JPS59144730A - Preparation of acetic anhydride - Google Patents

Abstract

PURPOSE:To obtain acetic anhydride, by reacting methyl acetate or dimethyl ether with CO in the presence of a catalyst containing a compound such as diphenyl(diethylamino)phosphine, n-butyliminotriphenylphosphorane, etc., Ni and I. CONSTITUTION:Methyl acetate and/or dimethyl ether is reacted with CO in the presence of a catalyst containing a compound shown by the formula I or formula II(R<1>-R<5> are hydrocarbon group which may be substituted, with the proviso that R<1> and R<2>, and R<3> and R<4> may form ring; X<1> is N, P, or As; n is 1 or 2) or its salt, and Ni and I, to give acetic anhydride. Ni, a main catalytic component, may be any of metal Ni, or a compound such as oxide, hydroxide, etc., and its amount used is 0.001-0.05g atom based on 1mol dimethyl ether and methyl acetate. I is a reaction promotor, and its amount used is 0.1-100mol based on 1g atom Ni.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing acetic anhydride. Acetic anhydride is a very important chemical product industrially as a raw material for producing acetyl cellulose, and has conventionally been produced industrially by reacting ketene obtained by thermal decomposition of acetic acid with acetic acid.

Several publications are known regarding the production of acetic anhydride by carbonylation of dimethyl ether and/or methyl acetate using metals from group 1 of the periodic table - iodine catalysts. i.e. US Patent λ, 729.63/ and German Patent 933. /'Ig describes a method for producing acetic anhydride by carbonylating dimethyl ether or methyl acetate using a catalyst consisting of nickel, phosphonium halide, and ammonium halide. German patent 92/93g contains nickel and...
A method has been proposed in which a similar reaction is carried out in the presence of hydrogen using a catalyst comprising rogene. US Patent 3,0/
No. 9, No. 9, discloses a method using a catalyst consisting of nickel, a halogen, and a polyfunctional ligand. Here, as the polyfunctional ligand, a 7th amino alcohol,
Examples include a 7th class aminocarboxylic acid, a hydroquinecarboxylic acid, a kutocarboxylic acid, a diketo compound, a dihydroxy compound, a dinitrile compound, and a 7th class diamine.

Tokuko Akira 3-g/”l and U.S. patents y, o
O, 2, No. 77 discloses a method for producing acetic anhydride using a catalyst consisting of nickel, bromine or iodine, chromium, and tin. Special Publication Showa 3.1-116g/Left and US Patent Da, 002. For Otsu 7g, there is a method in which a reaction is carried out in a carboxylic acid solvent using a halogen compound of nickel, halogen, chromium, amine or nickel, and a catalyst consisting of amine, phosphine, or arsine. Or using a catalyst made of acyl iodide and an alkali metal salt, alkaline earth metal salt, phosphonium iodide, sulfate or ammonium iodide, etc. A catalyst made of sulfyl or acyl iodide and an alkali metal salt or alkaline earth metal salt proposed a method of conducting the reaction in a carboxylic acid amide solvent using
Each has its own characteristics, and their academic value is evaluated as extremely great. However, several problems still remain to be overcome in order to implement these methods industrially.

In other words, Konera's catalyst has low activity;
Those that are too thin are unsuitable for use in actual industrial processes because their catalyst components are multi-component and complex, and those that are too thin may form insoluble precipitates in the reaction solution. There are drawbacks.

The present inventors took the above facts into consideration, and found that the catalytic activity is high,
As a result of intensive study on a method for producing acetic anhydride that is excellent as an industrial process, the inventors discovered that carrying out the reaction using a catalyst containing nickel, iodine, and a specific compound met the above objectives, and thus arrived at the present invention. did.

That is, the present invention provides (a) the following general formula [1] and ~: [■
] In the presence of at least seven compounds selected from the compounds represented by and salts thereof, and a catalyst containing (ro)nickel and 0→iodine, methyl acetate and/or dimethyl ether are reacted with carbon monoxide. A method for producing acetic anhydride (in the above formula, R1 to R8 may have a substituent)
- indicates a hydrocarbon group. However, R1, t, - and R2 as well as R3 and R4 may form a ring. Xl represents a nitrogen, phosphorus or arsenic atom, X2 represents a phosphorus or arsenic atom, and Y represents a nitrogen, phosphorous or arsenic atom. In addition, n indicates an integer of / or -. ).

