steps: protecting amino on aniline with acetyl, mixing with amino donor, oxidant and catalyst Pd-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain o-phenylenediamine.
In the invention, TS-1 is a titanium-silicon molecular sieve, palladium metal (Pd) and copper metal (Cu) are combined on TS-1 to be used as a catalyst Pd-Cu/TS-1, and the reaction efficiency can be greatly improved; meanwhile, the catalyst is coordinated with carbonyl in acetanilide, so that an ortho-position C-H bond is induced and activated, ortho-position selectivity is improved, generation of byproducts is reduced, o-phenylenediamine is directly prepared from aniline, environmental pollution caused by nitration and chlorination processes is avoided, and the synthesis concept of green and environment protection is better met.
Preferably, the method comprises the steps of:
(1) mixing acetyl chloride, an acid-binding agent (Deacid Reagent), a solvent and the aniline and then reacting to obtain acetanilide;
(2) mixing the acetanilide, the amino donor, the catalyst Pd-Cu/TS-1 and a solvent, and then adding the oxidant for reaction to obtain o-amino acetanilide;
(3) and deprotecting the o-amino acetanilide and separating to obtain the o-phenylenediamine.
As a preferred embodiment of the present invention, the molar ratio of acetyl 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.
Preferably, the molar ratio of aniline to oxidant in the process is 1 (2-5), and may be, for example, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or the like.
Preferably, the molar ratio of aniline to amino donor in the process is 1 (2-10), and may be, for example, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:5, 1:5.5, 1:6, 1:7, 1:8, or 1:10, etc.
Preferably, the mass ratio of the catalyst Pd-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 comprises one or more of triethylamine, pyridine, piperidine, piperazine, sodium hydroxide, sodium carbonate, potassium phosphate and potassium acetate.
Preferably, the solvent in step (1) comprises any one or a combination of two or more of acetone, tetrahydrofuran or ethanol.
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 in step (2) comprises liquid ammonia or aqueous 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 (DMF), N' -dimethylacetamide (DMAc), or Dimethylsulfoxide (DMSO).
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 reaction pressure in step (2) is 99 to 101KPa, for example, 99KPa, 99.5KPa, 100KPa, 100.2KPa, 100.5KPa, 100.8KPa, 101KPa, etc.
As a preferable technical scheme of the invention, the catalyst Pd-Cu/TS-1 in the step (2) is prepared by using an isometric impregnation method.
Preferably, the preparation method of the catalyst Pd-Cu/TS-1 comprises the following steps: and (2) dipping the palladium salt solution and the copper salt solution into the TS-1 molecular sieve solution, adding alkali to adjust the pH value to ensure that palladium metal and copper metal in the solution are completely precipitated, washing, drying and then reducing by hydrogen to obtain the catalyst Pd-Cu/TS-1.
Preferably, the specific surface area of the TS-1 molecular sieve is 300-500m2G, may be, for example, 300m2/g、320m2/g、350m2/g、380m2/g、400m2/g、420m2/g、450m2/g、480m2G or 500m2(iv)/g, etc.; the bulk density is 0.45 to 0.55g/mL, and may be, for example, 0.45g/mL, 0.46g/mL, 0.47g/mL, 0.48g/mL, 0.49g/mL, 0.50g/mL, 0.51g/mL, 0.52g/mL, 0.53g/mL, 0.54g/mL or 0.55 g/mL.
Preferably, the TS-1 molecular sieve has a pore volume of 0.45-0.8mL/g, such as 0.45mL/g, 0.50mL/g, 0.55mL/g, 0.60mL/g, 0.65mL/g, 0.70mL/g, 0.75mL/g, 0.78mL/g, or 0.8 mL/g; the catalytic water absorption amount may be, for example, 0.1 to 0.3g/g, and may be, for example, 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 0.3 g/g.
Preferably, the Pd loading in the catalyst Pd-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.
Preferably, the loading amount of Cu in the catalyst Pd-Cu/TS-1 is 0.5-2%, for example, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.6%, 1.8%, 2%, etc.
In a preferred embodiment of the present invention, the palladium salt includes any one or a combination of two or more of chloropalladate, ammonium chloropalladate, palladium nitrate and palladium acetate.
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 tube furnace, the reduction temperature is 350-450 ℃, for example, 350 ℃, 355 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃ or 450 ℃.
