JP2732906B2 - Method for producing quinones - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention oxidizes phenols with molecular oxygen,
The present invention relates to a method for producing a corresponding quinone. The corresponding hydroquinones can be produced by hydrogenating the quinones. Among them, unsubstituted hydroquinone is a useful compound used in the photographic industry.

[Conventional technology]

A method for producing parabenzoquinones (hereinafter abbreviated as quinones) by reacting phenols with oxygen in the presence of copper chloride is known (for example, JP-A-62-14844).
6).

However, when the reaction is carried out using copper chloride as a catalyst, the material of the apparatus is significantly corroded, and almost all metallic materials are not practical.

[Problems to be solved by the invention]

An object of the present invention is to solve the problem of corrosion of metal materials using a novel catalyst.

[Means for solving the problem]

That is, the present invention is a method for producing quinones, which comprises reacting phenol or substituted phenol with oxygen in the presence of copper and boron oxides.

The oxides of copper and boron used in the present invention are substances containing cuprous oxide or cupric oxide and boron oxide,
The substance may include water of hydration and water of adsorption. The atomic ratio of boron to copper is from 0.01 to boron per gram atom of copper.
100 gram atoms.

Although there are various methods for producing this substance, cuprous oxide or cuprous hydroxide, cupric oxide or cupric hydroxide, and boron oxide or a hydrate thereof (for example, metaboric acid, Boric acid, tetraboric acid, etc.).

At this time, it is preferable that boron oxide or a hydrate thereof is dissolved in hot water, mixed with a copper compound, and dried.

There is also a method in which the dried substance is fired at 150 to 1000 ° C. to produce the dried substance.

There is also a method of coprecipitation in an aqueous solution containing both elements. For example, it can be produced by mixing an aqueous solution of a soluble copper salt and an aqueous solution of borax to precipitate copper borate, filtering this, and drying.

Further, an oxide of copper and boron supported on a carrier can also be used in the method of the present invention. As a carrier,
Activated carbon, activated alumina, silica, silica-alumina, diatomaceous earth, titania, zirconia, acid clay, activated clay, bauxite, magnesia and the like are used. The loading method is not limited, but an impregnation method or a coprecipitation method can also be used.

The amount of the oxides of copper and boron used as a catalyst is such that a catalyst containing 0.001 to 10 g atoms of copper per mole of phenol or substituted phenol is used when the reaction is carried out in a batch system. When the amount is less than 0.001 g atom, the reaction rate is low, and when the amount is 10 g atom, the reaction rate is sufficient and no additional addition is required. When using the fixed bed circulation method, usually 0.01 to 100 g
(Phenols + solvent) / (g catalyst · hr).

The phenol or substituted phenol used in the present invention is represented by the general formula (I) (Wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and include hydrogen, halogen, cyano, alkyl or alkoxy containing 1 to 12 carbon atoms, 6 to 16
Represents an unsubstituted or substituted phenyl or an unsubstituted or substituted phenoxy group containing 2 carbon atoms), and particularly as R ₁ , R ₂ , R ₃ and R ₄ , hydrogen, fluorine, chlorine, bromine, Examples include iodine, cyano, methyl, ethyl, propyl, butyl, pentyl, methoxy, ethoxy, phenyl, phenoxy and the like. Preferred phenols used in the present invention include phenol, i.e., unsubstituted phenol, o-chlorophenol, 2,6-dichlorophenol, o-cresol, m-cresol, 2-tert-butylphenol, and 2,6-dimethyl. Phenol, 2,3-dimethylphenol, 2,6-ditertiary butylphenol, 2,3,5
-Trimethylphenol, 2,3,6-trimethylphenol, o-phenylphenol, o-benzylphenol and the like.