The present invention will be explained in more detail below.

In the method of the present invention, it is essential to use nickel as the main catalyst component. As a nickel component,
Both metallic nickel and nickel compounds can be used. Examples of the nickel compound include oxides, hydroxides, inorganic acid salts, organic acid salts, and organic and inorganic complex compounds.

Specific examples include nickel oxide, nickel hydroxide,
Nickel fluoride, nickel chloride, nickel bromide, nickel iodide, nickel sulfate, nickel nitrate, nickel carbonate, nickel tetrafluoroborate, nickel acetate, nickel oxalate, bis(acetylacetone)nickel, tetracarbonylnickel, tricarbonyl ( ) 'J n-butylphosphine)nickel, dicarbonyl(triphenylphosphine)nickel, tetrakis(triphenylphosphine)nickel, μm(dinitrogen)bis[bis(tricyclohexylphosphine)nickel], dicarbonylbis(isonoanide t -butyl)nickel, (η-ethylene)bis(triphenylphosphine)nickel, his(
Acrylonitrile) nickel, bis(η-cyclooctadiene) nickel, bistriphenylphosphine bipyridyl nickel, bromotris(triphenylphosphine) nickel, dicarbonylbis(η-cyclopentadienyl) nickel, cifromobis(triphenylphosphine) nickel, Chlorohydridobis() IJcyclohexylphosphine)nickel, bis(η-cyclopentadienyl)nickel, chloro(phenyl)bis(triphenylphosphine)nickel, tetrabromobis(tetra n-butylammonium)nickel, tetrabromobis( bistrinoenylphosphineiminium) nickel, etc.

The amount of nickel used is 0.0000/~/ per mole of dimethyl ether and methyl acetate, which are the reaction thick phases.
It is necessary to use iodine, preferably from 0.000 to .theta., per gram atom, more preferably from 0.007 to iodine. Iodine may be a simple substance or a compound, and specific examples include simple iodine, hydrogen iodide, alkali metal iodides such as sodium iodide and potassium iodide, and magnesium iodide. Alkaline earth metal iodides, ammonium salts such as tetra-n-butylammonium iodide and diethylpyrrolidinium iodide, phosphonium salts such as tetraphenylphosphonium iodide and tetra-n-propylphosphonium iodide, and bistriphenylphosphine iodide. iminium salts such as minium, methyl iodide, ethyl iodide,
Examples include alkyl iodides such as iodobenzene and aryl iodides.

The amount of iodine used is 0.0% in terms of nickel/gram ◆ atom. /~/, 000 mol, preferably 0.
It is 7 to 100 moles.

In the method of the present invention, seven or more compounds selected from compounds represented by the following general formula CI) or [formula] or salts thereof are further used.

In the above formula, R'' to R8 represent a hydrocarbon group such as an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group that may have a substituent. As the alkyl group, 01 to C6 are preferable. R2, R3 and R4 may form a ring. When forming a ring, a +-A membered ring saturated group or unsaturated group is preferable. X' represents nitrogen, phosphorus or arsenic atom, represents a phosphorus or arsenic atom, and Y represents a nitrogen, phosphorus, or arsenic atom.However, X2 and Y
may be the same. n represents/or an integer of λ.

Examples of the compound represented by [I] include the following.

diphenyl(diethylamino)phosphine diphenyl(
di-n-butylamino)phosphinediphenyl(piperidino)phosphinediphenyl(diphenylamino)phosphinedi-n-butyl(diethylamino)phosphinedi-n-butyl(diphenylamino)phosphinediphenyl(diphenylphosphino)arcinephenylbis(diethylamino)phosphinetetra Examples of the compound represented by phenyldiphosphinetetraphenyldiarsine [■] include the following.

n-Butyliminotriphenylphosphorane Phenyliminotriphenylphosphorane Phenyliminotri n-butylphosphorane n-butyliminotriphenylbosphorane The general formula [■] and [older compound] may be salts. Examples of the salt include addition salts of hydrogen halides and addition salts of argyl halides. As the alkyl halide, 01 to C6 alkyl groups are preferable.

