JPS60193959A - Production of aromatic urethane - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as a raw material of carbamate pesticides, and a raw material of aromatic isocyanate, economically, by reacting an aromatic nitro compound with a specific carbon monoxide source and a specific hydroxyl-containing organic compound in the presence of a platinum-group metal catalyst. CONSTITUTION:The objective compound can be produced by reacting (A) an aromatic nitro compound with (B) carbon monoxide and a hydroxyl-containing organic compound produced by using a converter gas having a hydrogen content of <=1vol%, preferably <=0.1vol% as a carbon dioxide gas source, in liquid phase, in the presence of a platinum-group metal catalyst, at 100-250 deg.C under a carbon monoxide partial pressure of 10-1,000kg/cm<2>, preferably at 140-190 and 30- 300kg/cm<2>, for 0.5-10hr. The catalyst is e.g. palladium chloride, palladium acetate, etc. A Lewis acid or a nitrogen-containing heteroaromatic compound is preferably used as a cocatalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for economically producing aromatic urethane using converter gas as inexpensive carbon monoxide.

[Technical background of the invention and its problems] Aromatic urethane is also used as a raw material for carbamate pesticides, but aromatic isocyanate (a raw material for polyurethane used in soft and hard foams, paints, fibers, etc.) It is a chemical substance useful as a raw material for

Conventionally, aromatic isocyanates have been produced by reacting aromatic amines obtained by hydrogen reduction of aromatic nitro compounds with phosgene. However, this method is complicated and requires the use of toxic phosgene.
There were problems such as a large amount of hydrogen chloride produced as a by-product. Therefore, in recent years, inexpensive manufacturing methods that do not use phosgene have been proposed.

These methods are roughly divided into two types: 1) direct method and 2) urethane-mediated method. The first method is to directly obtain an aromatic isocyanate from an aromatic nitro compound in the presence of a palladium-based catalyst in an inert solvent. This method has drawbacks such as harsh reaction conditions, low catalytic activity and poor yield, and simultaneous occurrence of side reactions. The second target of the present invention
The method involves reacting an aromatic nitro compound with carbon monoxide in a compound having a hydrogen group in the presence of a platinum group metal catalyst or a selenium catalyst to obtain an aromatic urethane, and then thermally decomposing the urethane. This is a method for obtaining aromatic isocyanates. Although this method shows quite excellent results with a urethane yield of 80 to 90% even when dinitro compounds are used as raw materials, a cheaper method is desired for industrialization.

Against this background, JP-A-55-7227 discloses a method for producing urethane by reacting an aromatic nitro compound with a compound containing carbon monoxide and a hydrogen group in the presence of a palladium catalyst. It is proposed that hydrogen be present in the system.

Although the presence of hydrogen increases the urethane yield, this process uses GO and H2 of relatively high purity, and the purification and separation of these gases is costly.

Furthermore, JP-A-57-185253 proposes a method for producing aromatic urethane in which an aromatic amino compound or an aromatic nitro compound is reacted with an organic hydroxyl compound, hydrogen, and carbon monoxide in the presence of a similar catalyst. There is. This reaction uses aromatic amines and aromatic nitro compounds, which are more expensive than aromatic nitro compounds, as raw materials, and uses hydrogen and synthesis gas as a carbon monoxide source.

On the other hand, converter gas discharged from an oxygen steelmaking furnace at a steelworks contains nitrogen and carbon dioxide, but contains extremely little sulfur and dust, so it can be considered an excellent source of carbon monoxide. In particular, in the case of a bottom-blown furnace, the -carbon oxide concentration reaches 80% or more.

[Object of the invention] In view of the above, the present invention provides a more economical aromatic urethane by using converter gas with a hydrogen content of 1% or less as a carbon dioxide gas source when producing aromatic urethane. The purpose of the present invention is to provide a method for producing group urethanes.

