CN106588618B - A method of the Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone of catalyst containing selenium - Google Patents
A method of the Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone of catalyst containing selenium Download PDFInfo
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- CN106588618B CN106588618B CN201610964223.9A CN201610964223A CN106588618B CN 106588618 B CN106588618 B CN 106588618B CN 201610964223 A CN201610964223 A CN 201610964223A CN 106588618 B CN106588618 B CN 106588618B
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C46/00—Preparation of quinones
- C07C46/02—Preparation of quinones by oxidation giving rise to quinoid structures
- C07C46/06—Preparation of quinones by oxidation giving rise to quinoid structures of at least one hydroxy group on a six-membered aromatic ring
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
- B01J31/06—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing polymers
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
- B01J2231/70—Oxidation reactions, e.g. epoxidation, (di)hydroxylation, dehydrogenation and analogues
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Abstract
The present invention relates to a kind of methods of the Phenol by Hydrogen Peroxide of catalyst containing selenium oxidative synthesis 1,4-benzoquinone.The object of the present invention is to provide a kind of Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone methods of catalyst containing selenium, and the method reaction condition is mild, and normal pressure can be realized.The technical solution for completing foregoing invention task is as follows: by phenol, solvent, selenium catalyst, hydrogen peroxide, it puts into glass reaction bottle, it reacts at a certain temperature, obtained oxidation solution is by analysis, phenol conversion about 30-50%, 1,4-benzoquinone selectivity 80-90%, no benzenediol and ortho isomer generate.1,4-benzoquinone by hydrogenating reduction can be highly selective obtain hydroquinone.
Description
Technical field
The present invention relates to a kind of methods of the Phenol by Hydrogen Peroxide of catalyst containing selenium oxidative synthesis 1,4-benzoquinone.
Background technique
1,4-benzoquinone, yellow crystal.Flammable, 116 DEG C of fusing point, relative density 1.318g/ml is dissolved in ethyl alcohol, ether and alkali, micro-
It is dissolved in water.It can distil, steam is volatile, and decomposed.There is the penetrating odor of similar chlorine.Be a kind of important dyestuff and
Medicine intermediate draws for being used as the raw material of manufacture hydroquinone and rubber antioxidant as acrylonitrile and vinyl acetate polymerization
Send out agent and oxidant etc..
The production technology of 1,4-benzoquinone is mainly aniline oxidizing process.Aniline is in H2SO4Through MnO in medium2Or Na2Cr2O7Oxidation
Advantage for 1,4-benzoquinone, the method is technical maturity.But the method is the problem is that the consumption of pyrolusite is big, in production process
Generate a large amount of manganese sulfate, ammonium sulphate waste liquor is difficult to handle, seriously pollute environment；On the other hand, acid system has corruption to equipment
Erosion effect, improves production cost.The environmental protection pressure of aniline oxidizing process increasingly increases severely, it will is gradually eliminated.
Recent study personnel begin one's study phenol oxygen or oxygen-containing gas oxidative synthesis 1,4-benzoquinone, such as
CN104557487A, CN104292096A and CN104292095A provide a kind of preparation method of 1,4-benzoquinone compound, with benzene
Phenolic compounds is raw material, uses oxygen or oxygen-containing gas as oxidant in liquid solvent, in transistion metal compound main reminder
Agent and N- replace under hydrocarbon oxy compound or the effect of starlike molecule co-catalyst, and selectivity prepares 1,4-benzoquinone in a mild condition
Compound.This method is needed using high-tension apparatus, and oxygen pressure needs highest 7.0MPa, has higher requirements to equipment, is used simultaneously
There are certain security risks for oxygen.CN103420803B is oxygen source using ozone, equally exists security risk.
Also researcher explores Phenol by Hydrogen Peroxide oxidizing process, such as CN103570506B, using phenol and hydrotalcite (catalysis
Agent), hydrogen peroxide is added, but in addition to obtaining 1,4-benzoquinone, there are also adjacent benzoquinones in product, need to carry out the separation of isomers, it is subsequent
It handles comparatively laborious；
It is raw material that there are also researchers using hydroquinone, 1,4-benzoquinone, such as CN104844439A is synthesized, due to benzene two
The price of phenol differs larger with 1,4-benzoquinone, therefore this method is without economy.
Summary of the invention
The object of the present invention is to provide a kind of Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium, the methods
Reaction condition is mild, and normal pressure can be realized.