The amount of these compounds to be used is 0.00% for every 7 gram atom of nickel. / to /, 000 mol, preferably 7 to 700 mol.

In the method of the invention, the use of a solvent is not an essential condition. However, it is also possible to use a solvent for the purpose of smoothly carrying out the reaction.

As the reaction solvent, the following can be used. For example, ethers such as diethyl erthyl, anisole, tetrahydrofuran, ethylene glycol dimethyl ether, and dioxane, ketones such as acetone, methyl ethyl ketone, and acetophenone, alcohols such as methanol, ethanol, n-butanol, benzyl alcohol, phenol, ethylene glycol, and diethylene glycol. carptatonic acids such as formic acid, acetic acid, propionic acid, and toluic acid; esters such as methyl acetate, r1-bunal acetate, and benzoic acid; aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and tetralin;
Aliphatic hydrocarbons such as Yl-hexano, n-octane, cyclo-, and xane, nohalosaponified hydrocarbons such as dichloromethane, trichloroethane, and chlorobenzene, di-l-ro compounds such as nitromethane and nitrobenzene, triethylamine, +-lyn-butylamine , benzyldimethylamine, pyridine, alpha-pyridine, ---hydroxypyridine, etc.?
grade amine, N, N-dimethylformamide, N, 14~
Dimethylacetamide, carboxylic acid amide such as N-methylpyrrolidone, hexamethylphosphoric triamide, N, N'
- to dimethyl, other amides such as hexamethylsulfonic acid amide, imidazolitone, N, N, N, N-tetramethylurea axons, sulfones such as dimethylsulfone, tetramethylene sulfone, dimethylformoquine, etc. , sulfoxides such as di-11-phenyl sulfoxide, lactones such as γ-butyrolactone and ε-caprolactone, polyethers such as tetraglyme and 7g-crown-O, nitriles such as acetonitrile and benzonitrile, dimethyl ether-1. , carbonate esters such as ethylene carbonate, etc. Among the above solvents, aprotic polar solvents, namely amines, amides, ureas, sulfones, sulfoxides, lactones, polyethers,
Nitriles and carbonate esters are preferably used, and polar solvents with a dielectric constant of 20 or more are particularly desirable.

In order to produce acetic anhydride by the method of the present invention, a solvent, dimethyl ether and/or methyl acetate as reaction raw materials, and a catalyst may be charged into a reaction vessel, and -carbon oxide may be supplied thereto by a submerged gas blowing method. . - Carbon oxide may be pure or diluted with a gas inert to the reaction, such as nitrogen or carbon dioxide. Further, it is acceptable for hydrogen to be mixed in in a small amount, but if it is present in a large amount, by-products will be produced, so it is preferable to suppress its concentration in the reaction system to 20% (by volume) or less.

The reaction temperature is usually ! iθ~330℃, preferably 100
~λ is 0°C. The partial pressure of carbon monoxide in the separated reaction system is
Usually 70-300 KP/ca, preferably /3
~/θ OK? /cnf. Of course, it is not impossible to carry out the process at lower or higher pressures. But/K? /cr! Lower pressures may be impractical.

The time required for the reaction can vary greatly depending on the conditions, but in a batch reaction it is preferably 70 hours or less from an industrial perspective.

According to the method of the present invention, acetic anhydride can be produced in high yield.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Example/ In a titanium autoclave with an internal volume of 〇〇ml, 50 mmol of methyl acetate and bis(acetylacetone) were added.
Nickel, 2.0 mmol, methyl iodide, 20 mm
ol, diphenyl(diethylamino)phosphine (Ph
2P-NEt2) b, Ommol, and a solvent γ-butyrolactone were charged, and carbon monoxide was further introduced. When the autoclave is closed and the reactor is heated to 200°C, the initial pressure of the reaction system is 50 Kg/ca.
It was O. After completing the reaction for 3 hrs,
The autoclave was cooled, the product was taken out, and the product was quantified by gas chromatography, and the following results were obtained.

Conversion rate of methyl acetate 97% Yield of acetic acid /G I Yield of acetic anhydride 29.3% Example λ Instead of diphenyl(diethylamino)phosphine, phenyl-bis(diethylamino)phosphine (ph-p
(-Nbt2) 2) B. Using Ommol, the same reaction as in Example/ was carried out, and the following results were obtained.

