CN104292096A - Method for preparing p-benzoquinone compound through selective catalytic oxidation of phenol compound - Google Patents

Abstract

The invention provides a method for preparing p-benzoquinone compound by selective catalytic oxidation of phenol compound. A method for preparing p-benzoquinone compounds with high selectivity under mild conditions under the action of molecular cocatalysts.

Description

A kind of method that selective catalytic oxidation phenol compound prepares p-benzoquinone compound

the

Cross References to Related Applications

The applications are entitled "A Preparation Method for P-Benzoquinone Compounds" (Application No.: 201410443854.7, submitted on September 3, 2014) and "A Method for Preparing P-Benzoquinone Compounds by Direct Oxidation of Phenol Compounds" (Application No. No.: 201410449008.6, submitted on September 5, 2014), the extension and supplement of the Chinese patent, and the former has priority over the latter.

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technical field

The invention relates to a method for selectively catalytically oxidizing phenol compounds to prepare p-benzoquinone compounds, in particular to a catalyst capable of highly selectively catalyzing phenol compounds to prepare p-benzoquinone compounds in an oxygen-containing atmosphere. the

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Background technique

P-benzoquinone compounds are important raw materials, intermediates and auxiliary agents for the synthesis of pesticides, dyes, rubber, plastics, and fine chemicals. They are mainly used in developers, dyes, rubber antioxidants, polymer monomer polymerization inhibitors, and antioxidants. Related areas. the

Due to the importance of p-benzoquinone compounds, various synthetic routes have been developed successively. The aniline oxidation method is the earliest process to achieve industrialization, that is, aniline is oxidized into p-benzoquinone by manganese dioxide and other high-valent metal salts in sulfuric acid medium, and then separated by steam stripping to obtain p-benzoquinone products. However, the raw material cost of this process is too high, and there are serious pollution problems. the

As a possible alternative process, the preparation of p-benzoquinone by oxidation of phenol with oxygen was developed. For example: the article (Two-step Process for Preparation of Hydroquinone by Catalytic Oxidation of Phenol, Hu Yucai et al., Chemical Reaction Engineering and Technology, 2006, 22 (6): 544-548) reported the use of copper nitrate and sodium nitrate (molar ratio = 1:3) As a catalyst, phenol can be oxidized to p-benzoquinone under the condition that the mass ratio of catalyst to phenol is 1:2; the article (Oxygen direct catalytic oxidation of phenol to synthesize p-benzoquinone, Song Wei et al., Fine Petrochemical Industry, 2008 , 25(3):55-58) reported the oxidation of phenol to p-benzene using copper chloride and lithium chloride (molar ratio = 1:3) as a catalyst under the condition that the mass ratio of catalyst to phenol was 1:2. quinone. CN102336643A and CN102351656B also disclose similar technologies. However, the above method requires almost stoichiometric catalyst, and the amount of catalyst used is too large. the

CN1918101A discloses a method for preparing benzoquinone and hydroquinone, the molar equivalent of copper-containing catalyst and phenolic compound is not more than 0.1, and benzoquinone is synthesized under the action of alkane nitrile, aromatic nitrile or organic amide accelerator class of compounds. However, this technical route adds an accelerator to the solvent. the

Therefore, it is an urgent need in this field to develop a method for catalytic oxidation of p-benzoquinone compounds with lower cost. the

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Contents of the invention

The present invention hereby discloses a method for preparing p-benzoquinone compound by selective catalytic oxidation of phenol compound, the method comprising: adding the phenol compound into a liquid medium, in the presence of catalytically metered transition metal compound main catalyst and star molecular co-catalyst , a process for preparing p-benzoquinone compounds with high selectivity using oxygen or oxygen-containing gas as an oxidizing agent. the

The phenol compound used in the present invention has the following structural formula:

Wherein R ₁ , R ₂ , R ₃ and R ₄ are independently selected from hydrogen, hydrocarbyl groups, the four may be the same or different, wherein the hydrocarbyl groups are selected from straight-chain or branched alkanes containing 1 to about 8 carbon atoms radicals, straight or branched chain alkoxy groups containing 1 to about 8 carbon atoms, alkene or aromatic groups containing about 6 to about 12 carbon atoms. Preferably, the alkyl group is an alkyl group containing 1 to 4 carbon atoms, the alkoxy group is an alkoxy group containing 1 to 4 carbon atoms, and the aromatic group is a phenyl group or a naphthyl group containing 6 to 12 carbon atoms. or biphenyl. More preferably, the phenolic compound can be phenol, α-naphthol, 2 (3 or 5 or 6)-methyl (ethyl, isopropyl or tert-butyl) phenol, 2-phenylphenol, 2-benzyl Phenol, 2-vinylphenol, 2,6(2,3, 2,5 or 3,5)-dimethyl(ethyl, isopropyl or tert-butyl)phenol, 2,3,5(2, 3,6, 2,5,6 or 3,5,6)-trimethyl(ethyl, isopropyl or tert-butyl)phenol, 2,3,4,5-tetramethylphenol or the aforementioned phenolic compounds mixture.

