JPS6234028B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing ethylidene diacetate, which is characterized by subjecting acetaldehyde, methyl acetate, and carbon monoxide to a carbonyl reaction.

Conventionally, methods for synthesizing ethylidene diacetate include a method using acetylene and acetic acid as raw materials, and a method of synthesizing ethylidene diacetate by reacting acetaldehyde and acetic anhydride. On the other hand, a method has recently been proposed in which ethylidene diacetate is synthesized by using methyl acetate or dimethyl ether as a raw material and subjecting carbon monoxide and hydrogen to a catalytic reaction in the presence of a catalyst (Japanese Patent Application Laid-Open No. 1983-1983-1).
115409). In summary, this proposal involves the synthesis of ethylidene diacetate from methyl acetate or dimethyl ether in the presence of a halide in a catalyst system using rhodium or palladium as a main catalyst and a specific organic or inorganic compound as a co-catalyst. This disclosed method uses synthesis gas and is an attractive method from the viewpoint of raw materials, but since this reaction is a concerted reaction of carbonylation reaction using carbon monoxide and reduction reaction using hydrogen, For example, there is a strong possibility that impurities such as ethyl acetate and propionic acid will be produced as by-products, and acetic acid will also be produced as a by-product even in the stoichiometric reaction formula. Furthermore, the yield of ethylidene diacetate cannot be said to be satisfactory.
In view of the above points, the present inventors continued their intensive research on a rational method for producing ethylidene diacetate and completed the present invention.

That is, the present invention provides a method for treating acetaldehyde, methyl acetate, and This is a method for producing ethylidene diacetate, which is characterized by reacting carbon oxide.

Although the detailed reaction mechanism of the carbonylation reaction of the present invention is not clear, it can be expressed as a comprehensive reaction by the following chemical reaction formula.

CH ₃ CHO + CH ₃ COOCH ₃ + CO → CH ₃ CH (OCOCH ₃ ) _2The reaction represented by the above chemical formula uses one or more metals of palladium, rhodium, and nickel as the main catalyst, and this is assisted by bromide, iodide, or a mixture thereof. By using it as a catalyst, the reaction can proceed suitably.

Metal catalysts can be utilized in any type. Some examples include PhX ₃ , RhX ₃・3H ₂ O,
[RhX (CO) ₂ ] ₂ , Rh ₆ (CO) ₁₆ , RhX (PPh ₃ ) ₃ ,
Rh( _SnCl3 )( _PPh3 ) ₃ , RhI(CO)( _SbPh3 ) ₂ ,
RhH(CO)(PPh3) _{3 ,} Rh(AcAc) ₃ , Rh
(AcO)( _PPh3 ) ₂ , Rh metal, _Rh2 (CO) ₃ , RhX
(CO)( _PPh3 ) ₂ , RhCl(CO)( _AsPh3 ) ₂ , RhX
(CO) [P(n- _{C4H9 ) 3} ] ₂ , [Rh _{( C2H4} ) _2Cl ] ₂ ,
[Rh(AcO) ₂ ] ₂ , RhCl(CO) [P(OPh) ₃ ] ₂ ,
{Rh[P(OPh) ₃ ] ₄ } ₂ , RhCl(PPh ₃ ) ₂
(CH ₃ I) ₂ , [RH(CO) ₂ X] [(n-C ₄ H ₉ ) ₄ N],
[Rh ₂ O ₂ X ₄ ] [(n-C ₄ H ₉ ) ₄ As] ₂ , [Rh(CO)I ₄ ]
[(n- _{C4H9 ) 4P} ] _{, K4Rh2X2} ( _SnX3 ) ₄ , _{PdX2 ,}
[Pd(CO)X ₂ ] ₂ , [Pd(PPh ₃ ) ₂ ]X ₂ , [Pd
(PPh ₃ )] ₂ (CO)Br, (PdX ₄ ) [(n-C ₄ H ₉ ) ₄ P],
Pd _[ ((n- _C4H9 ) _3P ](CO) _Cl2 , PdCl( _PPh3 ) ₂
(SnCl ₃ ), Pd [(n-C ₄ H ₉ ) ₃ P] ₂ I ₂ , Ni metal,
NiX ₂ , NiX ₂・3H ₂ O, Ni(CO) ₄ , Ni(CO) ₂
(PPh ₃ ) ₂ , Ni(AcAc) ₂ , CoI ₂ , [Co(CO) ₄ ] ₂ ,
HCo(CO) ₄ , _FeI2 , Fe(CO) ₅ , _H2Fe (CO) ₄
(X in the above formula is Cl, Br or I, Ph is a phenyl group, OPh is a phenoxy group, AcO is an acetoxy group,
AcAc each represents an acetylacetonate group. ) can be given.

