JPS63225329A - Production of alpha,beta-unsaturated ketone - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for organic synthesis and solvent by one-stage reaction, by condensing ketones through dehydration by the use of an oxide or hydroxide of a metal selected from the group consisting of Ce, Ti, Zr, Hf, Ta and Cr as a catalyst. CONSTITUTION:A ketone shown by formula I (R<1> is H or alkyl; R<2> is alkyl) is condensed with a ketone shown by formula II (R<3> is H or alkyl; R<4> is alkyl) through dehydration by the use of a highly active ketone condensation catalyst comprising at least one metallic oxide or hydroxide (e.g. ceric hydroxide, titanium tetrabutoxide, hafnium oxychloride and tantalum pentachloride) of metal selected from the group consisting of cerium, titanium, zirconium, hafnium, tantalum and chromium to give an alpha,beta-unsaturated ketone (e.g. mesityl oxide or 5-methyl-4-hepten-3-one). The ketone shown by formula I may be the same or different from the ketone shown by formula II.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing α,β-unsaturated ketones useful as raw materials for organic synthesis, solvents, and the like.

[Conventional technology]

Conventionally, various methods have been proposed for producing α,β-unsaturated ketones. For example, to describe a method for producing mesityl oxide (4t-methyl-3-pentene-kone), which is a typical α,β-unsaturated ketone, mesityl oxide is produced by condensing acetone in the presence of a catalyst. There are well-known methods to do this, the most typical of which are as follows.

■ Aldol addition of acetone in the presence of a basic catalyst (
A method of obtaining mesityl oxide by conducting a so-called aldol condensation) to obtain diacetone alcohol, and then dehydrating this in the presence of an acid catalyst.

■ A method to obtain mesityl oxide by dehydrating and condensing acetone in the presence of a catalyst such as zirconium phosphate or alumina.

[Problem that the invention seeks to solve]

However, in method (■) above, the reaction is in two stages;
In addition, it is difficult to carry out the aldol addition reaction of acetone at a high conversion rate, so it cannot be said to be efficient enough. In addition, the method (■) above is a /step reaction, but
Since the catalyst activity is relatively low, it is necessary to use a large amount of catalyst, which poses a practical problem.

[Means for solving problems]

In order to solve the problems of the prior art, the present inventors have worked hard to find a highly active ketone condensation catalyst. As a result, by using a specific metal oxide or hydroxide as a catalyst, The inventors have discovered that the above problems can be solved and have arrived at the present invention.

That is, the gist of the present invention is to convert a ketone represented by general formula (I): R1(H2C!0R2 (wherein R1 represents hydrogen or an alkyl group, and R2 represents an alkyl group) into general formula (II): R8CH2COR' (in the formula, R11 represents hydrogen or an alkyl group, and R4 represents an alkyl group) is dehydrated and condensed with a ketone represented by the general formula (■): RI C!H2C!: CC!0R4 (in the formula, R1,
R2, R3 and R4 are the same as above)
- In producing the unsaturated ketone, oxides or hydroxides of at least seven metals selected from the group consisting of cerium, titanium, zirconium, hafnium, tantalum, and chromium are used as catalysts. α, β−
A method for producing an unsaturated ketone.

The method of the present invention will be explained in detail below.

The ketones represented by the above general formula (1) and general formula (■) used as raw materials in the method of the present invention may be the same or different. As this stronger ketone, dialkyl ketones with an alkyl group having from / to 10 carbon atoms are preferably used, and specifically, acetone, methyl ethyl ketone (coftanone), cobentanone, 3-pentanone, cohexanone, 3-hexanone, 2- heptanone,
3-heptanone, co-octanone, 3-octanone, goo-octanone, conononanone, 3-nonanone, goononanone,! -nonanone, dinonyl ketone, etc.

In the present invention, it is important to use an oxide or hydroxide of cerium, titanium, zirconium, hafnium, tantalum or hachromium as a catalyst. Known methods can be used to prepare such metal oxides or hydroxides, such as adding an alkali to a solution of a soluble salt of the metal species to precipitate it, or hydrolyzing an alkoxide of the metal species. methods, thermal decomposition methods, oxidation methods, etc.

When the catalyst thus prepared is prepared in an aqueous solution, it is obtained as a hydroxide or oxide containing water, but it can be dehydrated by heating the catalyst in such a state.

Generally, the activity of the catalyst used for the condensation reaction of ketones is
The catalyst of the present invention varies depending on the type of metal used, heating temperature, dehydration temperature, etc., and some exhibit maximum activity in a hydrated state, and others exhibit maximum activity after dehydration. Compared to various catalysts, it has high reaction activity for ketone condensation reactions regardless of the presence or absence of water content. Therefore, the catalyst of the present invention is in the form of an oxide or a hydroxide, but the oxide may be a hydrous oxide.

The condensation reaction of the present invention can be carried out either in the gas phase or in the liquid phase. Higher yields are usually obtained in the liquid phase.