Conversion rate of methyl acetate 79.7% Yield of acetic acid Yield of quenched acetic anhydride 8.3z Example 3 The reaction of Example/ was carried out in an acetic acid solvent. Conversion rate of methyl acetate 9.7% Anhydrous. A yield of acetic acid of 9.7z was obtained.

Example q K instead of diphenyl(diethylamino)phosphine, diphenyl(piperidino)phosphine (ph2-p-Q
) was used to carry out the same reaction as in Example 3, resulting in a conversion rate of methyl acetate of 779 g% and a yield of acetic anhydride of 770 g%.

EXAMPLE As a result of carrying out the reaction in Example D in the absence of a solvent, the conversion rate of methyl acetate was 77%, and the yield of acetic anhydride S, 9%.

Example: In a titanium autoclave with an internal volume of 200 mm, methyl acetate λ6A mmol, nickel metal powder, 3.31 nq
, at, Om, methyl iodide? 5 mmol, adduct of diphenyl(diethylamino)phosphine and methyl iodide *l) g, lI mmol, solvent acetic acid 2
0ml was charged, and carbon monoxide was further introduced. What is the initial pressure of the reaction system when the autoclave is closed and the reactor is heated to 200°C? ; It was OKg/crlG.

After completing the reaction, the autoclave was cooled, the product was taken out, and analyzed and quantified by gas chromatography. Conversion rate of methyl acetate: 4t, yield of 2.9% acetic anhydride: 36°. The results for each S were obtained.

*l) The adduct of diphenyl(diethylamino)phosphine and methyl iodide is a mixture with 16-. Note that ph represents a phenyl group, Me represents a methyl group, and gt represents an ethyl group.

Example 7 The same reaction as in Example 6 was carried out using diphenyl(piperidino)phosphine instead of the adduct of diphenyl(diethylamino)phosphine and methyl iodide. As a result, the conversion rate of methyl acetate was 2 g, 0% acetic anhydride. A yield of 2 g and a θ-based result were obtained.

Example In a Hastelloy C autoclave with an internal volume of 70 mm, methyl acetate/30 mmol, bis(acetylacetone)nickel 82 mm011 methyl iodide/9 mmol1+ n-
Ptyliminotrinoenylphosphorane (Ph5P = N
-n-Bu) 2 mmol and 10 rnl of γ-bunarolactone as a solvent were added, and carbon monoxide was further introduced. When the autoclave is closed and the reactor is heated to 200℃, the initial pressure of the reaction system is 0 K? /crl G. (7) After completing the reaction, cool the autoclave and take out the product,
As a result of analysis and quantitative analysis by gas chromatography, the conversion rate of methyl acetate was 67.0, the yield of acetic acid was 3θ, and the yield of acetic anhydride was 3.2Z.

Example? Dimethyl ether/30 mmol, bis(acetylacetone) nickel/, 2 mmol-1 methyl iodide/, 2 mmol, n~butyliminotrinoenylphosphorane (K'h3p = N-n) were placed in a Hastelloy C autoclave with an internal volume of 70 m1. -Bu) 3.
6 mmol, chromium hexacarbonyl 3. b m
mol-, 10 ml of dimethylimidazolidinone as a solvent was charged, and carbon monoxide was further introduced. When the autoclave was closed and the reactor was heated to 200°C, the initial pressure of the reaction system was TSQy, g/clrG. After continuing the reaction for 1 hour, the autoclave was cooled, the product was taken out, and analyzed and quantified by gas chromatography. The conversion rate of dimethyl ether was 3/7%, and the yield of methyl acetate was 6%. .2-/.

Results were obtained for the yield of acetic acid and the yield of acetic anhydride.

Sender: Mitsubishi Chemical Industries, Ltd.

Claims (1)

[Claims] (1) (a) Presence of at least seven compounds selected from the following general formula [1] 4 or [formula] and salts thereof, and (b) a catalyst containing nickel and C→diiodine. Below, a method for producing acetic anhydride characterized by reacting methyl acetate and/or dimethyl ether with carbon monoxide (in the above formula, R゛ to R° represent a hydrocarbon group which may have a substituent) However, R1 and R2, and R3 and R' may form a ring. )