JP3401768B2 - Production method of lactones - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing lactones by liquid phase oxidation of alicyclic ketones.

[0002]

BACKGROUND OF THE INVENTION Lactones are useful substances used in various industrial chemicals such as solvents, functional resins, and pharmaceuticals, and their synthetic intermediates. The following various methods are known as methods for producing lactones.

Japanese Patent Publication No. 39-5921 discloses a method for producing cyclic lactones such as ε-caprolactone and carboxylic acids by reacting cyclic ketones such as cyclohexanone in the presence of a catalyst, an oxygen-containing gas and aldehydes. Is disclosed. In the method, as a catalyst, cobalt, manganese, platinum, palladium, vanadium, ruthenium, zirconium, aluminum, antimony,
Although a metal compound of beryllium or copper is used, the yield of lactones is low, and in particular, a heavy metal compound catalyst has problems in toxicity and separation of the reaction product from the catalyst. JP-A-53-25516 is characterized in that a chromium compound as a catalyst is dissolved in the reaction system, but like the above, it is unsatisfactory in terms of yield and toxicity of lactones. Japanese Patent Publication No. 55-36667 is characterized by adding a peracid when liquid-phase oxidizing cyclic ketones in the presence of aldehydes and molecular oxygen. However,
There are safety and economic disadvantages due to the use of peracid.
Further, in JP-A-5-65245, if the production conditions using a catalyst-free system or a cobalt catalyst known from JP-B-39-5921 are adopted, and cyclic ketones and aldehydes are reacted under limited conditions. It is described that by-products can be suppressed. However, there is no teaching or suggestion of new catalyst species.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a novel production method in which lactones can be obtained in a high yield under mild reaction conditions, there is no toxicity due to the catalyst, and the catalyst can be easily separated from the reaction system. The purpose is to provide the law.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems of the prior art, the inventors of the present invention have conducted extensive studies on the catalyst used during the reaction. As a result, the inventors have obtained the knowledge that the problems of the prior art can be solved only by using a specific catalyst, and completed the present invention.

That is, the present invention is a method for producing lactones by liquid-phase oxidation of alicyclic ketones in the presence of a catalyst, aldehydes and oxygen, wherein the catalyst is a solid base catalyst. The present invention relates to a method for producing lactones.

As the alicyclic ketones which are the raw materials in the present invention, various known ones can be used without particular limitation.
Specific examples thereof include cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-
Methylcyclohexanone, 2-ethylcyclohexanone, 2-isopropyl-5-methylcyclohexanone,
2-methoxycyclohexanone, 4-methoxycyclohexanone, 3,3,5-trimethylcyclohexanone,
Examples include cycloheptanone.

The basic solid catalyst used in the present invention includes alkali metal oxides such as Na ₂ O, K ₂ O, Rb ₂ O and Cs ₂ O; alkaline earth metals such as MgO, CaO, SrO and BaO. Oxides: La ₂ O ₃ , ZrO ₂ , ThO ₂ ; Na-Al ₂ O ₃ , alkali metal-supported oxides such as K-SiO ₂ ; Na-Y, Na-mordenite, Na-Z
Examples thereof include alkali metal-exchanged zeolites such as SM3; hydrotalcites, various similar compounds, and the like.

[0009] The above hydrotalcite has the formula: [M 1-x 2+ M x 3+ (OH) 2 ] x + [A x / n n- · mH 2
O] x- (in the formula, M 2+ represents a divalent metal, M 3+ represents a trivalent metal, A n- represents an n-valent anion, and x represents 0 to 0.33). Two
Examples of the valent metal include Mg 2+ , Zn 2+ , Ni 2+ and the like, trivalent metals such as Al 3+ , Fe 3+ and Cr 3+ , and examples of the n-valent anion include Cl − and NO 3 −. , CO 3 2− , salicylic acid, oxalic acid, citric acid and the like can be exemplified. The hydrotalcite-like compound does not satisfy the range of x in the above formula, for example, [Mg 2 Al 2 (OH) 8 ] + [(CO 3 ).
mH 2 O] - it is true. Of these hydrotalcites and their similar compounds, the Mg-Al-CO 3 system and the Mg-Al-Cl system are the most typical and easily available.

The amount of the basic solid catalyst used is usually 0.5 to 25% by weight with respect to the alicyclic ketone as a raw material.
It is about 1 to 15% by weight, preferably. 0.5% by weight
If it is less than the above range, a sufficient reaction rate cannot be obtained because the catalytic effect is low. On the other hand, if it exceeds 25% by weight, it is disadvantageous in terms of catalyst cost and catalyst separation work.

Except for hydrotalcites, the above basic solid catalysts usually have a basic point of 4 or less because gases such as oxygen and nitrogen are easily adsorbed and desorbed.
It is preferable to treat at a high temperature of 00 ° C. or higher to develop a basic point before use. Hydrotalcites are most preferable because they exhibit sufficient catalytic activity regardless of such high temperature treatment.

In the production method of the present invention, it is not always necessary to carry out the reaction in the presence of a solvent, but from the viewpoint of the yield of the lactone compound, the following solvent system is preferably used.
As the solvent, at least one selected from alkyl nitrites, alkyl halides, carbon halides, inert ketones other than the above-mentioned starting ketones, esters and aromatic hydrocarbons can be used.

