JPH0322858B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing aliphatic carboxylic acids by oxidative cleavage of cyclic and/or acyclic aliphatic olefins. More specifically, cyclic and/or acyclic aliphatic olefins are oxidized by the action of a peroxide, and the resulting oxidation product is oxidatively cleaved with molecular oxygen in the presence of a specific catalyst to obtain high yields. The present invention relates to a method for producing aliphatic carboxylic acids at high yields.

Conventionally, a method using an oxidizing agent such as ozone, nitric acid, permanganate, etc. has been known as a method of cleaving cyclic and/or acyclic aliphatic olefins into aliphatic carboxylic acids. However, ozone and permanganate are expensive, and when cheap nitric acid is used, a large amount of polymer is produced and the yield is poor. Attempts have also been made to use hydrogen peroxide as an inexpensive oxidizing agent to replace these expensive oxidizing agents, to introduce a diol group adjacent to the double bond, and to air oxidize this in the presence of a cobalt salt catalyst. (Unexamined Japanese Patent Publication No. 47-6014
Publication No. 1970-1970, Japanese Patent Publication No. 47-9018
Publication No. 135909, Japanese Patent Application Laid-open No. 1973-
3815, JP-A-49-135908, etc.). However, this method has many problems in addition to the inability to selectively synthesize adjacent diols as intermediate raw materials, as well as the oxidative cleavage reaction itself. Generally, methods for introducing adjacent diol groups into unsaturated bonds include a method in which hydrogen peroxide and water are reacted in the presence of an acid catalyst to form adjacent diols in one step, and a method in which an epoxide is first formed and then hydrolyzed. Are known.
However, in the former, the reaction intermediate epoxide is unstable and has poor reaction selectivity because it coexists with acid.
It reacts again with the adjacent diol product to produce ether as a by-product. On the other hand, the latter requires many steps or requires special treatment such as heating the epoxide with water and a large amount of fatty acid salt at high temperature (Japanese Patent Laid-Open No. 57-57459). Additionally, this reaction of cleaving adjacent diol groups requires a long induction period, consumes expensive peracetic acid, ketones, aldehydes, etc., and requires extreme purification of raw materials and solvents in order to carry out continuous reactions. what must be done,
There are a number of disadvantages, including the need for measures such as the need to limit the supply so that the oxidation reaction does not stop. As mentioned above, none of the known methods is satisfactory as a method for producing aliphatic carboxylic acids by oxidative cleavage of cyclic and/or acyclic aliphatic olefins.

Dicarboxylic acids obtained from cycloaliphatic olefins are important as plasticizers and raw materials for polyesters, and monocarboxylic acids obtained from acyclic aliphatic olefins are important as raw materials for lubricants, etc.
On the other hand, since aliphatic olefins, which are raw materials, are easily and inexpensively available as petrochemical products, cyclic and/or acyclic aliphatic olefins are oxidatively cleaved to produce aliphatic carboxylic There is a need for a more advantageous method for manufacturing.

The present inventors have conducted intensive studies to find an excellent method for producing aliphatic carboxylic acids by oxidatively cleaving cyclic and/or acyclic aliphatic olefins using an inexpensive oxidizing agent or air. As a result, by oxidizing the oxidation product obtained by reacting a peroxide with a cyclic and/or acyclic aliphatic olefin with molecular oxygen in the presence of a specific catalyst, the desired product can be obtained in high yield. The present inventors have discovered that an aliphatic carboxylic acid can be obtained, and have completed the present invention.

That is, the present invention provides an oxidation product obtained by reacting a peroxide with a cyclic and/or acyclic aliphatic olefin having at least one unsaturated bond in its carbon chain. It is characterized by oxidative cleavage with molecular oxygen in the presence of a catalyst consisting of one or more heavy metals selected from manganese and cerium and a bromine compound, or the heavy metal, a bromine compound, and a chlorine compound.

