JP2000080067A - Production of oxime - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing an oxime in the presence of a titanosilicate catalyst. SOLUTION: This method for producing an oxime comprises reacting a ketone or aldehyde with hydrogen peroxide and ammonia in the presence of a titanosilicate catalyst. Therein, the improvement comprises (1) charging water, the ammonia and a reaction solvent into a reactor and subsequently feeding the hydrogen peroxide and the ketone or aldehyde for their reaction by a batch reaction method, and (2) maintaining the content of water contained in the reaction system to 30-50 wt.% based on the total amount of the reaction solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for economically and efficiently producing various oxime compounds useful as analytical reagents and the like.

[0002]

2. Description of the Related Art Ammoximation of producing an oxime by liquid phase oxidation using hydrogen peroxide and ammonia in the presence of a ketone or aldehyde having a carbonyl group in the presence of a catalyst is widely known (German Patent 1,245,371). Etc.), in particular, the synthesis of cyclohexinosan oxime, which is an intermediate raw material for 6-nylon, using titanosilicate as a catalyst has been widely studied (Japanese Patent Publication No. 8-16091). This method is an excellent process in which ammonium sulfate produced as a by-product in the conventional oxime production process is not generated, and has many advantages such as easy separation operation because it is a solid catalyst.

[0003] However, in this method, ketone,
If the aldehyde is present in excess, the reaction solution is colored by a side reaction, and the oxime yield is reduced.If the hydrogen peroxide is present in an excessive amount, the generated oxime is further oxidized by hydrogen peroxide, Again, there was a problem that the oxime yield was reduced.

[0004]

SUMMARY OF THE INVENTION The present inventors have solved the above-mentioned problems and have an object to provide a method for obtaining an oxime in a high yield.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, after mixing a titanosilicate catalyst, a solvent, and ammonia, a ketone or aldehyde and a reaction solvent were mixed. By continuously supplying diluted hydrogen peroxide as a mixed solution and reacting ketone, aldehyde and hydrogen peroxide at a constant ratio in a reaction system in which a certain range of moisture is present,
The present inventors have found that a non-colored oxime compound having a yellowness of 5 or less as a result of a colorimeter can be obtained in a high yield by suppressing a side reaction, thereby completing the present invention.

That is, the present invention relates to a method for producing an oxime from a ketone or an aldehyde using hydrogen peroxide and ammonia in the presence of a titanosilicate catalyst, and (1) water, ammonia and a reaction solvent in a reactor. Then, hydrogen peroxide and a ketone or an aldehyde were supplied, and the reaction was carried out by a batch method. (2) The water content in the reaction system was reduced to 30 to 50 with respect to the total amount of the reaction solution. weight%
The present invention relates to a method for producing an oxime, characterized in that the oxime is maintained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing an oxime according to the present invention will be specifically described below. The catalyst used in the present invention is titanosilicate. What is titanosilicate?
It is obtained by substituting a part of silicon of crystalline silicalite having a zeolite structure with titanium. The method for synthesizing the titanosilicate used in the present invention is not particularly limited. For example, JP-A-56-97720 discloses the method.
Publication. Si / in titanosilicate
Those having a Ti ratio of 10 to 1000 are used. In the present invention, the amount of the titanosilicate catalyst used is not particularly limited. In the case of a suspension bed system, it is usually used in a range of 0.1% by weight to 10% by weight in the reaction solution. The catalyst may be in any form such as fine powder or pellets.

[0008] The hydrogen peroxide used in the present invention is usually
Hydrogen peroxide produced by the anthraquinone method or hydrogen peroxide synthesized by a direct oxidation method in which hydrogen and oxygen are brought into contact with a catalyst under high pressure, generally from 10% by weight to 7% by weight.
A commercially available 0% by weight aqueous solution can be used. Hydrogen peroxide is generally used as a stabilizer of phosphate, polyphosphate (sodium pyrophosphate, sodium tripolyphosphate, etc.), stannate, pyrophosphate, ascorbic acid, ethylenediaminetetraacetic acid,
Nitrotriacetic acid, aminotriacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetra (methylenephosphonic acid) and diethylenetriaminopenta (methylenephosphonic acid) can be used.

As the ammonia used in the present invention, it is possible to supply a gas before the start of the reaction or to use an aqueous ammonia solution. A method in which a part of ammonia is added directly or by dissolving an ammonium salt exemplified by ammonium sulfate, ammonium phosphate, ammonium chloride or the like soluble in water or hydrogen peroxide, a reaction solvent, or the like. Can also be used. The molar ratio of ammonia to ketones is preferably at least 1 with respect to the number of carbonyl groups, and more preferably at least 1.5.

The ketone and aldehyde used in the present invention are represented by the general formulas R ₁ and R ₂ C 2O, and include compounds having one or more carbonyl groups. Here, R ₁ and R ₂ include hydrogen, an alkyl group containing 1 to 12 carbon atoms, a branched alkyl group or a cycloalkyl group containing 3 to 12 carbon atoms, and 6 to 12 carbon atoms. represents a linear or branched alkylene group containing an aromatic group or a 3 to 12 carbon atoms, these alkyl groups, halogen, NO ₂ group, hydroxy group, may be substituted by an alkoxy group or a carboxylic acid ester. R ₁ , R
₂ may be the same or different from each other. Specifically, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones of cyclohexanone, or aldehydes such as benzaldehyde are preferably used.

In the oxime synthesis reaction method carried out in the present invention, for example, a raw material, a solvent, a catalyst and an additive are charged in advance into a reactor, and water or a reaction solvent, ketone or A batch method (batch method) in which the reaction is carried out by continuously supplying hydrogen peroxide whose concentration is adjusted by any one of the aldehydes, and after a certain period of time for completing the reaction, and then separating the generated oxime is preferable. The material of the reactor is preferably an inert material that prevents decomposition of hydrogen peroxide. For example, a glass lining or a stainless steel reaction vessel is preferable.

The reaction temperature for synthesizing oximes in the present invention is 5 ° C to 150 ° C, preferably 30 ° C to 120 ° C.
It is generally carried out in the range of ° C. There is no particular restriction on the pressure of the reaction, the initial pressure 3 kg / cm ² or more (absolute pressure) in order to keep the ammonia concentration in the system is preferably implemented in a range especially of 3~20kg / cm ^2. The present invention can be carried out even in a reaction under a higher pressure, but it is not preferable because a high pressure vessel is required and the method of adding the raw materials becomes a problem, which causes an increase in cost.

In the present invention, the preferred range of the molar ratio of hydrogen peroxide to ketone or aldehyde is from 0.5 to 3 with respect to the number of carbonyl groups, more preferably 0.5 to 3.
1.5. In addition, hydrogen peroxide can be used arbitrarily in the range of 5 to 60% by weight, and the concentration can be adjusted using water or a solvent used in the present reaction. Further, in order to suppress side reactions, the water concentration in the reaction system is
It is necessary to carry out the reaction in the range of 30 to 50% by weight with respect to the whole reaction solution. When the amount of water is high, the coloring is suppressed but the yield decreases, and when the amount of water is low, the oxime yield is almost maintained. However, the resulting oxime compound is colored and poses a problem.

