JPS6337781B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing benzophenoneazines (hereinafter referred to as azines) from benzophenone imines (hereinafter referred to as imines).

Azines are extremely useful substances used as intermediates in hydrazine synthesis reactions using benzophenones as starting materials. As a method for producing azines by oxidizing imines, a method using molecular oxygen in the presence of cuprous chloride is known (USP 2870206). However, this method
Since an expensive copper salt catalyst is used as the liquid-phase homogeneous catalyst, complicated steps such as separation, recovery, and regeneration of the catalyst are required, resulting in increased equipment costs and energy loss. Furthermore, due to the problem of corrosion caused by halogen substances, expensive materials are required, and this method cannot be said to be industrially advantageous.

The present invention has been made as a result of investigating various methods for industrially producing azines by eliminating the above-mentioned drawbacks.The present invention has revealed that metal oxides are useful substances as oxidizing agents for producing azines from imines. I discovered something and completed it based on this.

That is, the present invention is based on the general formula (The substituents R ¹ and R ² in the formula may be the same or different, and may include a chain, cycloaliphatic or aromatic hydrocarbon group having 1 to 10 carbon atoms, an ether group thereof, an acyl group, A group selected from the group consisting of acyloxy group, alkoxycarbonyl group, halogen, hydroxy, nitro, amido, cyano, and disubstituted amino group, or R ¹ and R ² together represent a single bond or group. (m and n are 0 or integers of 1 to 5.) By oxidizing the benzophenone imine represented by the general formula (In the formula, the substituents R ¹ R ² and mn are the same as in the general formula ()) In the method for producing benzophenoneazines, the oxidizing agent is oxidation of a metal selected from nickel, thallium, lead and silver. This is a method for producing benzophenoneazines, which is characterized by using a benzophenone azine.

The imines of the present invention are those represented by the above general formula, and specific examples include benzophenone imine, 2-, 3- or 4-methylbenzophenone imine, 2-, 3- or 4-ethylbenzophenonimine, 2-, 3- or 4-butylbenzophenonimine, 2-, 3- or 4-amylbenzophenonimine, 2-, 3- or 4-decylbenzophenonimine, 2-, 3- or 4-methoxybenzophenonimine, 4-cyclohexylbenzophenonimine, 4-phenylbenzophenonimine, 2,4-dimethylbenzophenonimine, 2-methyl-4-ethylbenzophene Nonimine, 2-methyl-4-butylbenzophenonimine, 2,2'- or 4,4'-dimethylbenzophenonimine, 2- or 4-chlorobenzophenonimine, 2-chloro-4-methyl Benzophenone imine, 4-nitrobenzophenone imine, 2,
4-Dinitrobenzophenonimine, 4-hydroxybenzophenonimine, 4-N,N'-dimethylcarbamoylbenzophenonimine, 4-cyanobenzophenonimine, fluorenoneimine, 4-acetylbenzophenonimine, 4 -acetoxybenzophenone imine, 4-methoxycarbonylbenzophenone imine, 4-N,N-dimethylbenzophenone imine, and the like.

In the present invention, it is usually preferable to use an imination reaction solution of benzophenones as the imine. In this case, unreacted benzophenones act as a solvent, so it is not necessary to add a solvent, but the azine produced by the reaction Solvents can also be added to help dissolve the compounds and keep the reaction system in solution. The solvent is preferably a solvent that is difficult to oxidize in the oxidation reaction of imines and helps dissolve the product azine, and is particularly immiscible with water and has low viscosity, such as benzene, toluene, xylene, mesitylene, etc. , chlorobenzene,
Dichlorobenzene, nitrobenzene, dinitrobenzene, diphenyl, phenanthrene, anisole, diphenyl ether, acetophenone, benzyl, fluorenone, benzonitrile, hexane, heptane, cyclohexane, cyclooctane, ethylene dichloride, tetrachlorethylene, diisopropyl ether, dipropyl ether , diisobutyl ketone, butyl acetate, phenyl benzoate, dimethyl phthalate, etc.

The metal oxide used as an oxidizing agent in the present invention is an oxide of a metal selected from nickel, thallium, lead, and silver. Specific examples include nickel monoxide, trinickel tetroxide, dinickel trioxide, and Nickel oxide, silver monoxide, disilver monoxide, dithallium trioxide, dithallium monoxide, lead monoxide,
Examples include trilead tetroxide and lead dioxide.

The oxidizing agents of the present invention can be prepared in a variety of ways for increased activity and selectivity. In the case of a single-component metal oxide, the metal of the metal,
Calcinate hydroxides, carbonates, nitrates, halides, nitrites, organic acid salts such as formates, acetates, oxalates, etc., or combine them with oxidizing agents such as hydrogen peroxide, peracetic acid, oxygen, air. , ozone, sodium hypochlorite, potassium hypochlorite, sodium peroxide, barium peroxide, performic acid, permaleic acid, benzoyl peroxide, MEK peroxide,
Obtained by reaction with pertoluic acid, chlorine, nitric acid, aqua regia, etc. In the case of multi-component metal oxides, multi-component metals obtained by coprecipitation method, kneading method, etc.
It can be obtained by calcining hydroxides, carbonates, etc. or by reacting them with oxidizing agents.

It can also be used by being supported on a carrier for the purpose of preventing sintering of the oxidizing agent, improving selectivity, etc. The carrier may be any carrier as long as it is stable under the reaction conditions and does not inhibit the reaction, such as activated carbon, asbestos, diatomaceous earth, caustic magnesia, silica gel, silicon carbide, celite, alumina, silica alumina, which are commonly used as carriers.
Alumina magnesia, titanium oxide (rutile), etc. can be used. General methods such as ion exchange, impregnation, coprecipitation, and kneading are used to support single-component and multi-component oxidants on carriers. , used as a carrier-supported metal oxide in the aforementioned method.

The oxidizing agent of the present invention usually tends to exhibit higher oxidizing power as the metal compound is in a higher oxidation state, but of course it has oxidizing power even in a lower oxidation state and can be used. Furthermore, it does not need to be a pure metal oxide,
Those that produce metal oxides in the reaction system, or hydroxides, halides, sulfides, phosphides, carbonates, nitrates, silicates, borates, sulfates, phosphates, and formates of these metals , oxalate, acetate, and the like.

The oxidizing agent in the present invention is in various forms,
For example, the oxidizing agent can be used in particulate, powder, fibrous, spongy, or other forms, and the form of the oxidizing agent may be appropriately selected depending on the reaction type. For example, if the oxidizing agent is prepared in granular form, a fixed bed is usually preferable, although it depends on the shape, specific gravity, size, etc. of the granules, and if it is in powder form, it is used by dispersing it in the reaction liquid phase under stirring. It is best to use a method or a fluidized bed method. As for the amount of the oxidizing agent used, it is usually preferable to use an amount greater than the theoretical amount necessary for the desired imine conversion rate.

After the oxidizing agent used in the present invention oxidizes the imine, it is naturally reduced to a metal oxide and/or metal in a lower oxidation state. Therefore, it can be reused by regenerating it with the following regenerating agent. For example, hydrogen peroxide, peracetic acid, oxygen, ozone, sodium hypochlorite,
Potassium hypochlorite, sodium peroxide, barium peroxide, performic acid, permaleic acid, benzoyl peroxide, MEK peroxide, pertoluic acid,
These include chlorine, nitric acid, and aqua regia.

The reaction conditions for the oxidation reaction of the present invention cannot be uniformly defined depending on the active reaction type of the oxidizing agent, etc., but the reaction temperature is 60 to 300°C, preferably 70 to 250°C,
More preferably, the temperature is 100°C to 230°C.