In a preferred embodiment of the present invention, the deprotecting agent used in the deprotection in step (3) comprises any one or a combination of two or more of sodium methoxide/methanol (indicating that sodium methoxide and methanol are used in combination), potassium hydroxide/ethanol, hydrochloric acid/methanol, hydrochloric acid/ethanol, and schwarz's reagent.
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 acetyl chloride, an acid-binding agent, a solvent and aniline, wherein the molar ratio of the acetyl chloride to the aniline is (1-1.2):1, reacting at 50-80 ℃ under the protection of nitrogen, and performing rotary evaporation to obtain acetanilide;
(2) preparing a catalyst Pd-Cu/TS-1 by using an isometric impregnation method, wherein the metal loading amount in the catalyst Pd-Cu/TS-1 is 1-5%, mixing the acetanilide, ammonia water, the catalyst Pd-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 Pd-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 o-amino acetanilide;
(3) under the protection of inert gas, carrying out deprotection on the o-amino acetanilide by using a deprotection agent, desalting, desolventizing and rectifying to obtain the o-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 o-phenylenediamine provided by the invention, aniline is used as a preparation raw material, acetyl is adopted to protect amino, Pd-Cu/TS-1 is used as a catalyst, and amino is introduced to the ortho position of aniline to obtain o-phenylenediamine;
(2) the synthetic route provided by the invention has mild reaction conditions, solves the problem of severe requirements on equipment in the prior art, reduces the generation of byproducts, directly prepares the o-phenylenediamine from the aniline, avoids environmental pollution caused by nitration and chlorination processes, and is more in line with the green and environment-friendly synthetic concept;
(3) the synthetic route provided by the invention has higher yield, the yield of the product o-phenylenediamine is more than or equal to 38%, the purity of the product can be effectively improved, and the purity of the o-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 solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
In the following examples, the TS-1 molecular sieve can be prepared using the following method:
22.5g of tetraethyl orthosilicate (TEOS), 7.0g of tetrapropylammonium hydroxide (TPAOH) and 1g of gamma-glycidoxypropyltrimethoxysilane are mixed, 59.8g of distilled water is added, and after uniform stirring and mixing, hydrolysis is carried out for 1h under the conditions of normal pressure and 60 ℃ 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.
The finally prepared TS-1 molecular sieve is used as a catalyst carrier, the diameter of the catalyst carrier is 1mm, and the specific surface area of the catalyst carrier is 350m2The specific weight ratio of the catalyst to the water is 0.45-0.55 g/g, the bulk density is 0.45-0.55g/mL, the pore volume is 0.45-0.8mL/g, and the catalytic water absorption capacity is 0.2 g/g.
In the following examples, TS-1 catalysts with varying Pd-Cu contents were prepared with palladium and copper salts.
(1) Taking 0.5 percent Pd-0.5 percent Cu/TS-1 of the catalyst prepared by palladium nitrate and copper nitrate as an example, the preparation method comprises the following steps:
weighing 1.08g of palladium nitrate and 1.48g of copper nitrate, dissolving the palladium nitrate and the copper nitrate in 20mL of deionized water to form a mixed solution, soaking the mixed solution in the same volume, transferring the mixed solution to an oven at 80 ℃ for drying for 12 hours, drying a 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) till the pH value of the final system is 10 to ensure that the precipitation is complete, adding deionized water to wash until the conductivity is 50S/m, and then drying in an oven at 110 ℃;
transferring the loaded TS-1 molecular sieve into a tubular furnace, setting the hydrogen flow rate at 100mL/min, carrying out temperature programming at the speed of 5 ℃/min to 350 ℃, carrying out heat preservation at 350 ℃ for 2h to obtain a 0.5% Pd-0.5% Cu/TS-1 catalyst, cooling the reduced catalyst to room temperature, introducing 0.5% diluted oxygen-nitrogen release mixed gas, and carrying out passivation treatment for 30min to obtain 101g of the 0.5% Pd-0.5% Cu/TS-1 catalyst.
(2) Taking 0.5 percent Pd-1 percent Cu/TS-1 of catalyst prepared by palladium acetate and copper sulfate as an example, the specific preparation method comprises the following steps:
weighing 2.11g of palladium acetate and 1.98g of copper sulfate, dissolving the palladium acetate and the copper sulfate in 20mL of deionized water to form a mixed solution, soaking the mixed solution in the same volume, transferring the soaked mixed solution to an oven at 80 ℃ for drying for 12 hours, cooling the dried molecular sieve carrier to room temperature, adding 1% of NaOH and Na in a measured amount into the molecular sieve carrier2CO3The final system pH was 10 to complete precipitation by mixing 2:1 lye, washing with deionized water to a conductivity of 50S/m, and then drying in an oven at 110 ℃.
And transferring the loaded TS-1 pellets into a tubular furnace, setting the hydrogen flow rate at 100mL/min, carrying out temperature programming at the speed of 5 ℃/min to 350 ℃, carrying out heat preservation at 350 ℃ for 2h to obtain a 1% Pd-0.5% Cu/TS-1 catalyst, cooling the reduced catalyst to room temperature, introducing 0.5% diluted oxygen-nitrogen release mixed gas, and carrying out passivation treatment for 30min to obtain 101.5g of the 1% Pd-0.5% Cu/TS-1 catalyst.
Example 1
This example provides a method for preparing o-phenylenediamine from aniline, comprising the following steps:
(1) adding 470g of acetone (8.1mol), 46.5g of aniline (0.5mol) and 50g of acid-binding agent triethylamine (0.5mol) into a flask, slowly dropwise adding 39.5g (0.5mol) of acetyl chloride solution into the flask under the conditions of ice-water bath and stirring, tracking by TLC until the reaction is complete, filtering insoluble substances in the system, and removing the solvent by rotary evaporation to obtain acetanilide crystals;
(2) acetanilide, 580g of propanol (10.0mol), 212.5g of 20 wt% aqueous ammonia (2.5mol), 190g of an oxidizing agent H2O2(1.5mol) and 6.98g of 0.5 percent Pd-0.5 percent Cu/TS-1 catalyst are added into a high-pressure reaction kettle, the reaction temperature is set to be 85 ℃, the reaction is finished after the magnetic stirring reaction is carried out for 4 hours, the catalyst is filtered and separated, and unreacted raw acetanilide and a crude product of the product are separated by column chromatography;
(3) adding sodium methoxide/methanol solution (the mass ratio of sodium methoxide to methanol is 1:4) into the crude product, carrying out deprotection in an ice water bath, tracking by TLC until the deprotection is complete, desalting, desolventizing and rectifying to obtain a product o-phenylenediamine of 24.33g, analyzing the obtained product by using gas chromatography (Agilent 8890), and detecting to obtain a gas chromatogram which is shown in figure 1, wherein the peak about 1.8min is a solvent peak, the peak-off time of the product is 8.779min and is the same as the peak-off time of a standard o-phenylenediamine, so that the obtained product is o-phenylenediamine and the purity is 99.92%.
Example 2
This example provides a method for preparing o-phenylenediamine from aniline, comprising the following steps:
(1) adding 470g of acetone (8.1mol), 46.5g of aniline (0.5mol) and 20g of acid-binding agent sodium hydroxide (0.5mol) into a flask, slowly and dropwise adding 39.5g (0.5mol) of acetyl chloride solution into the flask under the conditions of ice-water bath and stirring, tracking by TLC until the reaction is complete, filtering insoluble substances in the system, and removing the solvent by rotary evaporation to obtain acetanilide crystals;
(2) acetanilide 730g of DMF (10.0mol), 425g of 20% aqueous ammonia (5.0mol), 190g of oxidizing agent H2O2(1.5mol) and 4.65g of 1.0 percent Pd-0.5 percent Cu/TS-1 catalyst are added into a high-pressure reaction kettle, the reaction temperature is set to be 150 ℃, the reaction is finished after 4 hours of magnetic stirring, the catalyst is filtered and separated, and unreacted raw acetanilide and a crude product of the product are separated by column chromatography;
(3) adding an ethanol solution containing 5 wt% of potassium hydroxide into the crude product, carrying out deprotection in an ice water bath, tracking by TLC until the deprotection is complete, and obtaining 25.95g of o-phenylenediamine through desalting, desolventizing and rectifying, wherein the purity of the obtained product is 99.98%.
