JPH06293749A - Production of lactones - Google Patents

Abstract

PURPOSE:To provide a method capable of producing a lactone with a high selectivity from a cyclic ketone by using inexpensive acetaldehyde. CONSTITUTION:In a method for producing a lactone by reacting a cyclic ketone with acetaldehyde in the presence of an oxygen-containing gas, this production method is carried out by allowing the reaction to take place in the presence of a soluble divalent nickel salt catalyst.

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, more specifically, a cyclic ketone and acetaldehyde are reacted with an oxygen-containing gas in the presence of a divalent nickel salt catalyst to produce lactones. Regarding the method.

[0002]

2. Description of the Related Art It has been known that carboxylic acids corresponding to lactones and aldehydes can be obtained by reacting an aldehyde such as a cyclic ketone or acetaldehyde with an oxygen-containing gas (Japanese Patent Publication No. 41-41). 633
No. 0, Japanese Patent Publication No. 41-8930, Japanese Patent Publication No. 42-1084
No. 4, Japanese Patent Publication No. 43-16145). In these methods, a catalyst is usually required, and a compound such as cobalt, manganese, iron, copper, platinum or palladium is used. However, these methods generally have low selectivity for lactones. Further, a method using a soluble nickel salt as a catalyst and benzaldehyde as an aldehyde is known (see Japanese Patent Publication No. 46-12456). However, this method is an industrial method for producing lactones because the cost of benzaldehyde is high and a large amount of benzoic acid is by-produced by co-oxidation and the selectivity of lactones is not high enough. It cannot be said that the technology is satisfactory.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of solving the above-mentioned drawbacks of the lactone production method. Specifically, it is industrially easily available as an aldehyde. Using inexpensive acetaldehyde,
It is to provide a method capable of producing lactones with a high selectivity.

[0004]

According to the research conducted by the present inventors, the object of the present invention is to provide a method for producing a lactone by reacting a cyclic ketone with acetaldehyde in the presence of an oxygen-containing gas, It was found to be achieved by a method for producing lactones, which is characterized in that the reaction is carried out in the presence of a divalent nickel salt catalyst soluble in the reaction system.

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

In the method of the present invention, various cyclic ketones can be used as a starting material. Preferred cyclic ketones include 4- to 8-membered ring ketones, and these cyclic ketones may have a substituent as long as they do not interfere with the reaction. Examples of the substituent include a lower alkyl group having 5 or less carbon atoms, particularly a lower alkyl group having 1 to 2 carbon atoms, and these can be substituted by 1 to 3. Further, polycyclic ketones obtained by combining side chains can be widely used as a raw material. Preferably, 3 or less, more preferably monocyclic ketones are used. Specific compounds of the cyclic ketone are, for example, cyclobutanone, cyclopentanone, cyclohexanone, cyclopentanone, cyclooctanone or alkyl-substituted compounds thereof.
-Methylcyclobutanone, 3-methylcyclobutanone,
2-ethylcyclobutanone, 2-propylcyclobutanone, 2-butylcyclobutanone, 2,2-dimethylcyclobutanone, 2,3-dimethylcyclobutanone, 2-methylcyclopentanone, 3-methylcyclopentanone,
2-ethylcyclopentanone, 2-propylcyclopentanone, 2-butylcyclopentanone, 2,2-dimethylcyclopentanone, 2,3-dimethylcyclopentanone, 3,4-dimethylcyclopentanone, 2, 4-dimethylcyclopentanone, 2,5-dimethylcyclopentanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 2-ethylcyclohexanone, 2-propylcyclohexanone, 2-
Butylcyclohexanone, 2,2-dimethylcyclohexanone, 2,3-dimethylcyclohexanone, 2,4-dimethylcyclohexanone, 2,5-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 3,4-dimethylcyclohexanone, 3,5-dimethyl Cyclohexanone, 2-methylcycloheptanone, 3-methylcycloheptanone, 4-methylcyclopentanone, 2-ethylcycloheptanone, 2-propylcycloheptanone,
2-butylcycloheptanone, 2,2-dimethylcycloheptanone, 2,3-dimethylcycloheptanone, 2,4
-Dimethylcycloheptanone, 2,5-dimethylcycloheptanone, 2,6-dimethylcycloheptanone, 2,7
-Dimethylcycloheptanone, 3,4-dimethylcycloheptanone, 3,5-dimethylcycloheptanone, 3,6
-Dimethylcycloheptanone, 4,5-dimethylcycloheptanone, 2-methylcyclooctanone, 3-methylcyclooctanone, 4-methylcyclooctanone, 5-
Methylcyclooctanone, 2-ethylcyclooctanone, 2-propylcyclooctanone, 2-butylcyclooctanone, 2,2-dimethylcyclooctanone, 2,3
-Dimethylcyclooctanone, 2,4-dimethylcyclooctanone, 2,5-dimethylcyclooctanone, 2,6
-Dimethylcyclooctanone, 2,7-dimethylcyclooctanone, 2,8-dimethylcyclooctanone, 3,4
-Dimethylcyclooctanone, 3,5-dimethylcyclooctanone, 3,6-dimethylcyclooctanone, 3,7
-Dimethylcyclooctanone, 4,5-dimethylcyclooctanone, 4,6-dimethylcyclooctanone, cyclodecanone, cyclododecanone, selumbon and the like. Further, as the polycyclic ketones, α-cyperone, β
-Cyperon, Cholestan-4-one, Cholestan-1-
On, tetrahydro-α-cyperone and the like can be mentioned.

The amount of acetaldehyde used in the method of the present invention is preferably in the range of 0.3 times to 6 times, and more preferably 0.5 times to that of the starting cyclic ketone.
A 5-fold molar range is preferred. When the amount of acetaldehyde is larger than the above range relative to the cyclic ketone, the yield of lactones is high, but the amount of acetic acid produced from acetaldehyde is increased, which is not preferable. On the other hand, if the amount of acetaldehyde is less than the above range, the yield of lactones will be low, which is not desirable.

In the method of the present invention, the divalent nickel salt soluble in the reaction system used as the catalyst is an inorganic salt such as nickel chloride, nickel bromide, nickel carbonate, nickel perchlorate, nickel sulfate or nickel nitrate, Nickel formate, nickel pivalate, nickel valerate, nickel hexanoate, nickel 2-ethylhexanoate, nickel stearate, nickel cyclohexylbutyrate, nickel benzoate, nickel carboxylic acid salts such as nickel naphthenate or nickel benzenesulfonate, p. -Nickel sulfonate such as nickel toluenesulfonate is used, preferably divalent nickel salt of carboxylic acid is used, and nickel acetate is particularly preferable. The amount of these catalysts used is preferably 0.0001 to 1% by weight, more preferably 0.005 to 0.1% by weight, based on the total weight of the reaction mixture.

A reaction solvent may or may not be used in the method of the present invention. As the reaction solvent, a solvent inert to the reaction, for example, benzene, chlorobenzene, dichlorobenzene, ethyl acetate, acetonitrile, chloroform acetate, 1,2-dichloroethane, acetone and the like can be used, and particularly benzene, chlorobenzene, dichlorobenzene. Alternatively, aromatic or halogenated hydrocarbons such as 1,2-dichloroethane are preferred. These solvents can be used alone or in combination.

The reaction in the method of the present invention may be carried out continuously or batchwise in the liquid phase. The reaction temperature is preferably in the range of 25 ° C to 80 ° C, particularly preferably in the range of 40 ° C to 70 ° C. If the reaction temperature is lower than the above range, the reaction rate becomes slow, while if it is higher than the above range, the ratio of side reaction increases and the yield of the target product decreases. The reaction time depends on the cyclic ketone used and the reaction temperature, but is usually about 0.5 to 10 hours. The reaction pressure is not particularly limited and may be atmospheric pressure or increased pressure as long as it is sufficient to keep the reaction system in the liquid phase, but is usually atmospheric pressure to 50.
The range of kg / cm ² is preferred. As the oxygen-containing gas used in the reaction, pure oxygen, air or oxygen diluted with nitrogen, helium, argon or the like can be used.

The lactones obtained by the method of the present invention are useful as raw materials for lactams, polymers and the like.

[0012]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples. The lactone selectivity in Examples and Comparative Examples is
It refers to the mole percentage of lactone formed relative to the converted cyclic ketone.