In the case of a liquid phase, the reaction temperature is preferably lower than the critical temperature of the ketone (235°C in the case of acetone). If the temperature is too low, the reaction rate will be low, so the reaction temperature is preferably 3θ.
The temperature is selected within the range of 200°C to 200°C. The catalyst may be used in a fixed bed or in a suspended bed. In the case of a suspended bed, the amount of catalyst used may be about 30 to 30 grams per ketone. In view of the selectivity of the target product, it is preferable to keep the conversion rate of ketone to 20% or less. The reaction pressure includes the pressure generated by the ketone itself, but this is not a decisive factor. It is desirable that no air be mixed into the atmosphere. The target compound can be separated from the reaction product by a conventional method.

The corresponding α,β-unsaturated ketone of the general formula (It) can be obtained by dehydration condensation of a diketone according to the method of the present invention. For example, mesityl oxide from acetone and methyl ethyl ketone! -Methyl-ghebutene-3-one, acetone and methyl ethyl ketone! -Cara J--Methyl-guhexen-3-one and/or C<'-methyl-3-hexene-kone, dinonylketone cara//
-octyl-/2-nonyl-//-heneicosene-1
0-on can be obtained respectively.

〔Example〕

Next, specific embodiments of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited by these Examples unless the gist thereof is exceeded.

Example/ Commercially available ceric hydroxide (manufactured by Wako Tsumugi Co., Ltd.), Q2 and acetone θ- were placed in a stainless steel autoclave with an internal volume of about 70 θ, and reacted at 750° C. for 7 hours.

After cooling, the reaction solution was analyzed by gas chromatography. The results are shown in Table-/.

Example 2 After calcining the ceric hydroxide used in Example 2 at 500° C., the same procedure as Example 2 was carried out except that 0.72 was used as a catalyst. The results are shown in Table-/.

Example 3 - Titanic acid obtained by hydrolysis of titanium tetrabutoxide was dried at 700°C, and then used in a reaction using θV as a catalyst under the same conditions as in Example. Further, this titanic acid was calcined at SOO° C. and then used in a reaction using 8θ2 as a catalyst under the same conditions. The reaction results are shown in Table-/.

Examples j to 7 Zirconium hydroxide (manufactured by Shin Nippon Metal Co., Ltd.) was used as a catalyst (as in the example or as a catalyst obtained by firing at 500°C (Example 6) and 700°C (Example 7)), 0t Except for the above, the same procedure as in Example 1 was carried out.The results are summarized in Table 1.

Example/~9 Dissolve 2Jrf of oxychloride in /l of water,
jN-ammonia water was added, and the resulting precipitate was thoroughly washed with water until no chlorine ions were detected, to obtain hafnium hydroxide. After drying this hydroxide at 700℃,
Alternatively, it was used in the reaction after being calcined at SOO°C. The amount of catalyst was O1 for each reaction, and the reaction conditions were the same as in Example. The results are summarized in Table-/.

Example/Q Tantalum pentachloride 2! After dissolving in 0 d of ethanol to form ethoxide, a solution of potassium hydroxide in ethanol (
29/l) was added dropwise to form a precipitate. This precipitation/
After boiling and washing with N-MCI, the product was thoroughly boiled and washed with demineralized water and dried at 700°C to obtain tantalic acid. The reaction was carried out at 750°C for 7 hours using 7.02% of this tantalic acid as a catalyst. The results are shown in Table-/.

Example//~/2 Chromium nitrate? Hydrate 4 toys! The precipitate was dissolved in 00 at of water, 4tN-ammonia water was added, and the resulting precipitate was thoroughly washed with water and dried at 700°C (temporarily 0r(OH)).
3). In this 0r(OH)3 and nitrogen stream! 0θ
The reaction was carried out under the same conditions as in Example 1 using 8θV of chromium oxide treated at ℃ as a catalyst. The results are shown in Table-/.

/) Mho: mesityl oxide (including double bond isomer), 2) DAA: diacetone alcohol Example/3 Catalyst Q obtained by calcining zirconium hydroxide (manufactured by Shin Nippon Metal Co., Ltd.) at 300°C ,! 2 and methyl ethyl ketone 20
m1 was charged into a stainless steel autoclave with an internal volume of 700 cm, and reacted at 750°C for 7 hours. After cooling, the reaction solution was analyzed by gas chromatography. As a result, the conversion rate of methyl ethyl ketone was /4t1%,
The selectivity for the product cv s-methyl-terhebuten-3-one was 6.2.

〔Effect of the invention〕

α useful as a raw material for organic synthesis, a solvent, etc. according to the method of the present invention
, β-unsaturated ketones can be produced economically.

Patent applicant: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - Others/names

Claims (1)

[Claims] (1) General formula (I): R^1CH_2COR^2 (wherein, R^1 represents hydrogen or an alkyl group, and R^2
represents an alkyl group. ) is represented by the general formula (II): R^3CH_2COR^4 (wherein, R^3 represents hydrogen or an alkyl group, and R^4
represents an alkyl group. ) is dehydrated and condensed with a ketone represented by the general formula (III): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1, R^2, R^3 and R^4 are the same as above. ), an oxide or hydroxide of at least one metal selected from the group consisting of cerium, titanium, zirconium, hafnium, tantalum, and chromium as a catalyst. A method for producing an α,β-unsaturated ketone, the method comprising: