JP2722490B2 - Production of urethane and carbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention uses a copper-based catalyst to react a primary amine, a hydroxyl-containing organic compound, carbon monoxide and molecular oxygen. , Urethane and carbonate.

Urethanes are compounds that are important as raw materials for carbamate pesticides per se, but recently can be easily converted to isocyanates for polyurethane production by heat treatment, so as an intermediate for isocyanate production without using toxic phosgene, An inexpensive manufacturing method is desired.

On the other hand, carbonic esters are compounds that are useful as an esterifying agent, a solvent, and the like in addition to being a starting material for producing polycarbonate.

(Prior Art) Conventionally, urethanes and carbonates have been produced by a phosgenation method of primary amines and alcohols. In recent years, various methods using no highly toxic phosgene have been proposed.

The method for producing urethane without using phosgene is roughly classified into a method using a nitro compound as a starting material and a method using a primary amine as a starting material.

A method using a nitro compound as a raw material is a reaction between a nitro compound such as nitrobenzene, an organic compound having a hydroxyl group such as an alcohol, and carbon monoxide in the presence of a platinum group compound such as palladium and rhodium or a catalyst mainly comprising selenium. To produce urethane reductively, for example, JP-A-55-51048, JP-A-52-153936, JP-B-45-24137,
It is described in JP-B-52-43822. In addition, JP-A-57-322
50 and JP-A-57-32251 describe a method for simultaneously producing urethane and a carbonate by reacting an aromatic nitro compound, an organic compound having a hydroxyl group and carbon monoxide in the presence of a catalyst mainly composed of palladium. ing.

On the other hand, the method using a primary amine as a raw material uses an oxygen or nitro compound as an oxidizing agent, and converts a primary amine such as aniline, an organic compound containing a hydroxyl group, and carbon monoxide to palladium, rhodium, ruthenium, or the like. Is a method of producing urethane oxidatively by reacting in the presence of a catalyst mainly comprising a platinum group compound of the type described in JP-A-55-124750, JP-A-55-120551, and JP-A-55-120551. Showa 55-120
551, and JP-A-59-172451.

(Problems to be Solved by the Invention) In the method using these nitro compounds or primary amines as raw materials, a catalyst mainly comprising a platinum group compound or selenium is used, but the main catalyst itself has low urethane synthesis activity. For,
Catalysts have been developed by combining iron chloride, iron oxychloride, vanadium oxychloride, lithium hydroxide, halides, Lewis acids and the like as cocatalysts, and pyridine, quinoline and the like as ligands. However, the use of these cocatalysts or ligands improves the urethane synthesis activity, but on the other hand, the catalyst becomes a multi-component system and becomes complicated, so that an expensive white metal compound can be efficiently recovered from the reaction product solution after the reaction. Re-use has the disadvantage that it requires complicated operations and large costs.

(Means for Solving the Problems) First, the present inventors have proposed a novel catalyst mainly composed of copper completely different from the conventional platinum group elements and selenium in a urethane production method using a primary amine as a raw material. A system was proposed (Japanese Patent Application No. 62-278328). That is, this is a method for producing urethane and carbonate by an carbonyl oxidation reaction of a primary amine with an organic compound having a hydroxyl group such as alcohol in the presence of a catalyst containing copper and halogen as active components.

In this method, aromatic urethanes such as phenylcarbamate were obtained in high yield from aromatic amines such as aniline as primary amines in high yield, but metaxylenediamine, 1,6-hexamethylenediamine and the like were obtained. In the production of the corresponding aliphatic urethane from the primary amine for producing the aliphatic isocyanate, the yield was lower than in the case of the aromatic urethane.

The present inventors have further studied the method of using the copper-based catalyst. As a result, by performing the above reaction in the presence of an oxygen-containing organic sulfur compound, the urethane yield can be obtained even in the production of an aliphatic urethane. Was found to be greatly improved, and the present invention was completed.

That is, the present invention provides an oxygen-containing organic sulfur compound in the presence of a catalyst system containing copper and a halogen as an active ingredient in an amount of 1 mol or more per 1 mol of an amino group of a primary amine to form a primary amine and a hydroxyl group. A method for producing urethane and carbonate, characterized by reacting a contained organic compound, carbon monoxide and molecular oxygen.

A major feature of the present invention resides in the use of a novel catalyst system mainly composed of copper, and in the presence of an organic hydroxy compound, high yield in the carbonylation reaction of a primary amine for producing an aliphatic isocyanate. It is to obtain the corresponding aliphatic urethane at a rate.

