JP2789774B2 - Method for producing ketones - Google Patents

Description

The present invention relates to a method for producing ketones useful as an organic synthetic intermediate.

[Prior Art] Conventionally, in a method for producing a corresponding ketone from a carboxylic acid compound or a derivative thereof by a gas phase contact reaction, a method using calcium oxide, alumina, or the like as a catalyst has been proposed (USP-4172097, Kuniaki 57-3516
9).

However, these catalysts have problems in acid resistance, service life, and the like.

On the other hand, a method using a zirconium oxide catalyst has also been proposed (JP-B-46-3044). Zirconium oxide catalysts are good in terms of acid resistance and initial reaction results, but have a short catalyst life and have drawbacks in regeneration. That is, in the ketone synthesis reaction, the carbonaceous substance accumulates on the catalyst surface as the reaction time elapses,
This leads to a decrease in catalyst performance. Regeneration of the catalyst with reduced catalytic activity is usually performed at a high temperature under the flow of gas containing oxygen gas,
It is carried out by burning off carbonaceous materials. However, zirconium oxide has a drawback that the combustion activity of carbonaceous materials is low, severe conditions are required for regeneration, and the process becomes complicated.

[Problems to be Solved by the Invention] The present invention focuses on the drawbacks of zirconium oxide catalysts, and solves the conventional problems by including specific components therein. It is an object of the present invention to provide a method for producing ketones at a high yield by a decarboxylation reaction of the derivative.

[Means for Solving the Problems] The present invention relates to a method for producing one molecule of ketone by a decarboxylation condensation reaction from two molecules of a carboxylic acid compound or a derivative thereof by a gas phase contact reaction, wherein the carboxylic acid compound or a derivative thereof is provided. Wherein at least one molecule has at least one hydrogen atom at the carbon at the α-position, and an oxide containing chromium and zirconium is used as a catalyst. Make a summary.

 Hereinafter, the present invention will be described in detail.

The synthesis reaction of ketones by the condensation reaction of the present invention can be shown as follows by expressing a carboxylic acid compound.

In the formula (1), it is necessary that at least one of the groups represented by R ₁ and R ₂ has at least one hydrogen atom at the carbon at the α-position to which the carboxylic acid is bonded. R ₁ and R ₂
Are the same, a symmetric ketone, and when R ₁ and R ₂ are different,
Gives an asymmetric ketone. When a compound sharing R ₁ and R ₂ has a carboxylic acid group at each of its terminals, the resulting ketone is a cyclic ketone. As such a carboxylic acid compound, a chain aliphatic carboxylic acid having a carboxylic acid group at both terminals can be cited. In this case, the chain portion needs to have two or more carbon atoms.

In the formation of symmetric ketones by self-condensation of the same kind of carboxylic acid compound, if there is no hydrogen atom bonded to the α-carbon to the carboxyl group, self-condensation is unlikely to occur, so at least one α-hydrogen is included It is necessary.

When asymmetric ketones are produced by cross-condensation of different kinds of carboxylic acid compounds, any one of the carboxylic acid compounds may be a compound containing at least one hydrogen atom on the α-carbon.

The carboxylic acid compound used in the present invention is an aromatic, aliphatic, or alicyclic carboxylic acid compound or a derivative thereof, and examples of the derivative include an ester or an acid anhydride.

The aromatic carboxylic acid compound may be a monocarboxylic acid compound or a polycarboxylic acid compound, and may have a substituent inert to the reaction. Specific examples of such compounds include benzoic acid, toluic acid, cumic acid,
Dimethylbenzoic acid, biphenylcarboxylic acid, anisic acid,
Phenoxybenzoic acid, chlorobenzoic acid, phthalic acid, hydroxybenzoic acid, acetylbenzoic acid, naphthoic acid, anthracenecarboxylic acid, and the like.

Preferably, benzoic acid, toluic acid, cumic acid, dimethylbenzoic acid, biphenylcarboxylic acid, anisic acid, phenoxybenzoic acid, acetylbenzoic acid, and naphthoic acid are exemplified.

Examples of the aliphatic carboxylic acid compound include a monocarboxylic acid compound having 1 to 20 carbon atoms or a polycarboxylic acid compound. Specifically, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid,
Saturated or unsaturated monocarboxylic acids such as decanoic acid, tetradecanoic acid, stearic acid, isostearic acid, acrylic acid, methacrylic acid, 10-undecenoic acid, 9-octadecenoic acid, oxalic acid, malonic acid, succinic acid, and glutaric acid And polycarboxylic acids such as adipic acid, decanic acid and octadecanoic acid.