[Summary of the Invention] The gist of the present invention to achieve the above objects is to react an aromatic nitro compound, an organic compound containing a carbon oxide and a hydroxyl group in a liquid phase in the presence of a platinum group metal catalyst to produce an aromatic A method for producing an aromatic urethane, characterized in that a converter gas having a hydrogen content of 1% or less is used as a carbon oxide source. That is, the present invention effectively uses converter gas, which has been used only as a fuel, as a carbon monoxide source in the production of aromatic urethane, thereby producing inexpensive aromatic urethane (and by extension, inexpensive aromatic urethane, which is a raw material for polyurethane). isocyanates) with a yield comparable to that of pure carbon oxide sources.

[Specific examples of the invention] The present invention will be further explained in detail.

The aromatic nitro compound used as a main raw material in the production method of the present invention may be either a mononitro compound or a polynitro compound. For example, these include nitrobenzenes, dinitrobenzenes, dinitrotoluenes, nitronaphthalenes, nitroanthracenes, nitrobiphenyls, bis-trophenyl) alkanes, bis-trophenyl) ethers, nitrodiphenoxyalkanes. and heteroaromatic compounds such as 5-nitropyrindine. In the above compounds, nitro/nitroalkyl, alkyl, alkenyl.

Alkoxy, halogen, carboxy, alkyl.

Alternatively, it may be substituted with additional substituents.

Specific compounds include nitrobenzene, 0-, m-
and p-nitrotoluene, 0-nitro-p-xylene, 1-nitronaphthalene, i- and p-dinitrobenzene, 2,4- and 2゜6-sinitrotoluene, dinitromesitylene, 4゜4'-dinitrobiphenyl, 2 ．．
4'-dinitrodophenyl, 4,4'-dinitrodibenzyl, bis(4-nitrophenyl)methane, bis(4
-nitrophenyl) ether, bis(4-nitrophenoxy)nitane, α, α′-dinitro p-xylene,
o-, m- and p-chloronitrobenzene, 1-chloro-2,4-dinitrobenzene, 1-bromo-4-nitrobenzene, 1-fluoro-2,4-dinitrobenzene, o-, m- and p -nitroanthol, 2,
4-Dinitrophenetol 1m-nitrobenzaldehyde, ethyl-p-nitrobenzoate, 3.3'-dimethyl-4゜4'-dinitrobia-9-
Examples include h-decaphthalene. Furthermore, isomers or mixtures of these aromatic nitro compounds can also be used.
Congeners can also be used.

The hydrous acid group compound used in the production method of the present invention includes first,
Included are m alcohols or polyhydric alcohols containing secondary or tertiary hydroxyl groups, and monohydric phenols or polyhydric phenols. If alcohol is represented by R(OH)n, R is a straight-chain or branched alkyl, cycloalkyl, or alkylene.

It is cycloalkylene or aralkyl, and n is 1 or 2 or more. They may also contain substituents containing oxygen, nitrogen or halogen atoms, such as carbonyls, carboxylic acid ester groups, amines, amides or halogens.

Specific examples of R(OH)n include methyl alcohol, ethyl alcohol, n- and 1sO-propyl alcohol, n-, 1so- and t-propyl alcohol, linear or branched amyl alcohol, hexyl alcohol, cyclo- xylcol.

Single alcohols such as lauryl alcohol, cetyl alcohol, benzyl alcohol, tribenzyl alcohol and methoxyberzyl alcohol, ethylene glycol, diethylene glycol.

Examples include dihydric alcohols such as propylene glycol and dipropylene glycol, trihydric alcohols such as glycerol and hexanetriol, and even more polyfunctional polyols. Among these, particularly preferred alcohols are methanol and ethanol. The phenols used are phenol, chlorophenol, cresol, ethylphenol or linear or branched propylphenol, butyl and higher alkylphenols, catechol, resorcinol.

4.4'-dihydroxydiphenylmethane, 2゜2'-
Examples include improvylidene diphenol, anthranol, phenanthrol, pyrogallol, phloroglucinol, and the like. Of these, phenol is particularly advantageous.

The main components of the platinum group metal catalyst used in the method of the present invention are palladium, rhodium, platinum, ruthenium, and osmium alone or in combinations of one or more of these. Chemical forms of these platinum group metal compounds include halides, oxides, sulfates, nitrates, acetylacetonate salts, carbonyl compounds, and complexes with organic phosphorus compounds such as triphenylphosphine. Among these, palladium and rhodium alone or as a compound are particularly preferred.

Examples of catalysts suitable for use are palladium chloride, palladium acetate, palladium oxide, palladium nitrate, rhodium trichloride, rhodium sesquioxide, platinum sulfate, platinum nitrate,
These include platinum acetate, platinum dichloride, ruthenium trichloride, ruthenium dioxide, and osmium tetrachloride. Also included in the above examples are platinum group metal compounds in the form of complex salts, such as soluble compounds such as potassium and sodium tetrachlorparadate, potassium tetrachlorplatinate.

These main catalyst components may be used in the reaction as they are, with or without the use of a physical support. Supports include alumina, silica, activated carbon, barium nitrate,
Calcium carbonate, asbestos, diatomaceous earth, ion exchange resin, magnesium silicate, aluminum silicate, molecules, sieves, etc. are used.

In the method of the present invention, Lewis acids are widely used as cocatalysts. As these Lewis acids, under the reaction conditions,
Compounds obtained from elements of groups 11rA to VII of the periodic table and subgroups IB to VB which undergo redox reactions are suitable. For example, tin, titanium, zirconium, vanadium, niobium.

Halides, oxyhalides, sulfates, phosphates, nitrates of germanium, aluminum, iron, nickel, molybdenum, tungsten, manganese, cobalt, etc.
oxide, acetylacetonate, and/or oxyacetylacetonate. When using oxides or hydroxides, it is preferred to add certain activated halides, especially activated chlorides.

Examples of suitable Lewis acids include the following compounds. Copper(I) chloride, copper<II) chloride.

Copper acetate (■), thallium (I [I) chloride, tin ([) chloride, tin (IV) chloride, bismuth (III) chloride,
Vanadium (I[[) chloride, chromium (I[[) chloride, aluminum (I[[) chloride, molybdenum (IV)]
Chloride, Tungsten (Vl Chloride, Tungsten (V
I) Chloride, manganese (It) chloride.

Iron (IF) chloride, iron (In>chloride, iron (I[[) oxychloride, cobalt (II>chloride), copper (I[) oxide, copper (I[) hydroxide, thallium (I) )hydroxide,
Tin (IF) oxide, tin (II> hydroxide, vanadium (
V) oxide, molybdenum (VI) oxide.

Tungsten (VI) oxide, manganese (IV> oxide, iron (1) hydroxide, iron (■) @ oxide, among these,
Particularly preferred Lewis acids include iron(II) chloride, iron(Ill) chloride and oxychloride.

In the catalyst system of the present invention, it is preferred to use a nitrogen-containing heteroaromatic compound together with a Lewis acid as a cocatalyst. Here, the nitrogen-containing heteroaromatic compound refers to a nitrogen-containing heteroaromatic cyclic compound, and even if they are in an unsubstituted form,
Alternatively, a suitable substituent such as a halogen atom, an alkyl group, an aryl group, an alkenyl group, a cyano group, an aldehyde group, an alkoxy group, a phenoxy group, a carbalcoquine group.

It may contain a substituent such as a carbamyl group or a carboallyloxy group. In addition, single salts of nitrogen-containing heteroaromatic compounds such as nitrates, hydrohalides, sulfates, acetates, etc. are also used. Furthermore, quaternary salts of nitrogen-containing heteroaromatic compounds and oxides of nitrogen-containing heteroaromatic compounds can also be used.

Specific examples include 1-methylpyrrole, 1-phenylpyrrole, 1-methylimidazole, 1-methylindo
-ol, 1-phenylindole, 1-methylcarbazole, pyridine, 2-chloropyridine, 2-bromopyridine, 2-fluorogolidine, 4-phenylpyridine, 2
-methylpyridine, 2-methyl-5-ethylpyridine,
2-6-dimethylpyridine, 2-4-6-1-limethylpyridine, 2-vinylpyridine, 2-styrylpyridine, 3-chloropyridine, 2-6-dichloropyridine, 2
-Chloro-4-methylpyridine, 2-methoxypyridine, 4-4 dimethylamino pyridine.

α-picolinate phenyl ester, γ-picolinate methyl ester, 2-6-dicyatsubiridine, α-picolinaldehyde, α-picolinamide, 5゜6.7.8-tetrahydroquinoline, 2-2=-dipyridyl, quinoline,
Isoquinoline, 2-chloroquinoline, acridinephenanthridine, benzoquinoline, benzoisoquinoline, naphthyridine pyrazine, 4,6-dimethylvirazine, 2.
6-dimethylvirazine, pyridazine, pyrimidine, quinoxaline, 2-3-dimethylquinoxaline, quinazoline, phthalazine, phenazine, cinnoline.

Examples include pteridine.

These nitrogen-containing heteroaromatic compounds can be added to the X reactor separately from other catalyst components, or can be treated in advance with other components of the catalyst system to form suitable compounds such as complexes and adducts. be able to.

It is well known that nitrogen-containing heteroaromatic compounds in particular form complexes with platinum group compounds or Lewis acids.

For example, pyridine, quinoline, isoquinoline, etc.
Examples include complexes with halides, cyanides, and incyanides of palladium, rhodium, platinum, etc., and specifically palladium(II) chloride-pyridine complexes represented by pd(glysine)2C12. Also pyridine, quinoline.

Isoquinoline, γ-picoline, etc., and iron, tin, etc.

complexes of, for example, Fe(pyridine)2CZ2°Sn
Iron(I) chloride represented by (pyridine)2CZ4-
Examples include pyridine complexes and tin(IV) chloride-pyridine complexes.

In the method of the present invention, the molar ratio of the platinum group element in the catalyst consisting of the platinum group metal to the aromatic nitro compound can be varied over a wide range;
That is, it can vary from 1:5 to 1:2000, but the preferred range is from 1:10 to 1:100.
It is 0. Here, mole has the same meaning as Durham equivalent or formula for platinum group metals or their compounds.

The Lewis acid used as a promoter has a molar ratio of 0.1:1 to 1000 to the platinum group metal or its compound.
:1 Preferably used in a range of 1:1 to 100:1. The amount of the nitrogen-containing heteroaromatic compound to be added is from 0.1:1 to 1000:1 in molar ratio to the platinum group metal or its compound as the main catalyst.
1, preferably in the range of 1:1 to 100:1.

In the method of the present invention, it is important to maintain the hydrogen content in the feedstock converter gas below a predetermined concentration, and as a result, the production efficiency of the target aromatic urethane is significantly increased, and the pure-carbon oxide raw material at the same partial pressure is - reaches the same level as when using -. This permissible hydrogen content is 1,0 vol for converter gas.
1%, preferably 0.5 voj! %More preferably,
The VO deficiency is 0.1% or less, which corresponds to approximately 10%, preferably 5%, and more preferably 1% or less, expressed as a molar ratio to the nitro group of the raw material nitro compound. Converter gas composition varies depending on operating standards, but is usually - 55-75% carbon oxide, 10-18% carbon dioxide, 10% nitrogen.
~20%, hydrogen 15%, oxygen 0.1~0.6% by volume.

There are no particular restrictions on the method of adjusting the hydrogen content to 1% or less, and physical methods such as selective adsorption or storage of hydrogen, combustion with oxygen, catalytic dehydrogenation using a palladium catalyst, etc. Chemical methods can also be used.

Alternatively, it may be obtained by mixing with a gas having a lower hydrogen content.

Although the method of the present invention can be carried out without the presence of a solvent, it may also be carried out diluted with a solvent inert to the reaction. A suitable solvent is n-hexane.