Example 3
This example provides a method for preparing o-phenylenediamine from aniline, comprising the following steps:
(1) adding 576g of tetrahydrofuran (8.0mol), 46.5g of aniline (0.5mol) and 49g of acid-binding agent potassium acetate (0.5mol) into a flask, slowly dripping 39.5g (0.5mol) of acetyl chloride solution into the flask under the conditions of ice-water bath and stirring, tracking by TLC until the reaction is complete, filtering insoluble substances in the system, and removing the solvent by rotary evaporation to obtain acetanilide crystals;
(2) acetanilide, 600g of isopropanol (10.0mol), 85g of 20% ammonia water (1.0mol), 127g of an oxidizing agent H2O2(1.0mol) and 4.65g of 1.5 percent Pd-1.5 percent Cu/TS-1 catalyst are added into a high-pressure reaction kettle, the reaction temperature is set to be 50 ℃, the reaction is finished after 4 hours of magnetic stirring, the catalyst is filtered and separated, and unreacted raw acetanilide and a crude product of the product are separated by column chromatography;
(3) adding a methanol solution containing 3 wt% of hydrochloric acid into the crude product, carrying out deprotection in an ice water bath, tracking by TLC until the deprotection is complete, and obtaining a product o-phenylenediamine 20.55g with the purity of 99.96% through desalting, desolventizing and rectifying.
Example 4
This example provides a method for preparing o-phenylenediamine from aniline, comprising the following steps:
(1) adding 470g of acetone (8.1mol), 46.5g of aniline (0.5mol) and 50g of acid-binding agent triethylamine (0.5mol) into a flask, slowly dropwise adding 39.5g (0.5mol) of acetyl chloride solution into the flask under the conditions of ice-water bath and stirring, tracking by TLC until the reaction is complete, filtering insoluble substances in the system, and removing the solvent by rotary evaporation to obtain acetanilide crystals;
(2) acetanilide, 600g of isopropanol (10.0mol), 255g of 20% ammonia water (3.0mol), 317g of an oxidizing agent H were taken2O2(2.5mol) and 9.3g of 1.5 percent Pd-1.5 percent Cu/TS-1 catalyst are added into a high-pressure reaction kettle, the reaction temperature is set to be 85 ℃, the reaction is finished after the magnetic stirring reaction is carried out for 4 hours, the catalyst is filtered and separated, and unreacted raw acetanilide and a crude product of the product are separated by column chromatography;
(3) adding sodium methoxide/methanol solution (the mass ratio of sodium methoxide to methanol is 1:4) into the crude product, carrying out deprotection in an ice water bath, tracking by TLC until the deprotection is complete, and obtaining a product o-phenylenediamine 45.95g with the purity of 99.93 percent through desalting, desolventizing and rectifying.
Example 5
This example provides a method for preparing o-phenylenediamine from aniline, comprising the following steps:
(1) adding 375g of ethanol (8.1mol), 46.5g of aniline (0.5mol) and 50g of acid-binding agent triethylamine (0.5mol) into a flask, slowly dripping 39.5g (0.5mol) of acetyl chloride solution into the flask under the conditions of ice-water bath and stirring, tracking by TLC until the reaction is complete, filtering insoluble substances in the system, and removing the solvent by rotary evaporation to obtain acetanilide crystals;
(2) acetanilide, 600g of isopropanol (10.0mol), 212.5g of 20% ammonia water (2.5mol), 190g of an oxidizing agent H2O2(1.5mol) and 5.8g of 1.5 percent Pd-1.5 percent Cu/TS-1 catalyst are added into a high-pressure reaction kettle, the reaction temperature is set to 65 ℃, the reaction is finished after 4 hours of magnetic stirring, the catalyst is filtered and separated, and unreacted raw acetanilide and a crude product of the product are separated by column chromatography;
(3) adding sodium methoxide/methanol solution (the mass ratio of sodium methoxide to methanol is 1:4) into the crude product, carrying out deprotection in an ice water bath, tracking by TLC until the deprotection is complete, and obtaining 27.13g of o-phenylenediamine with the purity of 99.95% by desalting, desolventizing and rectifying.
Example 6
The same as example 1, except that in this example, ammonia water was replaced with 42.5g (2.5mol) of liquid ammonia, a process for producing o-phenylenediamine from aniline was provided, and the conditions and production process were the same as in example 1, whereby 27.32g of o-phenylenediamine was obtained with a purity of 99.94%.