Among the above solvents, examples of alkyl nitriles include various known ones such as acetonitrile, propionnitrile, butyl nitrile, etc., among which acetonitrile is preferred. Known alkyl halides can be used, but those having about 1 to 5 carbon atoms are preferable, and dichloromethane, trichloromethane, dichloroethane, trichloroethane, dichloropropane, dichlorobutane, trichloropropane, trichlorobutane,
Examples include tetrachloropropane and tetrachlorobutane. Examples of the halogenated carbon include carbon tetrachloride, hexachloroethane, octachloropropane and the like. As the ketones, inert ketones that do not participate in the liquid phase oxidation of the present invention correspond, and examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, dibutyl ketone and the like. Examples of the esters include methyl acetate, ethyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, isobutyl propionate and the like, and aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, isobutylbenzene and tetralin. Etc. can be illustrated. Any of the above solvents may be used alone or in combination of two or more. Among the above solvents, alkyl halides are preferable, and dichloroethane is particularly preferable, from the viewpoint of the yield of lactones.

The amounts of the alicyclic ketones, aldehydes and optionally used solvent may be appropriately determined according to the kind of the ketone. Usually, 1 part by mole or more of aldehydes, preferably 1 to 50 parts by weight with respect to 1 part by mole of the ketones.
The molar part. When the amount of aldehydes is less than 1 part by mole, the reaction is difficult to proceed sufficiently. The amount of solvent used is aldehydes 1
1 part by weight or more, preferably 2 to 12 parts by weight
5 parts by weight. If the amount of solvent used is less than 1 part by weight, the reaction rate will decrease.

In the production method of the present invention, a predetermined amount of aldehydes is dissolved in the solvent, and the aldehydes are auto-oxidized in an oxygen atmosphere to generate peroxides. A two-step method of quantitatively adding and lactonizing this can be adopted, or a one-step method of lactonizing a predetermined amount of raw material ketones at the same time when peroxide as an intermediate is generated. The one-step method is preferable in terms of reaction efficiency.

In the production method of the present invention, there is no particular limitation on the method for forming an oxygen atmosphere, and for example, if an oxygen flow is supplied to the gas phase of the reaction system or oxygen is bubbled directly into the liquid phase, the oxygen atmosphere can be easily obtained. Can be prepared. Oxygen supply is
It must be carefully determined because it correlates with the amount of peracid generated in the reaction system. Normally, the supply amount of the reaction solution per unit volume per unit time is 0.1 to 1200 liters hr ^-1 liters.
⁻¹ , preferably 25 to 200 liters · hr ⁻¹ · liter ⁻¹ .

The production method of the present invention is characterized in that the lactone compound can be obtained in good yield at normal pressure by employing the above-mentioned specific catalyst, but the pressurization condition is not excluded. The reaction temperature is preferably a temperature at which the peracid generated from the aldehydes is not decomposed, and usually 5
To about 65 ° C, more preferably 30 to 50 ° C. 6
If it exceeds 5 ° C, the yield of lactone tends to decrease. When using a solvent and reacting at normal pressure,
It is preferable that the temperature is within the above temperature range and below the boiling point of the solvent. The reaction time varies depending on the kind of the starting ketones and the reaction temperature, but is usually about 2 to 10 hours.

[0018]

According to the present invention, lactones can be produced from alicyclic ketones in a high yield of about 50 to 100% under mild conditions. In addition, since the present invention uses a solid base catalyst, it has effects such as no toxicity and easy separation and disposal of the catalyst.

[0019]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples.

Example 1 In a 100 ml _three- necked flask equipped with a reflux tube, 15 ml of dichloroethane as a solvent and hydrotalcite as a catalyst ([Mg ₁₀ Al ₂ (OH) ₂₄ ] ⁺ [(CO ₃ ) .mH ₂ O)] ^- )
0.025 g and 1.22 ml of benzaldehyde as an aldehyde compound were added, the mixture was heated to 40 ° C., and then oxygen was bubbled for 30 minutes at a supply rate of 45 to 55 ml / min. Next, 0.352 g of cyclopentanone as a raw material alicyclic ketone was previously added to 5 ml of dichloroethane (4.
A solution in which 18 mmol) was dissolved was added dropwise over 10 minutes, and the mixture was further reacted for 4 hours and 20 minutes to obtain the target product, lactone. The lactone was analyzed by gas chromatography. Table 1 shows the conversion rate and the selectivity. The selectivity refers to the ratio of the target product in the converted raw materials.

Examples 2 to 14 and Comparative Examples 1 to 6 The same procedure as in Example 1 was carried out except that at least one of the starting material ketones, the catalyst and the solvent was replaced as shown in Table 1.
Table 1 shows the conversion rate and the selectivity.

[0022]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI // C07B 61/00 300 C07B 61/00 300 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C07D 309/30 B01J 27/138 B01J 27/236 C07D 313/04 C07D 313/16 C07B 61/00 300 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A method for producing a lactone by subjecting an alicyclic ketone to liquid phase oxidation in the presence of a catalyst, an aldehyde and oxygen, wherein the lactone is a solid base catalyst. Manufacturing method. 2. The method according to claim 1, wherein the solid base catalyst is hydrotalcites. 3. An organic solvent is present in the reaction system.
Or the production method described in 2. 4. The organic solvent is at least one selected from alkyl nitrites, alkyl halides, halogenated carbons, inert ketones other than the alicyclic ketones, esters and aromatic hydrocarbons. Item 3. The production method according to Item 3.