In the method of the present invention, since urethane and carbonate are obtained in the same catalyst system, it is presumed that two reactions represented by the following general formulas proceed simultaneously.

R ₁ (NH ₂ ) _n + n · CO + 1 / 2n · O ₂ + n · R ₂ OH → R ₁ (NHCOOR ₂ ) _n
+ N · H ₂ O (1) 2R ₂ OH + CO + 1/2 · O ₂ → CO (OR ₂ ) ₂ + H ₂ O (2) (where R ₁ and R ₂ are alkyl groups or aryl groups,
n is an integer of 1 or more. The copper catalyst used in the method of the present invention may be any one containing copper as a component, and may be a component forming metallic copper and a copper compound. The copper catalyst may be one supported on a carrier such as activated carbon, graphite, silica, and alumina. Copper compounds that can be used as a catalyst include, for example, copper iodide, copper bromide, copper chloride, copper oxide, copper sulfate, inorganic compounds such as copper nitrate, copper acetate, oxalic acid, and organic acid copper such as copper formate, Salts or complex compounds containing ammonia, amines, phosphines, carbon monoxide, chelating ligands and the like can be mentioned.

The amount of the copper catalyst to be used is 0.001 to 100 g atoms, preferably 0.01 to 10 g atoms, in terms of copper atoms per mole of the amino group of the primary amine. When the amount used is less than 0.001 g atom, the reaction rate is reduced, and when it exceeds 100 g atom, there is no adverse effect, but the above range is practical because it is not economical.

The halogen used in the present invention is selected from iodine, bromine and chlorine, and one or a mixture of two or more thereof may be used, with iodine being particularly preferred. The form of use of the halogen may be a halogen molecule itself or an organic or inorganic compound containing a halogen.
Examples of the halide include metal halides such as alkali metals and alkaline earth metals, onium compounds such as ammonium salts and phosphonium salts, oxoacids or salts of halogens, and organic halides such as methyl halide and ethyl halide. It is.

The amount of halogen used is 0.01 to 100 times, preferably 0.1 to 10 times, the amount of halogen atoms per 1 g of copper.

The catalyst of the present invention contains copper and halogen as active ingredients, but contains other elements such as tellurium, sulfur, antimony, bismuth, zinc, tin, vanadium, iron, cobalt, nickel, manganese, thallium, chromium, and molybdenum. , Tungsten and the like can be used as appropriate.

The oxygen-containing organic sulfur compound used in the method of the present invention includes:
Sulfones and sulfoxides. Specific examples include dimethyl sulfone, sulfolane, 2-methyl sulfolane, diphenyl sulfone, dimethyl sulfoxide, diethyl sulfoxide, tetramethyl sulfoxide, diphenyl sulfoxide, and the like, with sulfolane being particularly preferred.

The amount of the oxygen-containing organic sulfur compound used in the present invention is:
It is at least 1 mol, preferably 2 to 20 mol, per 1 mol of the amino group of the primary amine. If the amount is less than 1 mol, the effect of addition is small, and if it is more than 20 mol, the space-time yield decreases, so that the above range is practical.

The primary amine used as a starting material in the present invention is an aliphatic, aromatic, alicyclic or heterocyclic compound having at least one amino group in the molecule.

Aromatic or heterocyclic amines include, for example, aniline, 1,2
-Diaminobenzene, 1,4-diaminobenzene, isomer of chloroaniline, 3.4-dichloroaniline, 4-isopropylaniline, p-toluidine, chlorotoluidine, xylidine, alkoxyaniline, isomer of nitroaniline, 2,3-diamino Toluene, 2,4-diaminotoluene, 2,6-diaminotoluene, 2.5-diaminotoluene, 3,4-diaminotoluene, 3,5-diaminotoluene,
2-amino-4-nitrotoluene, 2-amino-3-nitrotoluene, 2-amino-5-nitrotoluene, aminophenols, diaminoxylene, anonitroxylenes, aminonaphthalenes, aminoanthracenes, chloroaminobenzoic acids, amino Benzenesulfonic acids,
4,4-diaminodiphenylmethane, 2,2-diaminodiphenylmethane, 2,4-diaminodiphenylmethane, tris- (4-aminophenyl) -methane, aminopyridines, aminoquinolines, aminopyrroles, aminofurans, aminothiophene Or 2-aminobenzothiazoles.

Alicyclic amines include, for example, aminocyclobutane, aminocyclopentane, cyclohexylamine, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4
-Diaminocyclohexane, bis- (aminocyclohexyl) -methanes.

Aliphatic amines include, for example, methylamine, ethylamine, 1-propylamine, 2-propylamine, 1-butylamine, 2-butylamine, isobutylamine, t
-Butylamine, 1-pentylamine, 1-hexylamine, 1-heptylamine, 1-octylamine, 1-
Decylamine, 1-dodecylamine, ethylenediamine, diaminopropanes, diaminobutanes, diaminopentanes, 1,6-hexamethylenediamine, and other diaminohexanes, diaminooctanes, diaminodecanes, benzylamine, bis- (aminomethyl ) -Cyclohexanes and bis- (aminomethyl) -benzenes such as meta-xylenediamine.

The hydroxyl group-containing organic compound used in the present invention includes alcohols and phenols having at least one OH group in the molecule.

Alcohols include, for example, methanol, ethanol, n
-Propanol, isopropanol, n-butanol,
t-butanol, n-pentanol, n-hexanol, cyclohexanol, benzyl alcohol, cycloethanol, ethylene glycol, diethylene glycol, propylene glycol, glycerol, and trimethylolpropane.

Phenols include, for example, phenol, naphthols,
Anthranol, phenanthrol and hydroxybenzofurans.

The amount of the organic compound containing a hydroxyl group to be used is 1 mol or more, preferably 5 mol or more, per 1 mol of the amino group of the primary amine. The upper limit of the amount is not particularly limited, but is practically 200 mol or less. If it exceeds 200 moles, the space-time yield is undesirably reduced.

The method of the present invention does not require a solvent, but a solvent inert to the reaction can be used in combination. Solvents, for example, pentane, hexane, heptane, aliphatic hydrocarbons such as octane, cyclohexane, alicyclic hydrocarbons such as tetralin,
Benzene, toluene, aromatic hydrocarbons such as xylene, acetonitrile, nitriles such as benzonitrile, tetrahydrofuran, ethers such as 1,4-dioxane, ketones such as acetone and methyl ethyl ketone, ethyl acetate,
Esters such as ethyl benzoate; and halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, chlorohexane, and trichlorotrifluoroethane.

Molecular oxygen used in the present invention is pure oxygen, air or other gas that does not inhibit the reaction thereof, for example, argon,
A solution diluted with an inert gas such as helium, nitrogen or carbon dioxide can also be used.

As the carbon monoxide, a mixed gas containing pure carbon monoxide and the above-mentioned inert gas, and in some cases, hydrogen, hydrocarbon gas and the like can be used.

The reaction temperature of the present invention is 50-300 ° C., preferably 1
00-250 ° C. At a reaction temperature lower than 50 ° C., the reaction rate decreases, and at a temperature higher than 300 ° C., side reactions increase.

The reaction pressure is 1 to 500 kg / cm ² G, and practically 20 to 3
A range of 00 kg / cm ² G is preferred. The reaction time varies depending on the catalyst system, the amount of the catalyst, the reaction conditions and the like, but is usually several minutes to several hours.

The present invention can be suitably carried out by a batch system or a continuous system.

(Effect of the Invention) The present invention is a method for producing urethane and carbonate from a primary amine, an organic compound containing a hydroxyl group, carbon monoxide and molecular oxygen, and handles highly toxic phosgene as in the current method. The advantage is that there is no occurrence of hydrochloric acid and there is no by-product of hydrochloric acid.

Conventional catalyst systems are mainly based on expensive platinum group elements such as palladium, rhodium and ruthenium or toxic selenium.To promote the activity and stability of the catalyst, a cocatalyst containing a foreign metal element, a ligand, In addition, a large amount of additives and the like must be used in combination, and the catalyst composition tends to be multi-component and complicated.

On the other hand, the method of the present invention has the advantage that a high activity can be obtained with an inexpensive copper-based catalyst system, and the catalyst can be easily recovered and reused because the catalyst is a simple system and does not contain any dissimilar metals. There is.

As described above, the method of the present invention can efficiently produce the corresponding urethane and carbonate by the carbonylation reaction of aromatic and aliphatic primary amines in the presence of a hydroxyl group-containing organic compound, This is an industrially advantageous method.

(Example) Next, the method of the present invention will be described more specifically with reference to examples.

Example 1 1 g (7.34 mmol) of metaxylene diamine (hereinafter referred to as MXDA), 8 g (250 mmol) of methanol, and 6 g of sulfolane were placed in a Hastelloy autoclave having an inner volume of 100 ml.
(49.9 mmol) and 0.48 g (2.52 mmol) of copper iodide
And sealed. The partial pressure of carbon monoxide is 75 kg / cm ²
G, each gas was injected so that the partial pressure of air was 35 kg / cm ² G, and the reaction was carried out at a reaction temperature of 165 ° C. for 2 hours.

After the reaction, the residual gas was purged while cooling the autoclave, and the reaction product was analyzed by a high performance liquid chromatograph and a gas chromatograph by an internal standard method.

As a result, the yield of diurethane [1.3-phenylenebis (methylene) biscarbamate] based on MXDA was 9%.
At the same time, 1.86 mmol of dimethyl carbonate was produced.

Examples 2 to 3 The reaction was carried out in the same manner as in Example 1 except that sulfolane / amino group (molar ratio) was changed to 4.54 to 9.65.

First diurethane yield and dimethyl carbonate yield based on MXDA
It is shown in the table.

Example 4 1 g (7.34 mmol) of MXDA, 8 g (250 mmol) of methanol, 17 g of dimethyl sulfoxide (2 g) instead of sulfolane
18 mmol) and 0.48 g (2.52 mmol) of copper iodide were charged and reacted in the same manner as in Example 1. As a result MX
The diurethane yield based on DA was 85.5%, and the yield of dimethyl carbonate was 5.81 mmol.

Example 5 8 g (174 mmol) of ethanol as an alcohol raw material
The reaction was carried out under the same conditions as in Example 2 except that was used. As a result, the yield of diurethane [diethyl 1,3-phenylenebis (methylene) biscarbamate] based on MXDA was 8%.
9.0%, and the yield of diethyl carbonate was 0.59 mmol.

Example 6 1 g of 1,6-hexamethylenediamine as an amine raw material
(8.61 mmol), methanol 8 g (250 mmol), sulfolane 6 g (49.9 mmol) and copper iodide 0.48 g (2.52 mmol)
Mmol) and the partial pressure of carbon monoxide is 75 kg / c.
Each gas was injected under pressure such that m ² G and the partial pressure of air became 35 kg / cm ² G, and the reaction was carried out at a temperature of 175 ° C. for 1 hour. As a result,
The yield of diurethane (dimethyl 1,6-hexamethylenecarbamate) based on 6-hexamethylenediamine was 82.3%, and at the same time, 3.21 mmol of dimethyl carbonate was produced.

Example 7 As an amine raw material, 1 g (10.7 mmol) of aniline, 8 g (173.6 mmol) of ethanol, 8 g (66.6 mmol) of sulfolane, and 0.48 g (2.52 mmol) of copper iodide were charged, and the partial pressure of carbon monoxide was increased. 75 kg / cm ² G, each gas so that the partial pressure of the air is 35 Kg / cm ² G was pressed at a temperature 158 ° C.
For 2 hours. As a result, the yield of urethane (ethyl N-phenylcarbamate) based on aniline was 95.8%.
And the yield of diethyl carbonate was 0.52 mmol.

Comparative Example 1 MXDA 1 g (7.34 mmol) and methanol 8 g as raw materials
(250 mmol), and copper iodide 0.48 g (2.52 mmol)
And reacted in the same manner as in Example 1 except that sulfolane was not used. As a result, the diurethane yield based on MXDA was 60.9%, and at the same time, dimethyl carbonate was 2.10%.
47 mmol were produced.

Comparative Example 2 A reaction was conducted in the same manner as in Example 4 except that 17 g (151 mmol) of chlorobenzene was used instead of sulfolane. As a result, the diurethane yield based on MXDA was 60.3%, and the yield of dimethyl carbonate was 1.43 mmol.

Comparative Example 3 A reaction was conducted in the same manner as in Example 1 except that sulfolane / amino group (molar ratio) was set to 0.85. As a result, the diurethane yield based on MXDA was 64.8%, and at the same time, 4.76 mmol of dimethyl carbonate was produced.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C07B 61/00 300 C07B 61/00 300

Claims (1)

(57) [Claims] An oxygen-containing organic sulfur compound is present in the presence of a catalyst system containing copper and a halogen as an active ingredient in an amount of 1 mol or more per 1 mol of an amino group of a primary amine.
A method for producing urethane and a carbonate, comprising reacting a hydroxyl group-containing organic compound, carbon monoxide and molecular oxygen.