Preferably, acetic acid, propionic acid, butyric acid, isobutyric acid,
Valeric acid, isovaleric acid, pivalic acid, hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, decanoic acid,
Examples include tetradecanoic acid, stearic acid, iristearic acid, acrylic acid, methacrylic acid, 10-undecenoic acid, 9-octadecenoic acid, succinic acid, glutaric acid, adipic acid, decanoic acid, and octadecanoic acid.

The alicyclic carboxylic acid compound is an alicyclic monocarboxylic acid compound or a polycarboxylic acid compound, for example,
Examples thereof include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

Preferably, cyclopentanecarboxylic acid and cyclohexanecarboxylic acid are used.

Incidentally, the aliphatic carboxylic acid or the alicyclic carboxylic acid may have an inert group such as an aryl group, a hydroxy group, or an ether group as a substituent, and when these compounds are specifically exemplified, Examples include phenylacetic acid, cinnamic acid, and glycolic acid.

Of these, a carboxylic acid compound having no α-hydrogen is used for producing an asymmetric ketone by a combination with a carboxylic acid compound containing one or more α-hydrogens.

The catalyst used in the method of the present invention is a catalyst comprising an oxide containing chromium and zirconium, and can be prepared by an ordinary method.

The zirconium oxide used in the catalyst of the present invention preferably has high chemical purity and is porous. For example, zirconyl hydroxide, zirconyl nitrate, zirconyl carbonate, or the like may be fired at about 300 to 950 ° C.

The chromium compounds used in the production of the catalyst include sulfates,
Inorganic salts such as nitrates, halides or chromic anhydrides, dichromates or ammonium salts thereof, alkali salts and the like, and organic salts such as formates, acetates, oxalates, etc. From the viewpoint of not containing impurities present, salts which decompose at a relatively low temperature and do not contain other poisoning elements, such as nitrate, chromic anhydride, ammonium bichromate, formate, acetate, and oxalate, are preferred. Various methods such as a method of impregnating a soluble chromium salt, a method of spraying, a coprecipitation method, and a kneading method can be applied as a method of incorporating chromium into zirconium oxide.

The amount of chromium added is 0.001 to 0.20, preferably 0.005 to 0.10, when expressed in atomic ratio to zirconium.
The degree is appropriate.

In order to actually use the obtained oxide containing chromium and zirconium as a catalyst, it is preferable to use an appropriate method such as extrusion molding or tablet molding, or to use the oxide supported on an inert carrier.

In the ketone synthesis reaction, as the reaction time elapses, carbonaceous material precipitates on the catalyst, and deterioration over time is observed.
The chromium-containing zirconia catalyst of the present invention is advantageous in that carbon deposition is suppressed and the catalyst life is longer than that of a chromium-free zirconia catalyst. Thus, when carried out industrially, it is necessary to regenerate the deteriorated catalyst.

In the case of a zirconia catalyst containing no chromium, the deteriorated catalyst can be reused if the deteriorated catalyst is regenerated by burning and removing the carbonaceous material precipitated at a high temperature in the presence of a gas containing oxygen. Since the oxidizing ability of zirconia itself is low, severe conditions such as a high oxygen concentration and a high temperature are required for regeneration.

However, the chromium-containing zirconia catalyst of the present invention is
Since the chromium has a high oxidation ability, it is possible to burn off the carbonaceous substances adhered under mild conditions as compared with a zirconia single catalyst, and the catalytic activity after regeneration is restored to the same level as the new catalyst.

Regeneration of the chromium-containing zirconia catalyst degraded by the reaction is performed at a temperature of 250 ° C. or more in the presence of an inert gas containing oxygen gas. And such an operation can be carried out industrially sufficiently. There is no problem using steam and CO ₂ as the inert gas.

The ketonization reaction of the method of the present invention is conveniently performed in the gas phase, and the reaction temperature is usually 250 to 500 ° C, preferably 300 to 450 ° C.
It is about ° C.

The reaction is usually carried out at normal pressure, but may be carried out under a slightly elevated or reduced pressure.

It is permissible to allow an accompanying gas such as water, nitrogen or carbon dioxide gas to coexist in the reaction system.

