JPS6042166B2 - Method for recovering ammonia from benzophenone imines - Google Patents

Description

Detailed Description of the Invention The present invention provides a method for reacting benzophenone imines with water without decomposing the benzophenone azines in the benzophenone imine oxidation reaction solution (including benzophenone azines and unreacted benzophenone imines). The present invention relates to a method for recovering ammonia and benzophenones from benzophenone imines i.

Benzophenone imines are intermediates in the synthesis reaction of hydrazine salts from benzophenones and ammonia (benzophenone method), and the benzophenone method is as follows.

Benzophenone imines are synthesized by condensation of benzophenones and ammonia, and benzophenone azines are further synthesized by oxidizing benzophenone imines with molecular oxygen using dissolved copper as a catalyst.

When benzophenone azines react with acids, they produce the original benzophenones and hydrazine salts, which are themselves industrially useful and are also raw materials for the synthesis of hydrazine. For example, when sulfuric acid is used as the acid, it becomes hydrazine sulfate. The above reaction can be explained using a series of reaction equations when benzophenone is used as the benzophenone.

In addition to the reaction formulas (1), (2), and (3), the process for synthesizing hydrazine salts using benzophenones as a starting material requires that the copper catalyst used in the oxidation is expensive, and if copper is present, subsequent operations may be required. There may also be cases where a copper removal and recovery process is required because it may interfere with the process.

For a method for removing copper from oxidizing solutions, see U.S. Pat.
Examples include a method of extraction with aqueous ammonia as known in No. 0206, and a method of extraction with acid.

However, when an acid is used, unreacted imines remaining in the oxidizing solution are hydrolyzed to produce benzophenones and ammonium salts.

For example, when sulfuric acid is used as the acid, the following reaction (4) occurs. Therefore, when an acid is used for the purpose of extracting copper, not only copper but also ammonia salts resulting from unreacted imines are extracted into the aqueous layer at the same time.

On the other hand, when copper extraction is performed with ammonia, residual imine in the oxidizing solution is not decomposed, but since sulfuric acid is used in the next step of hydrolyzing azines, the same reaction as in (4) will occur. be. Even if the purpose is different, such as recovering copper or hydrolyzing azines, as long as an acid is used, imines will be hydrolyzed and ammonium salts will be produced.

Unless the ammonium salt thus produced is properly treated or disposed of, it will gradually accumulate in the aqueous layer and seriously impede the reaction and operation. Furthermore, considering that ammonia and acid, which correspond to imines, are consumed, it is said to be extremely disadvantageous industrially to leave a large amount of unreacted imine due to oxidation in the series of hydrazine salt synthesis processes mentioned above. I have no choice but to. Naturally, in order to avoid leaving benzophenone imines, it is possible to increase the oxidation reaction rate in (2).

In order to obtain a high reaction rate, it is generally necessary to increase the reaction temperature, lengthen the residence time, or increase the catalyst concentration. This leads to an increase in catalyst recovery costs. Furthermore, it is thought that the number of by-products in the reaction (2) will naturally increase. Considering that benzophenones are expensive chemicals, it goes without saying that suppressing by-products as much as possible is an important condition for realizing the processes (1) to (3). The oxidation reaction rate is usually 70-99%. As a result of repeated efforts to solve these problems, the unreacted benzophenone imine in the oxidation reaction solution was reacted with water,
They found a method to decompose the original benzophenones and ammonia and completed the present invention. The present invention is based on the general formula (however, in the above formula, R1 and R2 have 1 to 10 carbon atoms)
chain formula, cycloaliphatic or aromatic hydrocarbon groups, ether groups consisting of these hydrocarbon groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, disubstituted amino groups, as well as halogen groups, hydroxy groups, nitro groups, cyano groups. The same or different groups selected from the group consisting of groups, or R1 and R2 together may represent a single bond or ring.

Also, M... n is O or an integer of 1 to 5. ) is oxidized with molecular oxygen in the presence of a copper catalyst to produce benzophenoneazines,
The unreacted benzophenone imines remaining in this oxidizing solution are removed from elements belonging to Groups I to V of the periodic table and from Periods 2 to 5 (excluding phosphorus, nitrogen, and carbon).
A method for recovering ammonia from benzophenone imines is characterized by recovering ammonia by reacting with water in the presence of an oxide of an element selected from iron, tungsten, bismuth, cerium, thorium, and neodymium. The benzophenonimines used in the present invention are compounds represented by the following general formula.