The transition metal compound procatalyst of the present invention is selected from one or more combinations of V, Mn, Fe, Co, Ni, Cu, Rh, Ce, Ag, Pt, Pd, and can be a metal halide, Sulfates, (nitrites), (halogenated) fatty acid salts, (halogenated) aromatic salts, succinates, Schiff base complexes, phthalocyanine complexes. Preferably, a suitable transition metal compound can be selected from one or a combination of V, Mn, Fe, Co, Ce, Cu, Ag, and the anhydrous or hydrated form of the transition metal compound can be used as a catalyst. the

The star-shaped molecular co-catalyst of the present invention can be represented by the following structural formula:

Wherein R is independently selected from heteroatom-containing aromatic rings, C, P, Si, N, and the heteroatom-containing aromatic rings can be pyridyl, pyrrolyl, indolyl, isoquinolyl, quinolinyl , R ₁ , R ₂ and R ₃ are independently selected from hydrogen and hydrocarbyl groups, and at least one of them is a hydrocarbyl group, and the three may be the same or different, and the hydrocarbyl groups may contain 6 to about 16 carbon atoms ( substituted) aromatic groups or (substituted) alkylaromatic groups, heteroatom-containing aromatic groups containing about 4 to about 14 carbon atoms or (substituted) straight chain or Branched chain alkane groups. Further, the (substituted) aromatic group or (substituted) alkylaromatic group is selected from groups containing 6 to 10 carbon atoms, and the heteroatom-containing (substituted) aromatic group contains 4 to 10 carbon atoms. A group of 10 carbon atoms, a (substituted) alkane group, a straight or branched chain group containing 1 to 8 carbon atoms. Preferred, but non-limiting examples include, the alkane group may be C ₁ -C ₈ straight or branched chain alkyl, the aromatic or alkylaromatic group may be phenyl, naphthyl, anthracenyl , biphenyl, benzyl, phenethyl, benzyl, (o/m/p) xylyl, (o/m/p) diethylphenyl, (o/m/p) trimethylphenyl, (o/m/p) triethylphenyl, heteroatom-containing aromatic ring can be pyrrolyl, indolyl, pyridyl, quinolinyl, isoquinolyl.

The reaction medium of the present invention is a liquid, which can be a halogenated alkane containing 1-3 carbon atoms, an alkane nitrile, an aromatic nitrile, a halogenated aromatic compound or an organic amide containing about 2 to about 8 carbon atoms, or A linear, branched or cyclic organic alcohol containing 1 to 8 carbon atoms, or a combination of the aforementioned solvents. the

In order to achieve the purpose of the above invention, the present invention adopts the following operation steps: after fully mixing the phenol compound, main catalyst, cocatalyst and solvent, add the high-pressure reactor, close the reaction device and fill it with oxygen-containing gas to reach the specified pressure. Cool down to room temperature after reacting for a certain period of time, exhaust and measure the amount of p-benzoquinone and unreacted phenol compound. Among them, the amount of catalyst, the molar ratio of main catalyst and co-catalyst, reaction temperature, reaction time and oxygen pressure all have important influence on the reaction result, and these factors are also the technical contents involved in the preparation method. the

Wherein, the molar ratio of the transition metal compound procatalyst used in the present invention to the phenol compound is 0.01-0.5, preferably, the molar ratio is 0.01-0.2. Further, the molar ratio of the star molecule co-catalyst to the transition metal compound main catalyst used in the present invention is 10-0.1, preferably, the molar ratio is 2-0.2. the

In the present invention, the mass ratio of the phenol compound to the solvent is reacted in the range of 1-30%. the

One of the characteristics of the present invention is mild reaction conditions, the reaction temperature used in the present invention is usually 20-120 ^o C, preferably, the temperature is 30-80 ^oC .