The cyclic and/or acyclic aliphatic olefin used as a raw material in the present invention has at least one carbon-
It is an olefin with carbon double bonds. Specifically, cyclopentene, cyclohexene, cyclooctene, dicyclopentadiene, 1-hexene, 3-hexene, 1-heptane, 1-octene, 2-octene, 4-octene, 1-nonene,
1-decene, 5-decene, 6-decene, 1-dodecene, 1-tetradecene, 7-tetradecene, 1
Examples include -hexadecene, 8-hexadecene, 1-octadecene, 9-octadecene, and the like.

The oxygen-containing groups introduced by the action of peroxide on the double bonds of these olefins are adjacent diol groups,
These include an epoxy group, a hydroxyl group and an ether group, a hydroxyl group and an ester group, an ester group and an ether group, and various methods can be considered to introduce these oxygen-containing groups. For example, a method in which hydrogen peroxide is applied in a solvent system or a non-solvent system in the presence of a catalyst such as formic acid, mineral acid-carboxylic acid, tungstic acid, molybdic acid, vanadate acid, etc., or a catalyst using a combination thereof;
A method using inorganic peroxides such as pertungstic acid, permolybdic acid, permanganic acid, etc., a method using organic peroxides such as performic acid, peracetic acid, perbenzoic acid, perchlorobenzoic acid, etc., cumene hydroperoxide,
A method in which an organic peroxide such as t-butyl hydroperoxide is reacted in the presence of a catalyst such as a molybdenum, vanadium, or tungsten salt, or a method in which an aldehyde such as acetaldehyde or benzaldehyde is added to form a molecular form in the presence of a trace amount of a cobalt salt catalyst. A method of reacting while supplying oxygen to generate an organic peracid can be adopted. However, the method is not limited to the above method as long as it achieves the objective.

Catalysts suitable for the present invention contain at least cobalt,
It consists of one or more heavy metals selected from manganese and cerium and a bromine compound, or the heavy metal, a bromine compound, and a chlorine compound. These heavy metals may be in the form of simple elements, oxides, salts, or complexes. On the other hand, the bromine compound may be a bromine molecule, its acid, salt, oxyacid, or organic bromine compound. Particularly preferred are hydrogen bromide, ammonium bromide, sodium bromide, cobalt bromide, manganese bromide, cerium bromide, nickel bromide, tetrabromoethane, tribromoethane, and the like. As for the chlorine compound, those having the same form as the above-mentioned bromine compound can be used. "same form" used here
includes compounds that have the same compound form, such as simple molecules, oxides, salts, and complexes, as well as compounds that have a molecular formula in which the bromine atom is simply replaced with a chlorine atom, and are described below. "Same form" has the above meaning.

Examples of suitable catalysts include powdered cobalt metal and ammonium bromide, cobalt bromide, cobalt acetate and ammonium bromide, cobalt acetate and sodium bromide, cobalt acetate and potassium bromide, cobalt acetate and hydrogen bromide, acetic acid. These include cobalt and tetrabromoethane, manganese bromide, manganese acetate and hydrogen bromide, manganese acetate and ammonium bromide, manganese acetate and tetrabromoethane, cobalt bromide, nickel acetate and ammonium bromide, etc. These bromine compounds can partially replace chlorine compounds of the same type. Further, a catalyst comprising a combination of two or more heavy metals and a bromine compound, or a combination of two or more heavy metals, a bromine compound, and a chlorine compound is advantageous in that it eliminates the induction period and has a high reaction rate. Specific catalyst systems include, for example, cobalt bromide and manganese bromide, cobalt bromide and manganese acetate, cobalt acetate and manganese bromide, manganese acetate and cobalt acetate and ammonium bromide, manganese acetate and cobalt acetate and bromide. Hydrogen, cobalt bromide and cerium acetate, cobalt acetate and cerium bromide, manganese bromide and cerium acetate, cobalt acetate and manganese acetate and cerium acetate and ammonium bromide, cobalt naphthenate and manganese naphthenate and tetrabromoethane, cobalt acetyl Examples include acetate, manganese acetylacetate and hydrogen bromide, cobalt acetate, manganese acetate and sodium bromide, cobalt acetate, manganese acetate, cerium acetate and sodium bromide, cobalt naphthenate, manganese acetate and potassium bromide. Further, a part of these bromine compounds can be replaced with a chlorine compound of the same type. In addition, the present invention
It is not limited to the above examples.

The amount of heavy metals is the metal equivalent concentration per 1 raw material.
A suitable amount is 0.05 to 10 g/. If the amount is less than 0.05 g/l, a sufficient reaction rate cannot be obtained, and if it is more than 10 g/g/l, there will be disadvantages such as an increase in the expense required for the catalyst and an increase in side reactants. The appropriate amount of the bromine compound or the total amount of the bromine compound and chlorine compound used is 0.1 to 100 equivalents per heavy metal atom in terms of bromine atom. If the amount is less than 0.1 equivalent, a sufficient reaction rate cannot be obtained, and if it is more than 100 equivalents, the product may be contaminated with bromine or chlorine, and the cost required for the catalyst may increase, which is not preferable.

If the bromine compound or chlorine compound is accompanied by exhaust gas and exits the reaction system during the reaction, the reaction rate will be reduced, so it is preferable to carry out the reaction while adding the bromine compound or chlorine compound as appropriate. In this case, the additional amount is 1%/1% of the oxidation raw material in terms of bromine atoms.
h or less is sufficient.

A reaction solvent is not necessarily required, but when the melting point of the raw material is high or when a solvent is used to remove the heat of reaction, an organic compound that is inert to oxidation or relatively stable under the reaction conditions is used. For example, saturated monocarboxylic acids having about 2 to 10 carbon atoms are preferred;
Acetic acid is particularly suitable.

As the molecular oxygen used as the oxidizing agent, pure oxygen or industrial exhaust gas can be used, but the present invention is not limited to these, and any gas containing oxygen may be used, and from an industrial perspective, normal air is most suitable.

The reaction pressure is such that the total reaction pressure is 0 to 100 Kg/cm ² G, preferably 2 to 40 Kg/cm ² G, and the oxygen partial pressure is
0.1-10Kg/ ^cm2 is preferred. Furthermore, from a safety perspective,
It is desirable to operate so that the oxygen concentration in the exhaust gas from the reactor is 8% by volume or less.

The reaction temperature is 60-200°C, preferably 80-140°C. At temperatures lower than 60℃, the reaction rate is low;
On the other hand, if the temperature exceeds 200°C, the decomposition of the solvent and products into carbon dioxide will be severe, which is not preferable.

The concentration of water in the reaction solution is preferably kept at 15% or less. The produced water can be reacted while being removed from the system along with the exhaust gas, but it is also possible to react as it is without taking any particular means to remove the water. Although water accumulates when the solvent is used repeatedly, it can be used without removing water until the water concentration reaches 15% at the end of the reaction.

The method of the present invention is generally carried out as follows.

The product is obtained by reacting a peroxide such as hydrogen peroxide or an organic peracid to a cyclic and/or acyclic aliphatic olefin, which is a raw material, in a reactor equipped with a stirrer and equipped with a gas inlet and a gas outlet. A product containing an oxygen-containing group, a catalyst, and optionally a solvent are charged, replaced with air or pressurized, and heated to a predetermined temperature. During this temperature rising period, stirring and gas blowing are not necessarily required. Oxygen absorption depends on the type and concentration of catalyst, type and composition of raw materials, but generally 60~
Starting from 100℃. At the point when oxygen absorption begins, air is introduced and the reaction is carried out while maintaining a predetermined oxygen partial pressure. The exhaust gas may be cooled with water, and the resulting condensate may be returned to the reactor or taken out of the system.

The bromine compound can be reacted without being added after being charged at the start of the reaction, but if a higher reaction rate is desired, it is preferable to add the bromine compound little by little as the reaction progresses. In this case, a liquid such as tetrabromoethane is left as it is, and a solid such as ammonium bromide is dissolved in water or a solvent and is fed continuously or intermittently using a pump. After reacting for a predetermined time, it is cooled and the reactant is taken out. First, after distilling off the solvent used, the desired product can be obtained by distillation if the product is a monocarboxylic acid, or by distillation if the product is a dicarboxylic acid.
It can also be obtained by recrystallization using water or the like.