Example 1 Cyclohexanone 1.97 was placed in a 50 ml autoclave.
g, benzene 17.1 g, acetaldehyde 0.88 g and anhydrous nickel acetate 4 mg, and oxygen gas 5 kg
Pressurize to / cm ² . The autoclave was immersed in a hot water bath at 50 ° C. and reacted for 4 hours while stirring. After completion of the reaction, the reaction solution was analyzed by gas chromatography to find that ε-
The yield of caprolactone was 1.19 g. The selectivity for ε-caprolactone was 99%.

Example 2 At a reaction temperature of 50 ° C., 4.3 g of cyclohexanone, 40 g of benzene, 5.8 g of acetaldehyde, and 0.009 g of anhydrous nickel acetate 0.009 g were continuously added to a completely mixed continuous reactor having a reaction volume of 200 ml. Meanwhile, oxygen gas was blown at a flow rate of 100 ml / min to cause a reaction. When the effluent was analyzed by gas chromatography, the yield of ε-caprolactone was 2.27 g / hr. The selectivity for ε-caprolactone was 98%.

Example 3 In a 100 ml reaction vessel equipped with a mechanical stirrer, an oxygen introduction tube, and an acetone-dry ice cooler, 5.0 g of cyclohexanone, 43 g of benzene, and 2.26 of acetaldehyde.
g and 0.01 g of anhydrous nickel benzoate were added, and while blowing oxygen gas at a flow rate of 50 ml / min, 50
The mixture was stirred at 0 ° C for 4 hours. After the reaction was completed, the reaction solution was analyzed by gas chromatography to find that the yield of ε-caprolactone was 1.87 g. The selectivity for ε-caprolactone was 95%.

Example 4 Example 4 was repeated except that anhydrous nickel chloride was used instead of anhydrous nickel benzoate. The yield of ε-caprolactone was 1.51 g. The selectivity for ε-caprolactone was 92%.

Example 5 Example 5 was repeated except that nickel carbonate was used instead of anhydrous nickel benzoate. The yield of ε-caprolactone was 1.16 g. The selectivity for ε-caprolactone was 93%.

Examples 6 to 8 Except that the solvents shown in Table 1 were used instead of benzene.
The same procedure as in Example 1 was performed. The results are summarized in Table 1.

[0019]

[Table 1]

Comparative Example 1 Cyclohexanone (5.0 g), benzene (43 g) and benzaldehyde (2.26) were placed in a 100 ml reaction vessel equipped with a mechanical stirrer, oxygen introduction tube and acetone-dry ice condenser.
g and 0.01 g of anhydrous nickel acetate were added, and the mixture was stirred at 50 ° C. for 4 hours while blowing oxygen gas at a flow rate of 50 ml / min. After completion of the reaction, the reaction solution was analyzed by gas chromatography to find that the yield of ε-caprolactone was 3.07 g. The selectivity for ε-caprolactone was 89%.

Comparative Example 2 0.2 m of cobalt acetate was used instead of anhydrous nickel benzoate.
The same procedure as in Example 3 was carried out except that g was used. The yield of ε-caprolactone was 1.55 g. The selectivity for ε-caprolactone was 86%.

Comparative Example 3 The procedure of Example 3 was repeated, except that tris (acetylacetonato) iron (III) was used instead of anhydrous nickel benzoate. The yield of ε-caprolactone was 1.31 g. The selectivity for ε-caprolactone was 87%.

[0023]

EFFECTS OF THE INVENTION According to the method of the present invention, lactones can be prepared with high selectivity by reacting inexpensive acetaldehyde and cyclic ketone with an oxygen-containing gas in the presence of a divalent nickel salt catalyst soluble in the reaction system. Obtainable.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C07D 313/00 9360-4C 313/16 9360-4C // C07B 61/00 300 (72) Inventor Shigeru Isayama 6-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Mitsui Petrochemical Industry Co., Ltd. (72) Inventor Masahiro Kuwahara 6-1-2, Waki, Waki-cho, Kuma-gun, Yamaguchi Within

Claims (4)

[Claims] 1. A method for producing a lactone by reacting a cyclic ketone with acetaldehyde in the presence of an oxygen-containing gas, wherein the reaction is carried out in the presence of a divalent nickel salt catalyst soluble in the reaction system. And a method for producing a lactone. 2. The method according to claim 1, wherein the catalyst is a divalent nickel salt of a carboxylic acid. 3. The catalyst is nickel acetate.
The method described. 4. The process according to claim 1, wherein the reaction is carried out in a reaction-inert aromatic hydrocarbon or halogenated hydrocarbon solvent.