The reaction time is influenced by the activity of the oxidizing agent, the desired imine conversion rate, etc., but is usually in the range of 0.01 to several tens of hours. The atmosphere within the reaction system is not particularly limited, and may be, for example, an atmosphere of air, oxygen gas, nitrogen gas, or the like. In the oxidation reaction of the present invention, it is necessary to suppress the hydrolysis of imines by reaction product water, and therefore it is preferable to introduce air, oxygen gas, nitrogen gas, etc. into the reaction system by blowing and circulating. , it is preferable that the gas be further dried. The scope of the present invention also includes a method of producing azines in one step by simultaneously adding ammonia and an oxidizing agent to benzophenones.

According to the present invention, since imines can be oxidized even when the inside of the reaction system is in an inert gas atmosphere such as nitrogen gas, dangers such as explosion can be prevented. In addition, since it is a heterogeneous oxidizing agent, it can be recovered and reused by simple operations and then reoxidized, making it an industrially extremely advantageous method for producing azines. .

Example 1 20 g (imine 2.67 x 10 ^-2 mol) of benzophenone imine (purity 24.2%, remainder benzophenone) was charged into a reactor, and heated while nitrogen was flowing through a blow port inserted into the bottom of the reactor. , when the temperature reaches 180℃, the oxidizing agent powder disilver monoxide 3.08
g (1.33×10 ^-2 mol) is added. After stirring for 1 hour, the reaction solution was analyzed by gas chromatography, and the yield of benzophenone azine was 65.2%.
(0.87×10 ^-2 mol). The separately recovered oxidizing agent was regenerated at 300°C in an atmosphere of 15 atm oxygen, and benzophenone imine was oxidized under the same conditions as described above, and similar results were obtained.

Example 2 3.18g of powdered lead dioxide (1.33×10 ^-2
Exactly the same procedure as in Example 1 was carried out except that mol) was used. Reaction was carried out for 3 hours, yield 73.2%
(0.98×10 ^-2 mol) to produce benzophenone azine.

Example 3 The same procedure as in Example 2 was performed except that the reaction temperature was 140°C. The reaction was carried out for 2 hours and the yield was
38.4% (0.15×10 ^-2 mol) of benzophenone azine was produced.

Example 4 3.06g of powdered dithallium trioxide as an oxidizing agent
(0.67×10 ^-2 mol) and the reaction temperature was 200℃.
Exactly the same operation as in Example 1 was performed except for the following. The reaction was carried out for 1 hour, yield 64.0% (0.85×
10 ^-2 mol) to produce benzophenone azine. The separately recovered oxidizing agent was regenerated at 160°C in an atmosphere of 1 atm air, and benzophenone imine was oxidized under the same conditions as described above, and similar results were obtained.

Example 5 20 g of benzophenone imine (purity 24.2%, the rest being benzophenone) (imine 2.67 x 10 ^-2 mol) and powdered silver monoxide 3.08 g (1.33 x 10 ^-2 mol) were inserted to the bottom of the reactor. The mixture was charged into a reactor while flowing nitrogen through the inlet, heated while stirring, and after reaching 180°C, was reacted for 1 hour. When the reaction solution was analyzed by gas chromatography,
Yield of benzophenone azine 80.5% (1.07×10 ^-2
moles).

Example 6 The same procedure as in Example 5 was carried out except that 6.0 g of powdered nickel peroxide was used as the oxidizing agent.
The reaction was carried out for 1 hour, and benzophenone azine was produced in a yield of 30.0% (0.40×10 ⁻² mol).

Claims (1)

[Claims] 1. General formula (The substituents R ¹ and R ² in the formula may be the same or different, and may include a chain, cycloaliphatic or aromatic hydrocarbon group having 1 to 10 carbon atoms, an ether group thereof, an acyl group, A group selected from the group consisting of acyloxy group, alkoxycarbonyl group, halogen, hydroxy, nitro, amido, cyano, and disubstituted amino group, or R ¹ and R ² together represent a single bond or group. m and n are 0 or integers of 1 to 5.) By oxidizing the benzophenone imine represented by the general formula (In the formula, substituents R ¹ , R ² and m, n are the same as in the general formula ()) In the method for producing benzophenoneazines, the oxidizing agent is selected from nickel, thallium, lead and silver. A method for producing benzophenoneazines, characterized by using a metal oxide.