In addition to the above-mentioned stirring type reactor, any closed container capable of mixing gas and liquid, such as a bubble column or an artificial waterfall type, can be used. In addition, the reaction method is not limited to the batch method;
Continuous reactions are also possible. Raw materials, catalyst, and if necessary, a solvent are continuously supplied to the reactor, and while oxygen or oxygen-containing gas is blown into the reactor, the reaction product is withdrawn at a fixed residence time. At this time, there is no need to limit the feeding rate of the raw materials or solvent in order to maintain the raw materials. Even when part of the bromine compound is replaced with a chlorine compound, the reaction can be carried out in exactly the same manner.

In the conventional method described above, since oxidative cleavage was not possible except for adjacent diol groups, it was necessary to selectively diolize carbon-carbon double bonds in the raw material. In contrast, the method of the present invention uses a specific catalyst to introduce not only adjacent diol groups but also oxygen-containing substituents such as epoxy groups, hydroxyl groups and esters, hydroxyl groups and ether groups, and ester groups and ether groups. Carbon-carbon double bonds can be selectively oxidized and cleaved. Therefore, it is possible to obtain an intermediate raw material that is oxidatively cleaved by molecular oxygen very easily, and at the same time, it is possible to obtain the target aliphatic material in a very high yield with respect to the raw material cyclic and/or acyclic aliphatic olefin. group carboxylic acids can be obtained.

Furthermore, the oxidative cleavage method of the present invention does not require the addition of expensive peracetic acid, ketones, aldehydes, or the like. Furthermore, when conducting continuous reactions, there are many industrial advantages such as there is no need to particularly purify raw materials or solvents, and there is no need for special measures such as restricting their supply so that the reaction does not stop. have

Examples will be shown below and specifically explained in detail.

Example 1 100 g of acetic acid and 0.4 g of concentrated sulfuric acid were added to 160 g of 1-decene, and 68 g of 60% hydrogen peroxide was added to this at 65-70°C.
The mixture was added dropwise over a period of time, and the reaction was further continued at this temperature for 5 hours. After adding 0.2g of sodium hydroxide to the reaction mixture,
Acetic acid, water, etc. were distilled off under reduced pressure, and the residue was washed with water. The obtained oily substance has an iodine value of 2, an adjacent hydroxyl value of 140,
The vicinal hydroxyl value after saponification was 293. Next, the above oily substance was air oxidized. In a titanium autoclave with an internal volume of 500 ml, add 100 g of the above oily substance and acetic acid.
100 g, cobalt bromide [CoBr ₂ 6H ₂ O] 0.66 g and manganese acetate [Mn (OOCCH ₃ ) ₂ 4H ₂ O] 0.50
g, air was introduced, and the reaction pressure was 25Kg/cm ²
The mixture was heated and stirred while maintaining the temperature at G (oxygen partial pressure 2 Kg/cm ² ). Oxygen absorption began at 80°C. The reaction temperature is 100°C. 1 hour and 2 hours after reaction
1 ml of 20% aqueous ammonium bromide solution was added to each. After a total of 3 hours of reaction, almost no oxygen absorption was observed. After the reaction product was cooled, it was distilled under reduced pressure to remove acetic acid, and further distilled under reduced pressure to obtain 71 g of distillate. As a result of analysis by gas chromatography, this distillate contained 6% by weight of short chain fatty acids having 4 to 7 carbon atoms, 6% by weight of caprylic acid, and 88% by weight of pelargonic acid.
It was in weight%. The yield of pelargonic acid corresponds to 85 mol % based on the raw material 1-decene.