Aliphatic or aromatic hydrocarbons such as benzene, toluene, xylene, nitriles such as acetonitrile, benzonitrile, 1.1.2-1-dichlor. 1.2.2
Examples include aliphatic or aromatic halogenated hydrocarbons or ketones such as trifluoroethane, monochlorobenzene, dichlorobenzene, and trichlorobenzene, esters tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, and the like. The reaction is preferably carried out using at least an equimolar amount of carbon monoxide and a hydrous acid group compound relative to the nitro group of the aromatic nitro compound as the main raw material. There are no particular restrictions on the charging method and order of addition of raw materials and catalysts, and they can be changed within the limitations of the equipment used. The reaction may be carried out batchwise, semi-continuously or continuously. The reaction temperature is generally maintained in the range of 100° to 250°C, with a range of 140° to 190°C being particularly preferred. The reaction pressure is 10 to 1000 kg/cm2-G, more preferably 30 to 3.00 ko/cm2-G as a partial pressure of carbon monoxide.
is within the range of The reaction time depends on the nature of the aromatic nitro compound used and the reaction temperature.

Generally, 0.5 to 6 hours is sufficient, although it varies depending on various factors such as reaction pressure, type of catalyst, and m1 reactor. After the reaction is finished, the reaction mixture is cooled to room temperature,
Depressurize. The reaction product is then treated by conventional methods, including filtration, distillative extraction, or other suitable separation methods, to separate the desired aromatic urethane from unreacted products, by-products, solvents, catalysts, and the like. The separated and recovered catalyst can be recycled as it is, or after being purified by an appropriate method such as a solvent washing method and having its composition adjusted.

[Examples and Comparative Examples] The effects of the present invention will be described below using Examples and Comparative Examples. The converter gases with different hydrogen contents used in the reaction were
It was adjusted by using a palladium molybdenum catalyst synthesized with reference to the method described in No. 0-15496 and by changing the coexisting oxygen gas supply. In addition, a shaking autoclave made of stainless steel was used for all reactions. Also,
Conversion rates and yields are calculated from the results of gas chromatography and high performance liquid chromatography analysis and are based on molar amounts.

(Examples 1 to 4) Nitrobenzene 0.82011, commercially available 5 wt% palladium activated carbon 0.130111, ferric chloride 0.28
0G, pyridine 0.29017, and dehydrated ethanol 1oII11 were charged into an autoclave with an internal volume of 3011%, and the gas composition inside was 68% carbon monoxide, 1% carbon dioxide.
5%, nitrogen 14%, hydrogen 2.5%, oxygen 0.5% carbon monoxide source pressure 701o/am.
It was press-fitted until it reached 2-G. Immerse the autoclave in a pre-humidified oil bath and raise the temperature while shaking and stirring.
The temperature was kept at 5 to 160°C and the reaction was carried out for 2 hours. After the reaction was completed, it was cooled to room temperature, evacuated, and insoluble matter was filtered out.
1 of dehydrated ethanol. Combine the filtrate and washing liquid,
The products in the liquid were analyzed. In Examples 2 to 4, the hydrogen content of the converter gas was 1.4vo [%, 0.8v.

%, which was changed to 0.4 VO 1%. Table 1 shows the nitrobenzene reaction rate (%) and the yield of ethyl N-phenylcarbamate (aromatic urethane).

(Comparative Example 1) Carbon monoxide 70%, carbon dioxide 15.5%, nitrogen 14%
Except that a gas with a composition consisting of 0.5% oxygen was used.
The reaction was carried out in the same manner as in the example. The results are shown in Table 1.

(Comparative Example 2) The reaction was carried out in the same manner as in the example except that pure carbon monoxide was used. The results are shown in Table 1.

Table 1 [Effects of the Invention] As described above, according to the present invention, since the converter gas adjusted to have a hydrogen content of 11 vo depletion% or less is used as the carbon monoxide source, the carbon source of the conventional method is used. It is possible to obtain a nitrobenzene reaction rate and urethane yield comparable to that of the method, and it is also significantly more economical.