When the catalyst is used in a fixed bed, the space velocity of the starting carboxylic acid or its derivative is 0.01 to 10 as LHSV.
about hr ^-1, more preferably about to no 0.05 5 hr ^-1.

As the gas space velocity, GHSV, 100 to 20,
000 hr ⁻¹ , more preferably about 200 to 5000 hr ⁻¹ .

[Examples] The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples unless it exceeds the gist thereof.

Example 1 Commercially available zirconium oxyhydroxide (ZrO ₂ content = 85.4
(wt%) 200 g of an aqueous solution of 27.8 g of chromium nitrate / 9 hydrate dissolved in 500 ml of water was added, and evaporated to dryness.
After firing for an hour, an oxide powder was obtained. This powder is tablet-molded, then crushed and sieved to obtain an oxide catalyst of chromium and zirconium of 10 to 20 mesh (chromium addition amount: Cr / Zr atomic ratio =
5/100) was prepared. 20 ml of the catalyst thus prepared
Was used to carry out a synthesis reaction of propiophenone from benzoic acid and propionic acid.

Nitrogen is flowed at 10 / hr as diluent gas, and benzoic acid LHSV =
The reaction was carried out under the conditions of 0.10 kg / · catalyst hr, propionic acid LHSV = 0.30 kg / · catalyst hr, and a reaction temperature of 380 ° C. The GHSV of the reaction gas is 610 hr- ¹ .

Four hours after the start of the reaction, the conversion of benzoic acid was 79
% And propiophenone selectivity was 97%. Also, 10
The reaction results at 0 hours were as follows: benzoic acid conversion was 73%, propiophenone selectivity was 97%, and carbon deposition amount was 0.8% by weight based on the catalyst.

The catalyst with reduced activity after the reaction was treated with a 3% oxygen-containing gas (diluted with N ₂ ) at 350 ° C. for 10 hours to perform a catalyst regeneration treatment. (GHSV = 350 hr ^-1 ) The amount of carbon deposited on the catalyst after regeneration was reduced to 0.02% by weight. Using 10 ml of the regenerated catalyst, a synthesis reaction of propiophenone was subsequently performed. As a result, the conversion of benzoic acid was 78% and the selectivity for propiophenone was 97%. The activity was restored to the level of a new catalyst.

Examples 2 to 5 Using the catalyst shown in Example 1, various ketone synthesis reactions were performed. The results are shown in Table 1.

Comparative Example 1 Commercially available zirconium oxyhydroxide (ZrO ₂ content = 85.4
wt%) in air at 700 ° C for 3 hours.
_Two powders were prepared. Using the obtained powder, after tableting,
Pulverization and sieving operations were performed, and the particles were sized to 10 to 20 mesh to obtain a zirconia catalyst.

Using 20 ml of the obtained catalyst, a synthesis reaction of propiophenone was carried out under the same conditions as in Example 1 except that the reaction temperature was 360 ° C.

Four hours after the start of the reaction, the benzoic acid conversion rate was 70
% And propiophenone selectivity was 97%. The activity of the zirconia catalyst gradually decreases as the reaction time elapses,
The reaction results at the 100th hour were 55% benzoic acid conversion and 96% propiophenone selectivity.

After the reaction, the amount of carbon attached to the catalyst is 1.
8 percent by weight.

The deactivated catalyst after the reaction was subjected to a regenerating treatment in the same manner as in Example 1, but the amount of carbon adhering to the regenerated catalyst was 1.5% by weight and was not completely removed.

After this regeneration, a ketone synthesis reaction was subsequently carried out using 10 ml of the catalyst, but the conversion of benzoic acid was 59%, the selectivity of propiophenone was 96%, and the catalyst activity was not recovered.

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ identification symbol FI // C07B 61/00 300 C07B 61/00 300 (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 49/04 -49/185 C07C 49/76-49/86 C07C 45/48 C07B 61/00 CA (STN)

Claims (1)

(57) [Claims] 1. A method for producing one molecule of a ketone from a carboxylic acid compound or a derivative thereof by decarboxylation condensation reaction from two molecules by a gas phase contact reaction, wherein at least one molecule of the carboxylic acid compound or a derivative thereof has an α-position. A method for producing ketones, characterized by using one having at least one hydrogen atom in carbon and using an oxide containing chromium and zirconium as a catalyst.