(However, in the above formula, R1 and R2 have 1 to 10 carbon atoms.
chain formula, cycloaliphatic or aromatic hydrocarbon groups, ether groups consisting of these hydrocarbon groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, disubstituted amino groups, as well as halogen groups, hydroxy groups, nitrile groups, nitro groups, mutually the same or different groups selected from the group consisting of cyano groups, or R1 and R2 together may represent a single bond or ring. Also, M. ．． n is O or 1
It is an integer of ~5. ) Specific examples include benzphenonimine, 2-, 3-, or 4-methylbenzophenonimine, 2-, 3-, or 4-ethylbenzophenonimine, 2-, 3-, or 4-n- and /or IsO-
Propylbenzophenonimine, 2-, 3-, or 4-
n- and/or IsO- and/or tert-butylbenzophenonimine, 2-, 3-, or 4-amylbenzophenonimine, 2-, 3-, or 4-decylbenzophenonimine, 2-3-, or 4-methoxybenzophenone, 4-cyclohexylbenzophenone imine, 4
-Phenylbenzophenonimine, 2●4-dimethylbenzophenonimine, 2●3-dimethylbenzophenonimine, 3●4-dimethylbenzophenonimine, 2●
4-Diethylbenzophenonimine, 23-diethylbenzophenonimine, 3◆4-diethylbenzophenonimine, 2-methyl-4-ethylbenzophenonimine, 2-methyl-4-butylbenzophenonimine, 22
″-, 3・3″-, 4・4″-, 2・3″-, 24″-
, or 3,4″-dimethylbenzophenonimine, 2-
, 3-, or 4-chlorobenzophenonimine, 2-chloro-4-methylbenzophenonimine, 4-chloro-4''-methylbenzophenonimine, 4●4''-dichlorobenzophenonimine, 4-nitrobenzophenonimine, 2.4 -Dinitropenzophenone imine, 4-hydroxy. Benzophenone imine, 4-N-N-dimethylaminobenzophenone imine, 4-acetylbenzophenone imine, 4-methoxycarbonylbenzophenone imine, 4-N-N-dimethylcarbamoylbenzophenone imine, 4-cyanobenzofuquenon imine, fluorenone imine, xanthone Examples include imine, anthrone imine, and acridone imine.

Benzophenone imines are usually produced by condensation of benzophenones and ammonia, and the imination rate is usually
It is 20-50%. The oxidizing solution to be used in carrying out the present invention is one in which benzophenone imines are oxidized with molecular oxygen using dissolved copper as a catalyst, and contains benzophenone azines and unreacted benzophenone imines.

Specifically, for example, an oxidizing solution using copper halide, especially cuprous chloride as an oxidation catalyst (U.S. Patent No. 287020
No. 6), oxidizing solution using copper (■) halide methoxide (
JP 53-147047), copper acetate, copper thiocyanate,
Oxidizing solutions using copper cyanide, copper carbonate, copper sulfate, copper nitrate, and copper phosphate (Japanese Patent Publication No. 54-43490), as well as copper imine solutions and oxidation reaction solutions that use copper in forms that are completely different from these copper salts. A reaction solution in which imines are oxidized by dissolving them in (Patent Application No. 526/1982), or benzophenone is brought into contact with immonia and molecular oxygen in the presence of cuprous chloride,
Reaction solution for producing azines in one step (Japanese Patent Application Laid-open No. 52-794
No. 2), and furthermore, an oxidation reaction solution using a polymer catalyst in which a resin having a monodentate pyridine as a functional group is coordinated to cuprous halogenide (JP-A-52-131987).

The present invention can be carried out immediately after the oxidation reaction without pretreating the oxidation reaction solution. In the present invention, benzophenones act as a solvent, so no particular solvent is required. However, when decomposing imines at a lower temperature than the oxidation reaction, there is a risk that azines will precipitate. A solvent can also be added to help keep the reaction system in solution.

In particular, those that are thermally stable and have low viscosity are preferred. For example, benzene, toluene, 0-, m-, p-xylene, diethylbenzene, mesitylene, cumene, pseudocumene, amylbenzene, aromatic saturated hydrocarbons having 6 to 16 carbon atoms and mixtures thereof, chlorobenzene, o-, m- , p-dichlorobenzene, nitrobenzene, o-, m-, p-dinitrobenzene, o-, m-, p-chlorotoluenediphenyl, phenanthrene, anisole, diphenyl ether, acetophenone, benzyl, benzophenone,
Examples include hexane, heptane, cyclohexane, cyclooctane, ethylcyclohexane, ethylene dichloride, tetrachloroethylene, diisopropyl ether, dipropyl ether, diisobutyl ketone, butyl acetate, butyl benzoate, phenyl benzoate, dimethyl phthalate, and the like. Although there is no particular restriction on the concentration of unreacted benzophenone imines remaining in the oxidation reaction solution, it is not necessarily a good idea to leave a large amount of unreacted benzophenone imines in the oxidation reaction.

On the other hand, when the amount of benzophenone imine in the oxidation reaction solution is very small, recovering a small amount of ammonia by reacting it with water is not an advantageous method in terms of energy costs and equipment costs. That is, if the amount of the 4 benzophenone imines is small, the oxidation reaction is performed and the liquid is subjected to the next process (copper recovery or hydrolysis of benzophenone azine with acid).
You can send it as is. Therefore, the concentration of unreacted benzophenone imine in the oxidation reaction solution that can be carried out industrially advantageously is 0.2 to 15% by weight, more preferably 0.5 to 1% by weight.

When the benzophenonimines are decomposed with water, the catalyst used is an element belonging to Groups Ⅰ to Ⅲ of the periodic table and belonging to periods 2 to 5 (with the exception of phosphorus,
(excluding nitrogen and carbon), iron, tungsten, bismuth, cerium, thorium and neodymium.

These oxides can be used alone or in combination of two or more.

Furthermore, these oxides do not necessarily need to be highly pure. Therefore, the inclusion of other components that do not have the activity of decomposing imines is permissible as long as it does not impair the activity of these decomposition catalysts. Both natural products and synthetic products can be used as these oxides.

Specifically, boron trioxide, aluminum oxide, silicon oxide, scandium oxide, titanium oxide, vanadium pentoxide, gallium oxide, germanium oxide, diarsenic pentoxide, yttrium oxide, zirconium oxide, niobium oxide, indium oxide, second oxide Single component materials such as tin, antimony pentoxide, ferric oxide, tungsten oxide, bismuth oxide, cerium oxide, thorium oxide, two component materials such as silica alumina, silica zirconia, silica magnesia, silica poria, or natural Examples include clay materials such as acid clay, bentonite, kaolin, montmorinite, and synthetic zeolite. In addition, adding operations such as treating naturally occurring acid clay with acid to further increase its activity, or using ordinary zeolite in its acid form, are extremely effective methods for increasing catalytic activity. I can say that.

Among these oxides, aluminum oxide, silicon oxide, vanadium pentoxide, zirconium oxide, stannic oxide, antimony pentoxide, ferric oxide, tungsten oxide, thorium oxide, silica aluminum oxide, silica zirconia, zeolite, activated clay are preferred, particularly aluminum oxide, silicon oxide, stannic oxide, antimony pentoxide, ferric oxide, silica alumina, silica zirconia,
Zeolite and activated clay are preferred. There are no particular restrictions on the shape of these oxides, but a size of several microns or more is preferred from the standpoint of separation from the reaction solution.

It is appropriate to use a powdered product after dispersing it in the reaction solution. Further, it is appropriate to use a granular material in a fixed bed type. There are no particular restrictions on the amount of these oxides used, but
Generally, it is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, particularly preferably 0.01 to 10 parts by weight, particularly preferably 0.
6 to 2 parts of saliva. The reaction conditions in the present invention cannot be specified according to the activity of the imine decomposition catalyst, the reaction type, etc., but the reaction temperature is 60 to 350°C, preferably 80 to 300°C, and more preferably 100 to 2,700°C.
There is a C.

The reaction pressure is also not particularly limited. Although it can be carried out under increased pressure or reduced pressure, normal pressure to (to) atmospheric pressure is preferable. The reaction time varies depending on the activity of the catalyst, the concentration of unreacted imines in the oxidation reaction solution, the desired decomposition rate, etc., but is usually in the range of 0.1 to several tens of hours. There is no particular restriction on the reaction method in the present invention.

It can be carried out either batchwise or continuously. 5. Alternatively, it is also possible to perform the reaction in a batch format, continuously supplying only water to the reactor, and continuously extracting unreacted water and generated ammonia from the system in a gaseous state.

There is no particular restriction on the method of supplying water in the present invention.

It can be supplied to the reactor in a liquid state, or it can be heated in advance and sent to the reactor in a gaseous state. It is also possible to send water along with other glasses. In this case, nitrogen, argon, helium, air, etc. can be used as the glass that entrains water. However, inert gases such as nitrogen, argon, helium, etc. are preferred. In the present invention, there is no particular restriction on the amount of water supplied, but it is preferably 1 to 200 mol, more preferably 2 to 100 mol per mol of benzophenonimine to be decomposed.

In the present invention, it is desirable that ammonia generated by the decomposition of imines be continuously discharged from the system.

This ammonia is recovered as a liquid by cooling or pressurized cooling. If necessary, it can also be recovered by absorption in water. Benzophenones and six benzophenone azines are recovered. Example 1 Benzophenone imine (Benzophenone imine 23.
5%, the rest being benzophenone) 100q and commercially available cuprous chloride 0.39y (Kosou Kagaku Co., Ltd.) were mixed into a glass 20
The mixture was charged into a 0 ml reactor, and while maintaining the temperature at 140° C., pure oxygen was blown into the reactor at a rate of 500 TLLImin under normal pressure through an inlet inserted into the bottom of the reactor, and the mixture was stirred.

When the reaction solution was analyzed by gas chromatography, the yield of benzophenone azine was 87%, and the selectivity was 9.
It was generated at 9%.

The amount of unreacted benzophenonimine was 2.85%.
Next, powdered activated alumina (Nishio Kogyo Co., Ltd.) 4.0 μl was added to 100 fI of the above oxidation reaction solution as an imine decomposition catalyst.
Then, while keeping the oxidation reaction solution at 140°C, water was blown in as superheated steam at a rate of 8.6yIhr through a sparge ring (3 holes of 0.5φ) inserted into the bottom of the reaction vessel. Stir for hours.

After reacting for 1 hour, the reaction solution was analyzed by gas chromatography, and it was found that the benzophenone imine content had decreased to 0.31%.

Further, the generated ammonia was led out of the reactor, absorbed into water, and titrated with acid.

As a result, ammonia equivalent to 96% of the decomposed amount of imine was determined. Examples 2 to 25 In the same manner as in Example 1, oxidation of benzophenone imine and decomposition of unreacted benzophenone imine in the oxidizing solution with water were carried out using various commercially available powdered oxides.

In addition, unreacted benzophenone imine in the oxidizing solution is 2.9%.
It was within the range of The results are shown in Table 1.

Example 26 Benzophenonimine (Benzophenonimine 24.2
%, the remainder being benzophenone) and 1.0 q of commercially available cuprous chloride (Kosou Kagaku Co., Ltd.) in a 200 m glass tube.
The mixture was charged into a reactor No. 1, and while maintaining the temperature at 140° C., one pure oxygen was blown into the reactor at a rate of 500 mL/min under normal pressure through a blowing port inserted into the bottom of the reactor, and the mixture was stirred for 100 minutes.

After 10 minutes, the reaction solution was analyzed by gas chromatography, and it was found that benzophenone azine was produced in a yield of 87% and a selectivity of 96%.

The amount of unreacted pen2zophenone imine was 2.3%.
Next, 4.0 y of powdered activated alumina (Nishio Kogyo) was added as an imine decomposition catalyst to 100 y of the above oxidation reaction solution, and the imine was decomposed under the same conditions as in Example 1.

After 1 hour, benzophenone imine was 0.35%.

Examples 27 to 33 Oxidation of benzophenone imine and reaction in the oxidizing solution According to Example 26, decomposition of benzophenone imine with water was carried out using various commercially available powdered oxides.

Note that unreacted benzophenone imine in the oxidation reaction solution is 2.
It was 3%. The results are shown in Table 2. Example 34 Benzophenone imine solution (benzophenone imine 24.
0% and the remainder benzophenone) was charged into a reactor, and the reactor was heated and heated while blowing pure oxygen at a rate of 500 mtIm1n under normal pressure from a blowing port inserted into the bottom of the reactor.

When the temperature reached 160°C, 100 mg of commercially available copper formate (Kanto Kagaku Co., Ltd.) was added to the benzophenone imine solution.
The mixture was stirred at 0°C for 1 hour.

When the reaction solution was analyzed by gas chromatography,
Benzophenone azine was produced with a yield of 82% and a selectivity of 97%.

The amount of unreacted benzophenonimine was 3.71%.

Next, this oxidizing solution was maintained at 140° C., powdered silica gel (silica gel for chromatographs manufactured by Nishio Kogyo Co., Ltd.) 4y was added, and imine decomposition was carried out under the same conditions as in Example 1.

The imine content after the reaction was 0.15%.

Examples 35 to 41 According to Example 34, oxidation of benzophenone imine and decomposition of unreacted benzophenone imine in the oxidizing solution with water were carried out using various commercially available powdered oxides.