Phenol and hydrogen peroxide synthesize hydroquinone under the catalysis of molecular sieve (TS-1), this is the synthesis of phenol hydroxylation method to benzene
The industrialized producing technology of diphenol, but product has more than half for catechol after reacting.By screening catalyst discovery, make
Hydrogen peroxide can be catalyzed by phenol high-selectivity oxidation at 1,4-benzoquinone, without generating benzenediol, selection with one kind catalyst containing selenium
Property reach as high as 90% or so, and there is no ortho isomer, be a completely new environmentally protective 1,4-benzoquinone synthetic route.
The technical solution for completing foregoing invention task is as follows: by phenol, solvent, selenium catalyst, hydrogen peroxide, it is anti-to put into glass
Answer in bottle, react at a certain temperature, obtained oxidation solution by analysis, phenol conversion about 30-50%, 1,4-benzoquinone selectivity
80-90%, no benzenediol and ortho isomer generate.1,4-benzoquinone by hydrogenating reduction can be highly selective obtain to benzene two
Phenol.
Catalyst described in the technical program can be small molecule selenium catalyst, as benzene seleninic acid, diphenyl disenenide ether,
Two (p-methoxyphenyl) diselenides, dicyclohexyl diselenide, two (N, N- dimethylamino phenyl) diselenides, two (chlorphenyls) two
Selenide, dibutyl diselenide etc. are also possible to the selenium catalyst of Polymer-supported, such as loaded by polystyrene selenium catalyst (polyphenyl
Ethylene loads selenium catalyst preparation process and refers to J.Mater.Chem.A, 2016,4,10828-10833)；
Solvent of the present invention can be alcohols, organic nitrile, halogenated hydrocarbons etc., such as methanol, ethyl alcohol, isopropanol, positive fourth
Alcohol, dichloroethanes, trichloroethanes, acetonitrile etc.；
Catalytic amount is the 0.5-5wt%, preferably 0.2- of phenol quality in oxidation process conditions of the present invention
3wt%；Phenol concentration is 1-40wt%, preferably 5-20wt%；The mass ratio of solvent and phenol is 2.5-50:1, preferably 5-15:
1；Hydrogen peroxide concentration is 10-70wt%, preferably 25-50wt%；The mole ratio of hydrogen peroxide and phenol is 0.1-7:1, preferably
0.2-5:1；Reaction temperature is 30-100 DEG C, preferably 40-90 DEG C；Reaction time is 0.5-8 hours, preferably 1-5 hours.Aoxidize work
For skill condition to reaction result there are great influence, these factors are also the technology contents of this method.
The technical solution has the following advantages:
1) process conditions are mild, highly-safe, and equipment requirement is low.
2) can highly selective catalysis solution for oxidation of phenol with hydrogen peroxide generate 1,4-benzoquinone, without generating benzenediol and ortho position isomery
Body is a completely new environmentally protective 1,4-benzoquinone synthetic route.
3) support type selenium catalyst choice is high, is easily separated, be may be reused at least 5 times with oxidation solution, solves
Conventional grained catalyst is difficult to the problem of separating and being easy to run off.
Specific embodiment
The following examples are intended to explain protrusion effect of the invention, rather than limitation of the invention further.
The preparation process of support type selenium catalyst
In order to better illustrate the preparation process of support type selenium catalyst, now briefly introduce its preparation process (referring to
J.Mater.Chem.A, 2016,4,10828-10833): under nitrogen protection, 4g polystyrene resin soaks in 30mL cyclohexene
It is wet, tetramethylethylenediamine (37.2mmol, 5.6ml) and n-BuLi (48mmol, 26.7ml) is then added, stirring is warming up to
65-70 DEG C, 4hr, filtering are reacted, filter cake is washed with 30mL THF, filter cake is transferred in reaction flask, 40ml THF is added,
It is cooled to 0 DEG C, is added dimethyl diselenide ether (5mmol), after stirring 20min, 3mL water is added, polymer is gradually become from brown
Yellow, filtering, filter cake are successively washed with THF, water, methanol, and it is negative then to obtain pure polymer in 65 DEG C of dry r for 24 hours under vacuum
The first seleno resin of load.
Under nitrogen protection, 4g first seleno resin soaks in 60ml chloroform, and then (6mmol is molten for the chloroformic solution of addition bromine
In 20mL chloroform), at 0 DEG C, 30min, filtering are stirred, filter cake is washed with dehydrated alcohol；Filter cake is transferred in reaction flask,
60ml dehydrated alcohol is added, 2hr is reacted at 70 DEG C, material gradually becomes red, and filtering, filter cake successively uses ethyl alcohol and dichloromethane
Then alkane washing obtains the selenium bromide resin of the pure Polymer-supported of 4.25g in 65 DEG C of dry r for 24 hours under vacuum.