The oxygen used in the present invention can be pure oxygen, or a mixed gas containing oxygen can be used, and the mixed gas can be nitrogen, argon, helium, neon, or a combination of the above gases. Further, when the reaction gas used in the present invention is pure oxygen, the pressure is usually 1-120 atm, preferably, the pressure is 1-80 atm. the

The reaction time used in the present invention is usually 10 minutes to 5 hours, preferably, the reaction time is 30 minutes to 3 hours. the

In addition, one of the characteristics of the method is that the selectivity to benzoquinone products is high, no other o-benzoquinone products are observed, and the specific catalytic ability of the catalyst is strong. the

The following reaction process takes place in the reactor:

Detailed ways

Below in conjunction with the examples, the specific implementation of the present invention will be further described in detail. The following examples will help to understand the present invention, but do not limit the technical solution of the present invention in any form. the

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Example 1:

Add cobalt nitrate hexahydrate (2.91g, 10.0mmol), triphenylphosphine (2.62g, 10mmol), phenol (9.4g, 100mmol) and DMF (94.0g, 100mL) into a 250mL reactor, mix well, and close The reactor was filled with 20atm oxygen, stirred and heated to 60 ^o C, cooled to room temperature after 1 hour of reaction, and the mixture was taken out after exhaust for analysis, and the remaining phenol: 7.4g, p-benzoquinone: 1.9g.

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Embodiment 2-8:

The cobalt nitrate hexahydrate in Example 1 is replaced with other transition metal compounds, and the impact on the results is shown in the following table: project Main catalyst (g, mmol) Phenol (g) p-Benzoquinone (g) 1. -- 9.3 0 2. Vanadium nitrate (1.82, 10) 8.3 0.6 3. Ferric chloride (1.62, 10) 8.6 0.6 4. Manganese acetate (1.73, 10) 5.7 3.4 5. Ruthenium trichloride (2.07, 10) 5.1 4.0 6. Cerium sulfate tetrahydrate (4.04, 10) 6.8 2.3 7. Palladium chloride (1.77, 10) 7.2 2.0

Examples 9-17:

The triphenylphosphine in Example 1 is replaced with different star compounds, and the impact on the results is shown in the following table: project Cocatalyst (g, mmol) Phenol (g) p-Benzoquinone (g) 1. -- 8.7 0.4 2. Triphenylamine (2.45, 10) 8.2 0.9 3. Triethylamine (1.01, 10) 8.5 0.6 4. Trioctylamine (3.53, 10) 8.6 0.5 5. Dibenzylamine (1.97, 10) 8.1 1.1 6. Chlorotrimethylsilane (1.08, 10) 8.3 0.6 7. Isopropylpyridine (1.21, 10) 6.2 2.5 8. Methylquinoline (1.4, 10) 6.5 2.5 9. Diphenyl-2-pyridylphosphine (2.63, 10) 7.6 1.6

Examples 18-23:

The phenol concentration in embodiment 1, catalyst molar ratio are changed, and the impact on reaction result is shown in the table below:

Examples 24-30:

The DMF among the embodiment 1 is replaced with other solvents, and the impact on reaction result is shown in the table below: project Solvent (g, mL) Phenol (g) p-Benzoquinone (g) 1. Dichloromethane (130.1, 100) 8.6 0.5 2. Acetonitrile (78.5, 100) 6.2 3.9 3. Benzonitrile (197.0, 100) 6.9 2.4 4. Chlorobenzene (110.3, 100) 8.8 0.4 5. Methanol (78.5, 100) 8.5 0.7 6. Isopropanol (77.8, 100) 7.9 1.3 7. Octanol (83, 100) 8.1 1.1

Examples 31-33:

The oxygen pressure and components in Example 1 are changed, and the impact on the reaction result is shown in the table below: project gas (atm) Phenol (g) p-Benzoquinone (g) 1. O ₂ (1) 9.3 0.1 2. O ₂ (120) 5.9 3.2 3. air (100) 7.9 2.2

Examples 34-36:

The temperature in Example 1 is changed, and the impact on the reaction result is shown in the table below: project temperature ( ^° C) Phenol (g) p-Benzoquinone (g) 1. 20 9.3 0.1 2. 80 6.9 2.3 3. 120 5.8 3.4

Examples 37-40:

The phenol in embodiment 1 is substituted with other phenol compounds, and reaction result is as shown in the table below:

Due to space limitation, the present invention does not describe all the examples one by one, but the technical solutions obtained by equivalent replacement or equivalent transformation of the key elements of the technology are within the protection scope of the present invention.