As a solvent that can be used in the present invention, an alcohol is preferably used. Specifically, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, 2-butanol,
Examples thereof include t-butanol and t-amyl alcohol. Among them, t-butanol is most preferred. Two or more of these alcohols may be mixed and used.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

Example 1 A stainless steel (SUS316) autoclave equipped with a stirrer was charged with 11.3 g of pure water, 15.0 g of t-butanol, 3.8 g of ammonia and 3.0 g of titanosilicate, and the temperature was adjusted while stirring. The temperature was raised to 80 ° C. Thereafter, 38.9 g of a mixed solution of hydrogen peroxide (0.12 mol) and cyclohexanone (0.12 mol) was added over 3 hours. As the hydrogen peroxide, a commercially available product of 60% by weight was used, and the weight ratio of pure water to t-butanol was 2: 1 and diluted to 15% by weight. After the completion of the dropwise addition of the mixed solution of hydrogen peroxide and cyclohexanone, the reaction was further performed for 1 hour while maintaining the temperature and pressure to synthesize cyclohexanone oxime. After completion of the reaction, the inside of the reaction vessel was replaced with nitrogen to collect ammonia gas, and the pressure was reduced to atmospheric pressure to perform cooling.

The resulting reaction solution was separated by filtration through five types of C filter paper to separate the catalyst, and then subjected to gas chromatography (Grade by Shimadzu Corporation).
The yield of cyclohexanone oxime was measured by C-14A). As a result, the yield of cyclohexanone oxime based on hydrogen peroxide was 95.5%, and the conversion of hydrogen peroxide was determined to be 99.9% by iodometric titration. Also,
The color of the reaction solution was measured using a color difference meter (ND-300A manufactured by Nippon Denshoku) (transmission method, cell length: 10 mm), and its YI value (yellowness: ΔYI = 100 * (1.28X−
1.06Z) / Y｝, and X, Y, and Z are coefficients of the perfect diffuse reflection surface. Based on the above operation, the water content in the reaction system at the initial stage of charging was 37.5%, and was approximately 38% after the completion of the reaction.

Comparative Example 1 An autoclave was charged with cyclohexanone in advance, and
Example 1 except that weight% hydrogen peroxide was post-added in 3 hours.
The same operation as described above was performed. As a result, the yield of cyclohexanone oxime based on hydrogen peroxide was 92.8%, and the conversion of hydrogen peroxide was 99.9%. Also by color difference meter
The YI was determined to be 20.0. The water content in the reaction system at the initial stage of charging was 37.5%, and after completion of the reaction, the content was about 38%, which is the same as that in Example 1 except that the ketone was used first. The reaction was carried out by charging the mixture, and coloring was observed.

Comparative Example 2 A reaction was carried out under the same conditions as in Example 1 except that hydrogen peroxide was diluted to 15% by weight with pure water. As a result, the cyclohexanone oxime yield was reduced to 87.5%. The water content in this reaction system was 37.5% at the beginning and about 58% at the end of the reaction.
In addition, YI was determined to be 2.9 by a color difference meter.

Comparative Example 3 A reaction was carried out under the same conditions as in Example 1 except that hydrogen peroxide was diluted to 15% by weight with t-butanol. As a result, the yield of cyclohexanone oxime was 91.5.
%. The water content in this reaction system is 37.5% at the beginning and about 27% at the end of the reaction.
Met.

[0021]

According to the present invention, the coloring of the reaction solution and the decrease in the yield due to the side reaction can be suppressed, and the oxime of high purity can be produced in a high yield.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoko Matsuya 2-4-1-16 Hinagahigashi, Yokkaichi-shi, Mie F-term in the Yokkaichi Plant of Sanishi Gas Chemical Co., Ltd. F-term (reference) 4H006 AA02 AC59 BA10 BA33 BC31 BE14 BE32 BE60 BW18 DA35 4H039 CA73 CL50

Claims (1)

[Claims] 1. A method for producing an oxime from a ketone or an aldehyde using hydrogen peroxide and ammonia in the presence of a titanosilicate catalyst, comprising: (1) charging water, ammonia and a reaction solvent into a reactor, Hydrogen peroxide and a ketone or aldehyde are supplied to cause a reaction in a batch process, and (2) the water content in the reaction system is reduced to 30 to 50% by weight based on the total reaction solution. A method for producing an oxime, characterized in that the oxime is maintained.