In addition, unreacted benzophenone imine in the oxidation reaction solution is 3.
It was 7%. The results are shown in Table 3. Example 42 Benzophenonimine (benzophenonimine 22.8
%, the rest being benzophenone) was charged into the reactor.
This was heated to 140°C.

Next, 2.0 g of commercially available metallic copper powder (Wako Pure Chemical Industries, Ltd.) was added, oxygen gas was flowed from the bottom of the reactor at a rate of 150 ml per minute, and the mixture was stirred under normal pressure for 3 hours. Subsequently, copper powder was filtered from the reaction solution using a glass filter (filter size G-4).

At this point, the bottom liquid was analyzed by gas chromatography, and as a result, benzophenone azine was produced in a yield of 90% and a selectivity of 97%. Unreacted benzophenone imine is 1.6
It was 5%. This Oki liquid was immediately transferred to another reactor and kept at 140°C while blowing dry nitrogen.

Next, 2.0 y of powdered activated clay (Mizusawa Chemical Co., Ltd.) was added as an imine decomposition catalyst, and water was turned into superheated steam from the gas injection pipe inserted into the bottom of the reactor for 6.1 y/hr.
The powder was blown in at a ratio of 3 times and stirred. Imine after reaction is 0
．． It was 20%. Example 43 Benzophenone imine solution (Benzophenone imine 46.
7%, remaining livenzophenine) 50yI:. o-dichlorobenzene (Kosou Chemical Co., Ltd.) 50y1 and cuprous chloride 1
．． 0y was charged into a reactor, and the mixture was stirred for 6 minutes while maintaining the temperature at 120° C. and blowing oxygen gas at a rate of 500 mL min from the bottom of the reactor.

Analysis of the reaction solution by gas chromatography revealed that benzophenone azine was produced in a yield of 87% and a selectivity of 99%.

The amount of unreacted imine was 2.83%. Next, powdered activated clay (Mizusawa Chemical Co., Ltd.) 4V was added to this oxidizing solution as an imine decomposition catalyst, water was blown into the bottom as superheated steam at a rate of 7.2 qIhr, and the mixture was stirred for 1 hour.

The amount of benzophenone imine after the reaction was 0.09%.

Example 44 Oxidized and unreacted imine was decomposed in exactly the same manner as in Example 1, except that 100y of methylbenzophenone imine (28.4% methylbenzophenone imine, the rest was methylbenzophenone imine) was used.

Imine after oxidation is 2.5%, and after imine decomposition is 0.27%.
It was hot.

Example 45 4-Tert butylbenzophenonimine (4-Ter
21.5% t-butylbenzophenonimine, the rest is 4-
Tert. The oxidized and unreacted imine was decomposed in exactly the same manner as in Example 1, except that 100y (butylbenzophenone) was used.

Imine after oxidation is 2.0%, and after imine decomposition is 0.25%.
It was hot.

Comparative Example 1 Benzophenonimine was oxidized under the same conditions as Example 1,
A reaction solution was obtained in which the azine yield was 86.5% and the unreacted imine was 3.05%.

Imine decomposition was attempted under the same conditions as in Example 1, in which any imine decomposition catalyst was added.

After 1 hour of reaction, the imine was 3.01%, which was hardly decomposed.

Comparative Example 2 Benzophenone imine was oxidized under the same conditions as in Example 34 to obtain a reaction solution with an azine yield of 80% and an unreacted imine of 3.20%.

Imine decomposition was attempted under the same conditions as in Example 34 without adding any imine decomposition catalyst.

After 1 hour of reaction, the imine was 2.98%, which was hardly decomposed.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the above formula, R^1 and R^2 have 1 to 1 carbon atoms.
10 chain type, cycloaliphatic or aromatic hydrocarbon groups, and ether groups consisting of the hydrocarbon groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, disubstituted amino groups, and halogen groups, hydroxy groups, nitro groups, The same or different groups selected from the group consisting of cyano groups, or R^1 and R^2 may be taken together to represent a single bond or ring. Further, it is m, n, or 0 or an integer from 1 to 5. ) is oxidized with molecular oxygen in the presence of a copper catalyst to produce benzophenoneazines, and then the unreacted benzophenone imines remaining in this oxidized solution are oxidized into groups III to V of the periodic table. water in the presence of an oxide of an element belonging to the group and belonging to the second to fifth period (excluding phosphorus, nitrogen and carbon) and an element selected from iron, tungsten, bismuth, cerium, thorium, neodymium. A method for recovering ammonia from benzophenone imines, the method comprising recovering ammonia by reacting with benzophenone imine.