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Claims (10)

1. The present invention discloses a method for preparing p-benzoquinone compounds by selective catalytic oxidation of phenol compounds, which is characterized in that: in a liquid medium, with phenol compounds as raw materials, in the transition metal compound main catalyst and star molecular co-catalyst Under the action of oxygen or oxygen-containing gas as an oxidizing agent, the technology of preparing p-benzoquinone compounds with high selectivity. 2. method according to claim 1, described phenol compound has following structural formula: Wherein R ₁ , R ₂ , R ₃ and R ₄ are independently selected from hydrogen and hydrocarbon groups, and the four may be the same or different. 3. the method according to claim 1 and the description of claim 2, described phenol compound is selected from phenol, α-naphthol, 2 (3 or 5 or 6)-methyl (ethyl, isopropyl or tert-butyl)phenol, 2-phenylphenol, 2-benzylphenol, 2-vinylphenol, 2,6(2,3,2,5 or 3,5)-dimethyl(ethyl, isopropyl phenyl or tert-butyl)phenol, 2,3,5(2,3,6,2,5,6 or 3,5,6)-trimethyl(ethyl, isopropyl or tert-butyl)phenol, 2,3,4,5-Tetramethylphenol or mixtures of the above compounds. 4. method according to claim 1, described transition metal compound procatalyst is selected from one or more in V, Mn, Fe, Co, Ni, Cu, Rh, Ce, Ag, Pt, Pd Combination, can be metal halides, sulfates, (nitrites), (halogenated) fatty acid salts, (halogenated) aromatic salts, succinates, Schiff base complexes, phthalocyanine complexes Preferably, a suitable transition metal compound can be selected from one or more combinations of V, Mn, Fe, Co, Cu, Ce, Ag, and the anhydrous or hydrated form of the transition metal compound can be used as a catalyst. 5. method according to claim 1, described star-like molecule co-catalyst can be expressed with following structural formula: Wherein R is independently selected from C, P, Si, N or a heteroatom-containing aromatic ring, and the heteroatom-containing aromatic ring can be pyridyl, pyrrolyl, indolyl, isoquinolyl, quinolinyl , R ₁ , R ₂ and R ₃ are independently selected from hydrogen and hydrocarbyl groups, and at least one of them is a hydrocarbyl group, and the three may be the same or different, and the hydrocarbyl groups may contain 6 to about 16 carbon atoms ( substituted) aromatic groups or (substituted) alkylaromatic groups, heteroatom-containing aromatic groups containing about 4 to about 14 carbon atoms or (substituted) straight chain or Branched chain alkane group; further, the (substituted) aromatic group or (substituted) alkylaromatic group is selected from groups containing 6 to 10 carbon atoms, heteroatom-containing (substituted) aromatic A group is a group containing 4 to 10 carbon atoms, a (substituted) alkane group is a linear or branched group containing 1 to 8 carbon atoms; preferred, but non-limiting examples include, an alkane group can It is C ₁ -C ₈ straight chain or branched chain alkyl, aromatic group or alkyl aromatic group can be phenyl, naphthyl, anthracenyl, biphenyl, benzyl, phenethyl, benzyl Base, (o/m/p) xylyl, (o/m/p) diethylphenyl, (o/m/bias) tricresyl, (o/m/p) triethylphenyl, containing hetero The atomic aromatic ring can be pyridyl, pyrrolyl, indolyl, isoquinolyl, quinolinyl. 6. The method according to claim 1, characterized in that: the molar ratio of transition metal compound procatalyst to phenol compound is at 0.01-0.5, preferably, the molar ratio is at 0.01-0.2; The molar ratio of the metal compound main catalyst is 10-0.01, preferably, the molar ratio is 2-0.2. 7. the method according to claim 1, described reaction medium is liquid, can be the haloalkane that contains 1-3 carbon atom, the alkane nitrile that contains about 2 to about 8 carbon atoms, aromatic nitrile, halide Substituted aromatic compounds or organic amides, or straight-chain, branched-chain or cyclic organic alcohols containing 1 to 8 carbon atoms, or a combination of the aforementioned solvents. 8. method according to claim 1, described oxygen can be pure oxygen, also can use the mixed gas that contains oxygen, can be nitrogen, argon, helium, neon or above-mentioned gas as the gas of mixed component For the combination of gases, when the reaction gas is pure oxygen, the pressure is usually 1-120 atm, preferably, the pressure is 1-80 atm. 9. The method according to claim 1, the temperature of the reaction is usually at 20-120 ^° C, preferably, the temperature is 30-80 ^° C. 10. The method according to claim 1, one of the characteristics of the method is that the selectivity of the benzoquinone product is high, no other o-benzoquinone products are observed, and the specific catalytic ability of the catalyst is strong.