Example 7
The same as example 1, except that hydrogen peroxide was replaced with 135g (1.5mol) of t-butyl peroxide, and the other conditions and preparation method were the same as example 1, to obtain 21.95g of o-phenylenediamine with a purity of 99.90%.
Example 8
As in example 1, a process for the preparation of o-phenylenediamine from aniline is provided, except that in this example the catalyst is replaced with 3% Pd-3% Cu/TS-1 catalyst, and the remaining conditions and preparation are the same as in example 1, to provide the product o-phenylenediamine, 20.77g, with a purity of 99.91%.
Example 9
As in example 1, a process for producing o-phenylenediamine from aniline was provided, except that in this example the catalyst was replaced with 0.1% Pd-0.1% Cu/TS-1 catalyst, and the remaining conditions and production process were the same as in example 1, to obtain 20.38g of o-phenylenediamine product having a purity of 99.96%.
Comparative example 1
This comparative example provides a process for the preparation of o-phenylenediamine from aniline, which differs from example 1 in that 6.98g of 1% Cu/TS-1 is used as catalyst, the remaining reagents and reaction conditions are the same as in example 1, and the finally obtained o-phenylenediamine has a mass of 4.41g and a purity of 99.93%;
the preparation method of the 1% Cu/TS-1 catalyst comprises the following steps:
weighing 1.98g of copper sulfate, dissolving in 20mL of deionized water to form a mixed solution, soaking in 100g of TS-1 molecular sieve carrier in the same volume, and performing the other steps in the same way as the preparation method of the catalyst of 0.5% Pd-0.5% 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 6.98g of 1% Pd/TS-1 is used as catalyst, the remaining reagents and reaction conditions are the same as in example 1, and the finally obtained o-phenylenediamine has a mass of 17.26g and a purity of 99.95%;
wherein, the preparation method of the 1% Pd/TS-1 catalyst comprises the following steps:
weighing 2.16g of palladium nitrate, dissolving the palladium nitrate in 20mL of deionized water to form a mixed solution, soaking the mixed solution in 100g of TS-1 molecular sieve carrier in the same volume, and performing the rest steps in the same way as the preparation method of the catalyst of 0.5% Pd-0.5% Cu/TS-1. .
Comparative example 3
This comparative example provides a process for the preparation of o-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; the product o-phenylenediamine (16.87 g) is obtained, and the purity is 99.93%.
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 20mL of 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 Pd-0.5 percent Cu/TS-1.
Comparative example 4
This comparative example provides a process for producing o-phenylenediamine, which differs from example 1 in that 95.5g (0.5mol) of acetyl chloride is replaced with p-toluenesulfonyl chloride, and the conditions and the production process are the same as those in example 1, and no o-phenylenediamine is obtained.
Analysis of results
Statistics were made on the yield, purity and selectivity of the reaction of the o-phenylenediamine in examples 1 to 8 and comparative examples 1 to 4. Wherein the yield of o-phenylenediamine is calculated by taking the yield of all o-phenylenediamine converted from aniline as a theoretical raw material as 100%, and the content of o-aminophenol in the product is obtained by gas chromatography analysis.
The yield, selectivity and purity of o-phenylenediamine in the final examples and comparative examples are shown in table 1:
TABLE 1
As is clear from Table 1, in example 4, the molar ratio of aqueous ammonia to aniline was 6:1, and H was2O2The molar ratio of the catalyst to the aniline is 5:1, and when the using amount of the catalyst is 20% of the mass of the aniline, the yield of the obtained o-phenylenediamine is the highest; and as can be seen from the comparison between the example 1 and the example 8, if the palladium content in the molecular sieve is more than 2%, the copper content is more than 2%, and the total content of the palladium content and the copper content in the molecular sieve is more than 5%, the selectivity of the reaction is affected, the number of by-products is increased, and the yield of the product is reduced; as can be seen from the comparison between example 1 and example 9, if the palladium content in the molecular sieve is less than 0.5%, the copper content is less than 0.5%, and the total content of the two is less than 1%, the reaction selectivity is substantially 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 was used, the product yield was low although the purity and selectivity of the product were high; it is understood from example 1 and comparative example 2 that the use of palladium alone is inferior in reaction selectivity and the increase of by-products, and from example 1 and comparative example 3, the substitution of palladium for platinum in the catalyst is inferior in yield and reaction selectivity to example 1, and from comparative example 4, when the protecting group is substituted for p-toluenesulfonyl group, o-phenylenediamine cannot be obtained. In conclusion, the purity of the o-phenylenediamine obtained by the process synthetic route provided by the invention is higher, the purity of the o-phenylenediamine is more than 99.9%, the yield is more than or equal to 38%, and the highest yield can reach 85%.