Example 2 Add 39 g of 88% formic acid to 123 g of cyclohexene,
102 g of 60% hydrogen peroxide was added dropwise at 65 to 70°C over 1 hour, and the mixture was reacted at 80°C for 6 hours. Formic acid, water, etc. were distilled off from the reaction product under reduced pressure to obtain 202 g of an oily substance.
The obtained oily substance has an iodine value of 4 and an vicinal hydroxyl value.
407, and the vicinal hydroxyl value after saponification was 658. next,
In the same reactor as in Example 1, 100 g of the above oily substance,
100g of acetic acid, cobalt acetate [Co(OOCCH ₃ ) ₂ .
4H ₂ O] 0.50g Cerium acetate () 0.63g and 47
% hydrobromic acid, and while blowing air at 100℃, the reaction pressure was 25Kg/cm ² G (oxygen partial pressure 2Kg/
cm ² ). After 2 hours of reaction, 2 ml of 20% ammonium bromide aqueous solution was added, and after further reaction for 2 hours, almost no oxygen absorption was observed. After acetic acid and water were distilled off from the reaction mixture, it was distilled under reduced pressure to obtain 138 g of solid distillate. As a result of analysis by gas chromatography, the composition of this distillate was 3% by weight of succinic acid, 10% by weight of glutaric acid,
Adipic acid was 87% by weight. The yield of adipic acid corresponds to 82 mol% based on the raw material cyclohexene.

Example 3 100 g of an oily substance obtained by operating 160 g of 1-decene in the same manner as in Example 1 was placed in a titanium autoclave, and 100 g of acetic acid and cobalt bromide [ _CoBr2 .
6H ₂ O〕0.33g, cobalt acetate〔Co
(OOCCH ₃ ) ₂・4H ₂ O] 0.25 g, manganese acetate [Mn (OOCCH ₃ ) ₂・4H ₂ O] 0.50 g, and concentrated hydrochloric acid 0.17
Add g. While blowing air into this at 100℃,
The reaction was carried out at a reaction pressure of 25 kg/cm ² G (oxygen partial pressure 2 kg/cm ² ). 10% after 1 hour and 2 hours after starting the reaction
Add ammonium chloride aqueous solution 1 ml at a time to make a total of 3
After time reaction, almost no oxygen absorption was observed. After the acetic acid was distilled off, 70 g of distillate was obtained by distillation under reduced pressure. Analysis by gas chromatography revealed that the distillate contained 6% by weight of short chain fatty acids having 4 to 7 carbon atoms, 7% by weight of caprylic acid, and 87% by weight of belargonic acid. The yield of pelargonic acid corresponds to 85 mol% based on 1-decene.

Comparative Example 1 100 g of an oily substance obtained by operating 160 g of 1-decene in the same manner as in Example 1, 100 g of acetic acid, 0.50 g of cobalt acetate [Co(OOCCH ₃ ) _{2.4H 2} O], manganese acetate [Mn(OOCCH ₃ ) 0.50 g of ₂・4H ₂ O] was placed in the same autoclave as in Example 1, and while blowing air at 100°C, the reaction pressure was 25 Kg/cm ² G (oxygen partial pressure 2
Kg/cm ² ) for 3 hours. After the reaction was completed, acetic acid was distilled off, and 19 g of distillate was obtained by distillation under reduced pressure. Analysis by gas chromatography revealed that the distillate contained 7% by weight of short chain fatty acids having 4 to 7 carbon atoms, 19% by weight of caprylic acid, and 74% by weight of pelargonic acid. The yield of pelargonic acid corresponds to 20% by mole based on 1-decene as a raw material.

As described above, when a known catalyst containing no bromine compound or chlorine compound is used, the yield of aliphatic carboxylic acid obtained is extremely low.

Claims (1)

[Claims] 1. An oxidation product obtained by reacting a peroxide with a cyclic and/or acyclic aliphatic olefin having at least one unsaturated bond in the carbon chain is selected from at least cobalt, manganese, and cerium. A method for producing an aliphatic carboxylic acid, which comprises carrying out oxidative cleavage with molecular oxygen in the presence of one or more heavy metals and a bromine compound, or a catalyst consisting of the heavy metal, a bromine compound, and a chlorine compound.