Under nitrogen protection, 0.7143g selenium bromide resin (1.4mmol/g) soaks in 60ml chloroform, is added 10 at 0 DEG C
Equivalent hydrogen peroxide (30wt%) stirs 2hr at room temperature, and material gradually becomes white, filtering, and filter cake successively uses ethyl alcohol and two
Chloromethanes washing, then under vacuum in 65 DEG C of dry r for 24 hours, obtain pure loaded by polystyrene selenium catalyst (0.6849g,
1.46mmol/g)。
Embodiment 1
It is sub- that 1.65g phenol, 11g ethyl alcohol, 9.9g 30wt% hydrogen peroxide and 16.5mg benzene are added into 30ml glass reaction bottle
Selenic acid, under magnetic stirring warming-in-water to 60 DEG C insulation reaction 2 hours.It is down to room temperature, obtains 21.5g oxidation solution, sampling point
Oxidation solution composition is analysed, wherein phenol 4.97%, 1,4-benzoquinone 2.58%, as a result phenol conversion 35.24%, 1,4-benzoquinone are selective
83.03%.
Embodiment 2
1.8g phenol, 10g acetonitrile, 10g 25wt% hydrogen peroxide and 12mg diphenyl two are added into 30ml glass reaction bottle
Selenide, under magnetic stirring warming-in-water to 70 DEG C insulation reaction 1.5 hours.It is down to room temperature, obtains 20.4g oxidation solution, is sampled
Oxidation solution composition is analyzed, wherein phenol 5.16%, 1,4-benzoquinone 3.59%, as a result phenol conversion 41.52%, 1,4-benzoquinone are selective
85.29%.
Embodiment 3
1.75g phenol, bis- fourth of 9.6g methanol, 8.4g 35wt% hydrogen peroxide and 11mg are added into 30ml glass reaction bottle
Base diselenide, under magnetic stirring warming-in-water to 65 DEG C insulation reaction 2 hours.It is down to room temperature, 18.2g oxidation solution is obtained, takes
Sample analyzes oxidation solution composition, wherein phenol 5.57%, 1,4-benzoquinone 3.91%, as a result phenol conversion 42.07%, 1,4-benzoquinone selection
Property 84.12%.
Embodiment 4
Into 30ml glass reaction bottle be added 1.75g phenol, 10.1g dichloroethanes, 9.6g 30wt% hydrogen peroxide and
8.5mg Polymer-supported type selenium catalyst, under magnetic stirring warming-in-water to 55 DEG C insulation reaction 2.5 hours.Room temperature is down to,
Catalyst is filtered out, 18.8g oxidation solution is obtained, sampling analysis oxidation solution forms, wherein phenol 5.69%, 1,4-benzoquinone 3.84%,
As a result phenol conversion 38.87%, 1,4-benzoquinone selectivity 92.36%.
Embodiment 5-8
On the basis of embodiment 4, recycled is carried out to Polymer-supported type selenium catalyst, the result is as follows:
| Embodiment | Catalyst applies batch | Phenol conversion/% | 1,4-benzoquinone selectivity/% |
| 4 | It is new to throw | 38.87 | 92.36 |
| 5 | Set 1 | 40.05 | 91.68 |
| 6 | Set 2 | 39.42 | 92.31 |
| 7 | Set 3 | 38.57 | 90.58 |
| 8 | Set 4 | 39.48 | 91.27 |
Embodiment 9-12
On the basis of embodiment 1, it uses different selenium catalyst instead, investigates catalytic effect, the result is as follows:
Claims (6)
1. a kind of Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium, which is characterized in that by phenol, solvent,
Selenium catalyst, hydrogen peroxide put into glass reaction bottle, react at a certain temperature, obtain the oxidation solution containing 1,4-benzoquinone, selenium catalysis
Dosage is the 0.5-5wt% of phenol quality；Phenol concentration is 1-40wt%；Hydrogen peroxide concentration is 10-70wt%；Hydrogen peroxide and benzene
The mole ratio of phenol is 0.1-7:1；Reaction temperature is 30-100 DEG C；Reaction time is 0.5-8 hours, and the selenium catalyst is
The selenium catalyst of small molecule selenium catalyst or Polymer-supported, the selenium catalyst of the Polymer-supported are loaded by polystyrene
Selenium catalyst, the small molecule selenium catalyst are benzene seleninic acid, diphenyl disenenide ether, two (p-methoxyphenyl) diselenides, two
Cyclohexyl diselenide, two (N, N- dimethylamino phenyl) diselenides, two (chlorphenyl) diselenides, dibutyl diselenide, it is described