Although the method of the present invention can be carried out without a solvent, a solvent can also be used. Examples of the solvent include water, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol; nitriles such as acetonitrile and benzonitrile; amides such as dimethylformamide, dimethylacetamide, diethylformamide and diethylacetamide; ethylene glycol and diethylene glycol. Glycols such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethers such as diethylene glycol dimethyl ether, acetone, acetic acid, sulfolane, dimethylimidaridinone, N
-Methylpyrrolidone, tetraglyme, dimethylsulfoxide, tributylphosphine oxide, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol and the like can be used. When a solvent is used, the concentration of the phenol is usually 1% by weight or more based on the reaction solution. Below 1 wt%, the volumetric efficiency of the reactor is poor.

As the solvent, methyl alcohol, ethyl alcohol,
Alcohols such as propyl alcohol, nitriles such as acetonitrile, and amides such as dimethylacetamide and diethylacetamide are preferred.

As the oxygen source, oxygen diluted with air or nitrogen can be used in addition to pure oxygen.

The reaction pressure may be normal pressure, and if desired, may be either pressurization or reduced pressure.

Usually, the pressure of oxygen is 0.1-500 kg / cm ² G. The higher the oxygen pressure, the greater the rate of oxidation of phenols,
In addition, the selectivity to the corresponding quinones increases. Substituted phenols substituted with alkyl or alkoxy groups than unsubstituted phenols have a faster oxidation rate at the same oxygen pressure and a higher selectivity to the corresponding quinones. Therefore, lower oxygen pressures can be used.

20 kg / cm ² G as oxygen pressure for unsubstituted phenol
The above is preferable, and the oxygen pressure is preferably 200 kg / cm ² G or less in consideration of production equipment cost.

The reaction temperature depends on the phenol used,
Usually, it is 0 to 150 ° C, preferably 10 to 100 ° C. A substituted phenol substituted with an alkyl or alkoxy group has a higher reaction rate than an unsubstituted phenol, and can be reacted at a lower temperature.

The reaction time is usually about 0.5 to 10 hours in the case of a batch system. Separation of the product from the catalyst can be easily performed by filtration. For example, benzoquinone can be obtained from the product by steam distillation or crystallization.

〔Example〕

Example 1 Production of Catalyst 20 g of borax was dissolved in 500 g of distilled water. A solution obtained by dissolving 3.65 g of anhydrous copper sulfate in 100 g of distilled water was dropped into this, and a precipitate was formed.

This precipitate was washed with a small amount of water and then dried at 120 ° C. for 3 hours to obtain 2.92 g of a catalyst.

Synthesis of Benzoquinone 20 g of methyl alcohol, 0.941 g (0.01 mol) of phenol and 1.0 g of catalyst were charged into a 70 cc stainless steel autoclave. Autoclave with nitrogen 20kg / cm ²
Pressurized to G, then add oxygen gas and total pressure 100kg / cm ² G
I made it.

The autoclave was raised to 70 ° C. and kept at that temperature for 3 hours. Thereafter, the autoclave was cooled to room temperature, depressurized, and the contents were taken out and analyzed.

Phenol conversion rate 24.0% Selectivity to parabenzoquinone 85.6% Comparative Example 1 Production of catalyst 4.91 g of anhydrous copper sulfate was dissolved in 87 g of distilled water. A 0.615N aqueous solution of caustic soda was dropped into the mixture to adjust the pH to 8. The precipitate is filtered off, washed with a little water, then with methyl alcohol, dried in air for 48 hours, and charged with copper hydroxide catalyst 3.83.
g was obtained.

Synthesis of benzoquinone In place of the copper borate catalyst of Example 1, 1 g of copper hydroxide catalyst
The reaction was carried out under the same conditions as in Example 1 except for the above.

 The yield of parabenzoquinone was 0.5%.

〔The invention's effect〕

With cupric hydroxide containing no oxide of boron, only 0.5% of parabenzoquinone is produced, but with the catalyst containing oxides of copper and boron as shown in Example 1, 20.5%
% (24.0 × 0.856) of parabenzoquinone is produced.

Further, with the catalyst containing the oxides of copper and boron, stainless copper is not corroded at all.

Claims (1)

(57) [Claims] 1. A method for producing quinones, comprising reacting phenol or a substituted phenol with oxygen in the presence of copper and boron oxides.