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 o-phenylenediamine from aniline, said process comprising the steps of:
protecting amino on aniline with acetyl, mixing with amino donor, oxidant and catalyst Pd-Cu/TS-1 to produce ammoniation reaction, deprotection and separation to obtain o-phenylenediamine.
2. Method according to claim 1, characterized in that it comprises the following steps:
(1) mixing acetyl chloride, an acid-binding agent, a solvent and the aniline and then reacting to obtain acetanilide;
(2) mixing the acetanilide, the amino donor, the catalyst Pd-Cu/TS-1 and a solvent, and then adding the oxidant for reaction to obtain o-amino acetanilide;
(3) and deprotecting the o-amino acetanilide and separating to obtain the o-phenylenediamine.
3. The process according to claim 2, wherein the molar ratio of acetyl chloride to aniline in the process is (1-1.2): 1;
preferably, the molar ratio of aniline to oxidant in the process is 1 (2-5);
preferably, the molar ratio of aniline to amino donor in the process is 1 (2-10);
preferably, the mass ratio of the catalyst Pd-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 comprises one or a combination of more than two of triethylamine, pyridine, piperidine, piperazine, sodium hydroxide, sodium carbonate, potassium phosphate or potassium acetate;
preferably, the solvent in step (1) comprises any one or a combination of two or more of acetone, tetrahydrofuran or ethanol.
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 liquid ammonia or aqueous 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 dimethyl sulfoxide;
preferably, the reaction time in the step (2) is 3-5 h;
preferably, the temperature of the reaction in step (2) is 50-150 ℃;
preferably, the pressure of the reaction in step (2) is from 99 to 101 KPa.
6. The method according to any one of claims 2 to 5, wherein the catalyst Pd-Cu/TS-1 in the step (2) is prepared by an equal volume impregnation method;
preferably, the preparation method of the catalyst Pd-Cu/TS-1 comprises the following steps: and (2) dipping the palladium salt solution and the copper salt solution into the TS-1 molecular sieve solution, adding alkali to adjust the pH value to ensure that palladium metal and copper metal in the solution are completely precipitated, washing, drying and then reducing by hydrogen to obtain the catalyst Pd-Cu/TS-1.
7. The method of any one of claims 2 to 6, wherein the TS-1 molecular sieve has a specific surface area of from 300 to 500m2(ii)/g, bulk density 0.45-0.55 g/mL;
preferably, the pore volume of the TS-1 molecular sieve is 0.45-0.8mL/g, and the catalytic water absorption capacity is 0.1-0.3 g/g;
preferably, the load of Pd in the catalyst Pd-Cu/TS-1 is 0.5-2%;
preferably, the loading of Cu in the catalyst Pd-Cu/TS-1 is 0.5-2%.
8. The method according to any one of claims 2-7, wherein the palladium salt comprises any one or a combination of two or more of chloropalladate, ammonium chloropalladate, palladium nitrate, or palladium acetate;
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 is carried out in a tube furnace at a reduction temperature of 350-450 ℃.
9. The method according to any one of claims 2 to 8, wherein the deprotection agent used for the deprotection in step (3) comprises any one or a combination of two or more of sodium methoxide/methanol, potassium hydroxide/ethanol, hydrochloric acid/methanol, hydrochloric acid/ethanol, or schwarz's reagent;
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 acetyl chloride, an acid-binding agent, a solvent and aniline, wherein the molar ratio of the acetyl chloride to the aniline is (1-1.2):1, reacting at 50-80 ℃ under the protection of nitrogen, and performing rotary evaporation to obtain acetanilide;
(2) preparing a catalyst Pd-Cu/TS-1 by using an isometric impregnation method, wherein the metal loading amount in the catalyst Pd-Cu/TS-1 is 1-5%, mixing the acetanilide, ammonia water, the catalyst Pd-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 Pd-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 o-amino acetanilide;
(3) under the protection of inert gas, carrying out deprotection on the o-amino acetanilide by using a deprotection agent, desalting, desolventizing and rectifying to obtain the o-phenylenediamine.
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