Loaded by polystyrene selenium catalyst the preparation method comprises the following steps: under nitrogen protection, 4g polystyrene resin soaks in 30mL cyclohexene,
Then tetramethylethylenediamine 37.2mmol and n-BuLi 48mmol is added, stirring is warming up to 65-70 DEG C, reacts 4hr, it filters,
Filter cake is washed with 30mL THF, and filter cake is transferred in reaction flask, and 40ml THF is added, and is cooled to 0 DEG C, and dimethyl two is added
After stirring 20min, 3mL water is added in selenide 5mmol, and polymer gradually becomes yellow from brown, is filtered, filter cake successively use THF,
Then water, methanol washing obtain the first seleno resin of pure Polymer-supported in 65 DEG C of dry r for 24 hours under vacuum；
Under nitrogen protection, 4g first seleno resin soaks in 60ml chloroform, and the chloroformic solution of bromine, the chloroformic solution of bromine is then added
It is dissolved in 20mL chloroform for 6mmol bromine, at 0 DEG C, stirs 30min, filtering, filter cake is washed with dehydrated alcohol；Filter cake is transferred to
In reaction flask, 60ml dehydrated alcohol is added, 2hr is reacted at 70 DEG C, material gradually becomes red, and filtering, filter cake is successively used
Then ethyl alcohol and methylene chloride washing obtain the selenium bromide tree of the pure Polymer-supported of 4.25g in 65 DEG C of dry r for 24 hours under vacuum
Rouge；
Under nitrogen protection, 0.7143g selenium bromide resin soaks in 60ml chloroform, and 10 equivalent 30wt% dioxygens are added at 0 DEG C
Water stirs 2hr at room temperature, and material gradually becomes white, filtering, and filter cake is successively washed with ethyl alcohol and methylene chloride, then very
In 65 DEG C of dry r for 24 hours under sky, pure loaded by polystyrene selenium catalyst is obtained.
2. one kind Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium according to claim 1, special
Sign is that selenium catalytic amount is the 3wt% of phenol quality；Phenol concentration is 5-20wt%；Hydrogen peroxide concentration is 25-50wt%；
The mole ratio of hydrogen peroxide and phenol is 0.2-5:1；Reaction temperature is 40-90 DEG C；Reaction time is 1-5 hours.
3. one kind Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium according to claim 1, special
Sign is that the solvent is alcohols, organic nitrile, halogenated hydrocarbon solvent.
4. one kind Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium according to claim 3, special
Sign is that the solvent is methanol, ethyl alcohol, isopropanol, n-butanol, dichloroethanes, trichloroethanes, acetonitrile.
5. one kind Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium according to claim 1, special
Sign is that the mass ratio of solvent and phenol is 2.5-50:1.
6. one kind Phenol by Hydrogen Peroxide oxidative synthesis 1,4-benzoquinone method of catalyst containing selenium according to claim 5, special
Sign is that the mass ratio of solvent and phenol is 5-15:1.
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| CN110102345B (en) * | 2019-05-15 | 2021-09-10 | 扬州大学 | Synthetic method of selenium-containing copolymer catalyst for catalyzing olefin oxidative cracking |
| CN110229053A (en) * | 2019-07-08 | 2019-09-13 | 邵阳学院 | A kind of preparation method of 1,4-benzoquinone |
| CN110183318A (en) * | 2019-07-08 | 2019-08-30 | 邵阳学院 | A kind of preparation method of chloranil |
| CN112275319B (en) * | 2020-11-03 | 2023-06-06 | 扬州工业职业技术学院 | Organic selenium catalyst loaded with carbon nano tubes and preparation method and application thereof |
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Non-Patent Citations (2)
| Title |
|---|
| Polystyrene-Bound Phenylseleninic Acid: Catalytic Oxidations of Olefins,Ketones, and Aromatic Systems;Richard T. Taylor等;《J. Org. Chem.》;19831231;第48卷(第26期);第5160-5164页 |
| 硒钼杂多配合物及其稀土盐的合成及催化苯酚羟化反应的研究;张平宇等;《中国稀土学报》;20060430;第24卷(第2期);第244-246页 |
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