Of course, it is also possible, and sometimes advantageous, to use a combination of these metal catalysts.

The halide used as cocatalyst is bromide or iodide or a mixture thereof, preferably iodide. Typically, the halides are present mostly in the form of alkyl halides such as methyl iodide, acid halides such as acetyl iodide, hydrogen halides such as hydrogen iodide, or any mixture thereof, and are can be introduced into the phase reaction medium. However, it is sufficient to introduce into the liquid phase such substances that any one or more of these halides, ie alkyl halides, acid halides or hydrogen halides, are formed in the reaction medium. Substances which react with other components therein in the reaction medium to form alkyl halides, acid halides or hydrogen halides include inorganic halides such as alkali metal and alkaline earth metal salts and elemental iodine and bromine. be.

Furthermore, in the present invention, an organic accelerator is also used.

Suitable organic promoters are non-hydrocarbons that are capable of forming coordination compounds with the metal catalyst and that contain in their molecular structure one or more pairs of electrons that can form coordination bonds with the catalytic metal. This type of organic promoter can be introduced into the reaction zone at the same time as the reactants, or a metal coordination chain formed by bonding with the catalytic metal can be introduced into the reaction zone.

Suitable organic promoters are organic compounds of nitrogen, phosphorus, antimony and arsenic. Some of these are expressed by the following formula.

(M is N, P, Sb or As, R ₁ , R ₂ ,
R ₃ is hydrogen or an alkyl, cycloalkyl, or aryl group each preferably having 10 or less carbon atoms, which may be the same or different from each other. ) This example is given by way of illustration only and not limitation: monomethylamine, dimethylamine, trimethylamine, dimethylethylamine, diethylamine, tri-iso-propylamine, tri-n-
Propylamine, tri-n-butylamine, tri-tert-butylamine, aniline, dimethylaniline, diethylaniline, etc. or tri-n-propylphosphine, tri-iso-propylphosphine, tri-n-butylphosphine, tri- tert
-butylphosphine, tricyclohexylphosphine, ethylenebis(diphenylphosphine) and triphenylphosphine, or trimethylarsine, triethylarsine, triethylarsine, tri-iso-propylstibin, ethyl-di-iso-propylstidine Vin, tricyclohexylarsine, triphenylstibine, tri(o
-tolyl)-stibine, phenyldi-iso-propylarsine, phenyldiamylstibin, diphenylarsine, tris(diethylaminomethyl)
stibine, bis(diphenylarsino)ethane,
bis(di-iso-propylarsino)hexane,
Examples include bis(diethylstivino)pentane.

Further, organic nitrogen compounds other than those mentioned above, and organic nitrogen compounds containing oxygen or phosphorus atoms together with nitrogen, can also be suitably used as the organic promoter. Non-limiting examples _include , for example, pyrrole, pyrrolidine, piperidine _, pyrimidine, picolins, pyrazine and N-lower alkyl substituted derivatives of these, such as pyrazine and N-methylpyrrolidine, benzotriazole, piperazine, N-methylpiperazine, N-ethylpiperazine, 2-methyl-N-
Methylpiperazine, 2,2-dipyridylmethyl-substituted 2,2-dipyridyl, 1,4-diazabicyclo[2,2,2]octane, methyl-substituted 1,4-
Diazabicyclo[2.2.2]octane, purine, 2-aminopyridine, 1.10-phenanthroline, methyl-substituted 1.10-phenanthroline,
2-(dimethylamino)pyridine, 2-(dimethylamino)-6-methoxyquinoline, 7-chloro-
1,10-phenanthroline, 4-triethylsilyl-2,2'-dipyridyl, 5-(thiaventyl)-
1,10-phenanthroline, pyridine, 2,4-
dimethylpyridine, 2,6-dimethylpyridine,
Heterocyclic nitrogen compounds such as 2,4,6-trimethylpyridine and imidazole, and N,N,N',N'-tetramethylethylenediamine, N,N,N',
N'-tetraethylethylenediamine, N・N・
N', N'-tetra-n-propylethylenediamine, N, N, N', N'-tetramethylmethylenediamine, N, N, N', N'-tetraethylmethylenediamine, N, N, N', N Examples include diamines such as '-tetraiso-butylmethylenediamine, and nitriles such as acetonitrile, propionitrile, adiponitrile, and benzonitrile. Suitable organic promoters containing oxygen or phosphorous atoms along with nitrogen also include hydroxy or carboxy substituted compounds of the organic nitrogen compounds, such as
2-hydroxypyridine, methyl-substituted 2-hydroxypyridine, picolinic acid, methyl-substituted picolinic acid, 2,5-dicarboxypiperazine, ethylenediaminetetraacetic acid, 2,6-dicarboxypyridine, 8-hydroxyquinoline, 2- Carboxyquinoline, cyclohexane-1,2-diamine-N・N・N′・N′-tetraacetic acid, tetramethyl ester of ethylenediaminetetraacetic acid and its salts, ammonium salts such as ammonium acetate, acetamide, N・N′- Carboxylic acid amides such as dimethylacetamide, acetanilide, N-methyl-N-phenylacetamide, N.
Amino acids such as N-dimethylglycine and N·N-diethylglycine, furthermore, 1-methyl-2-pyrrolidinone, 4-methylmorpholine, N·N·
N′・N′-tetramethylurea, iminodiacetic acid, N
-Methyliminodiacetic acid, nitrilotriacetic acid,
Also included are phosphine iminium salts such as triphenylphosphine iminium chloride.

Among the above groups of compounds, organic promoters containing trivalent nitrogen and phosphorus are particularly preferred.

The amount of the group metal used as the main catalyst in the present invention is 10 ^-6 to 5 mol, preferably 10 ^-4 to 1 mol, more preferably 10 ^-3 per 1 mol based on the total volume of the liquid phase reaction medium. Select from the range of ~0.5 mol. The amount of the halogen atom-containing substance used as a promoter is 10 ^-6 to 15 mol, preferably 10 ^-5 to 5 mol, more preferably 10 ^-4 per total volume of the liquid phase reaction medium, based on halogen atoms. It is used in the range of ~3 mol. Additionally, the amount of organic or inorganic promoter used will depend on the amount of Group metal catalyst in the reaction zone, but will usually range from 10 ^-6 to 10 moles per mole, based on the total volume of the liquid reaction medium. 10 ^-4 ~5
A range of moles is chosen.

The reaction temperature for carrying out the method of the present invention is suitably in the range of 20 to 500°C, preferably 30 to 350°C, more preferably 40 to 250°C. The total reaction pressure is also not a critical parameter in the preparation, provided that it is sufficient to maintain the liquid phase reaction medium in the liquid phase and to maintain carbon monoxide and hydrogen at appropriate partial pressures. The preferred partial pressure of carbon monoxide is 0.5 to 350 atmospheres, optimally 1 to 350 atmospheres.
The partial pressure is 300 atmospheres, more preferably 3 to 250 atmospheres, but a wider partial pressure range of 0.05 to 1000 atmospheres is also acceptable. The carbon monoxide used does not necessarily have to be of high purity; hydrogen, carbon dioxide,
It may be contained in methane, nitrogen, rare gas, etc.
Among these, hydrogen in the reaction gas tends to stabilize the catalyst, and in many cases has a favorable influence on the progress of the reaction. Moreover, extremely low purity carbon monoxide is undesirable because it increases the pressure in the reaction system.

Acetaldehyde and methyl acetate, which are the raw materials of the present invention, can also be supplied by a method in which the basic raw materials are not derived from petroleum products such as ethylene, for example, by the reaction of methanol and synthesis gas (for example, Japanese Patent Publication No. 48-2525, Kaisho 51-149213, Tokukaisho
52-136110, Japanese Patent Application Publication No. 52-136111, etc.). in this case,
Methanol, dimethyl acetal,
Although it is expected that impurities such as acetic acid will be mixed in, the reaction can proceed suitably by allowing the above-mentioned impurities as long as they do not disturb the overall balance of the reaction.

The molar ratio of acetaldehyde to methyl acetate, which is the raw material of the present invention, can be used within a wide range, but especially when the intention is to improve the conversion rate of acetaldehyde, the amount of methyl acetate to be used should be determined according to the stoichiometric ratio expressed by the above formula. It is better to use excess rather than quantity. The presence of water in reaction raw materials is a common phenomenon, but carbon monoxide, acetaldehyde,
Methyl acetate tolerates the presence of small amounts of water, which is often present in commercially available reactants, without causing any problems. However, the presence of 10 mol % or more of water in one or more of the reaction raw materials used in the present invention should generally be avoided, as introducing too much water into the reaction system tends to lead to decomposition of the product. In this respect, it is desirable that the water content be 5 mol% or less, more preferably 3 mol% or less. Since water is not a reaction product, maintaining near-anhydrous conditions within the liquid phase reaction medium is easily achieved by maintaining the necessary reactants introduced into the reaction zone as well as the reaction working fluid in an appropriately dry state. will be achieved. In the method of the present invention, since the raw material methyl acetate itself also serves as a reaction solvent, it is not necessary to use a solvent, but it is preferable to use one. Commonly used solvents include organic acids such as acetic acid, propionic acid, butyric acid, octanoic acid, phthalic acid, and benzoic acid, methyl acetate, ethyl acetate, ethylene glycol diacetate, propylene glycol diacetate, dimethyl adipate, and methyl benzoate. , ethyl benzoate, dimethyl phthalate,
Organic acid esters such as diethyl phthalate, dioctyl phthalate, phenyl acetate, tolyl acetate, hydrocarbons such as dodecane, hexadecane, benzene, naphthalene biphenyl, triphenyl phosphate, tricresyl phosphate, dibutyl phenyl phosphate ate, inorganic acid esters such as tetramethyl orthosilicate and tetrabutyl silicate, aromatic ethers such as diphenyl ether,
Acetone, methyl ethyl ketone, dibutyl ketone, methyl isobutyl ketone, acetophenone,
Examples include ketones such as benzophenone.

As mentioned above, since the present invention uses methyl acetate as the majority of the raw materials, it is a preferred embodiment to use the raw material methyl acetate itself, its derivative acetic acid, or a mixture thereof as a solvent. These solvents also tend to stabilize the catalyst and reaction system, increasing the selectivity and yield of the desired product.

The method of the present invention can be carried out in a batch, semi-batch or continuous manner, but the semi-batch and continuous flow reaction formats maintain a low concentration of raw material acetaldehyde, which has the property of causing a polymerization reaction, in the reaction system. This is a particularly preferred embodiment. For industrial implementation, a continuous flow reaction method is preferred.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 A reaction vessel was charged with 0.341 g of rhodium trichloride, 1.36 g of triphenylphosphine, 28.4 g of methyl iodide, and 60 ml of methyl acetate as a solvent, and then the reaction vessel was replaced with carbon monoxide and pressurized. The reaction temperature was raised to 150°C and maintained at this temperature. total pressure
8.8 g of acetaldehyde and 14.8 g of methyl acetate were continuously added to a reaction vessel pressurized with carbon monoxide to 90 Kg/cm ² G (approximately 80 Kg/cm ² G partial pressure of carbon monoxide).
It was press-fitted in time. After the injection, the reaction was continued for another 2 hours. After cooling, the reaction solution was analyzed and found to contain 21.8 g of ethylidene diacetate. This corresponds to 74.7% of the theoretical yield of raw material acetaldehyde.

Example 2 Chlorocarbonylbis(triphenylphosphine)rhodium 0.35g, lithium acetate 2.0g, methyl iodide 14.2g and methyl acetate 60ml as solvent
into the reaction vessel. After replacing the reaction vessel with carbon monoxide and pressurizing it, the reaction temperature is raised to 165°C and maintained at this temperature. Total pressure 50Kg/cm ² G (approximately 40Kg/cm ²
8.8 g of acetaldehyde and 14.8 g of methyl acetate were continuously pressurized over 2 hours into a reaction vessel pressurized with carbon monoxide (partial pressure of carbon monoxide). After the injection, the reaction was continued for an additional 2 hours. After cooling, the reaction solution was analyzed and found to be 19.6% ethylidene diacetate.
g was included. This corresponds to 67.1% of the theoretical yield of raw material acetaldehyde.

Example 3 A reaction vessel was charged with 1.0 g of palladium acetate, 5.0 g of triphenylphosphine, 25.5 g of methyl iodide, and 60 ml of methyl acetate as a solvent, and then the reaction vessel was replaced with carbon monoxide and pressurized, followed by reaction. The temperature was increased to 150°C and maintained at this temperature. Total pressure 100
8.8 g of acetaldehyde and 14.8 g of methyl acetate were continuously pressurized over 2 hours into a reaction vessel pressurized with carbon monoxide to Kg/cm ² G (carbon monoxide partial pressure of about 90 Kg/cm ² G). After the injection, the reaction was continued for an additional 2 hours. After cooling, the reaction solution was analyzed and found to contain 14.1 g of ethylidene diacetate. This corresponds to 48.3% of the theoretical yield of raw material acetaldehyde.

Example 4 2.57 g of nickel acetylacetone, tri(n-
butyl) phosphine 4.1g, methyl iodide 21.3
g, and 30 ml of methyl acetate and 50 ml of acetic acid as solvents.
was charged into a reaction vessel, and then the reaction vessel was replaced with carbon monoxide, and after pressurization, the reaction temperature was raised to 175°C and maintained at this temperature. Total pressure 53Kg/cm ² G (approximately 40
8.8 g of acetaldehyde is placed in a reaction vessel pressurized with carbon monoxide (partial pressure of carbon monoxide in kg/cm ² G).
14.8 g of methyl acetate was continuously pressurized over a period of 2 hours.
After the injection, the reaction was continued for an additional 2 hours. After cooling,
Analysis of the reaction solution revealed that it contained 15.0 g of ethylidene diacetate. This corresponds to 51.4% of the theoretical yield of raw material acetaldehyde.

Example 5 Rhodium trichloride 0.341g, 2.6-lutidine 0.56
g, 21.3 g of methyl iodide, and 30 ml of methyl acetate and 50 ml of acetic acid as solvents were charged into a reaction vessel.Then, the reaction vessel was replaced with carbon monoxide, and after pressurization, the reaction temperature was raised to 165°C. maintained. Total pressure 70Kg/cm ² G (carbon monoxide partial pressure of approximately 60Kg/cm ² G)
8.8 g of acetaldehyde and 14.8 g of methyl acetate were continuously pressurized over 2 hours into a reaction vessel pressurized with carbon monoxide. After the injection, the reaction was continued for another 2 hours. After cooling, the reaction solution was analyzed and found to contain 19.1 g of ethylidene diacetate. This corresponds to 65.4% of the theoretical yield of raw material acetaldehyde.

Claims (1)

[Claims] 1 Halides, which are iodides or bromides,
and one of palladium, rhodium and nickel
A process for producing ethylidene diacetate, which comprises reacting acetaldehyde, methyl acetate and carbon monoxide under substantially anhydrous conditions in the presence of a catalyst consisting of one or more metals and an organic promoter.