Procedural amendment (spontaneous) June 10, 1985 Patent Application No. 49589 2 Title of invention Process for producing aromatic urethane 3 Relationship with the person making the amendment Patent applicant 4 Agent 〒101 8゛ff1iiEE(') @ The full text of the specification will be corrected as shown in the attached sheet.

Description 1, Name of the invention Process for producing aromatic urethane 2, Claims (1) An aromatic nitro compound, an organic compound containing carbon oxide and a hydroxyl group, in a liquid phase, in the presence of a platinum group metal catalyst. In a method for producing aromatic urethane by reacting with
- A method for producing aromatic urethane, characterized in that a converter gas having a hydrogen content of 1 vol % or less is used as a carbon oxide source.

3. Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a method for economically producing aromatic urethane using converter gas as inexpensive carbon monoxide.

[Technical background of the invention and its problems]

Aromatic urethane is also used as a raw material for carbamate pesticides, but it is also a useful chemical substance as a raw material for aromatic incyanate (a raw material for polyurethane used in soft and hard foams, paints, fibers, etc.). be.

Conventionally, aromatic incyanates have been produced by reacting aromatic amines obtained by hydrogen reduction of aromatic nitro compounds with phosgene. However, this method is not only complicated, but also uses toxic phosgene.
There were problems such as a large amount of hydrogen chloride being produced as a by-product.Therefore, in recent years, inexpensive production methods that do not use phosgene have been proposed.These methods are 1) direct method, 2) urethane-mediated method. The first method is to directly obtain an aromatic incyanate from an aromatic nitro compound in the presence of a palladium catalyst in an inert solvent. This method requires harsh reaction conditions, low catalyst activity and poor yield.
It has disadvantages such as side reactions. The second method covered by the present invention is to react an aromatic nitro compound with carbon monoxide in a compound having a hydroxyl group in the presence of a platinum group metal catalyst or a selenium catalyst to obtain an aromatic urethane, and then This is a method of obtaining aromatic isocyanate by thermally decomposing the urethane. This method also shows excellent results with a urethane yield of 80 to 90% even when dinitro compounds are used as raw materials, but a more economical method is desired for industrialization. , JP-A-55-7227 discloses a method for producing urethane by reacting an aromatic nitro compound with a compound containing carbon monoxide and a hydroxyl group in the presence of a palladium catalyst, in which hydrogen is present in the reaction system. O is proposing that
Although the presence of hydrogen increases the urethane yield, this method uses relatively high-purity CO and H2, which increases the cost of gas purification and separation. JP-A-57-185253 proposes a method for producing aromatic urethane in which an aromatic amine compound and an aromatic nitro compound are reacted with an organic hydroxyl compound, hydrogen and carbon monoxide in the presence of a similar catalyst. This reaction uses aromatic amines and aromatic nitro compounds, which are more expensive than aromatic nitro compounds, as raw materials.
Synthesis gas is used as a source of hydrogen and carbon monoxide.On the other hand, the converter gas discharged from oxygen steelmaking furnaces at ironworks contains nitrogen and carbon dioxide, but only sulfur.

Since it produces very little dust, it can be considered an excellent source of carbon monoxide. In particular, in the case of a bottom blowing furnace, the concentration of -carbon oxide reaches 80 or more.

[Purpose of the invention]

In view of the above, the present invention provides the following advantages by using converter gas with a hydrogen content of 1 tre or less as a carbon monoxide (gas) source when producing aromatic urethane.
[Summary of the Invention] The gist of the present invention for achieving the above object is to provide a more economical method for producing aromatic urethane. A method for producing aromatic urethane by reacting an organic compound in a liquid phase in the presence of a platinum group metal catalyst, characterized in that a converter gas with a hydrogen content of 1% or less is used as a carbon oxide source. In other words, the present invention is directed to a method for producing aromatic urethane, by effectively using converter gas, which has no other use, as a carbon monoxide source in the production of aromatic urethane. The aim is to produce an inexpensive aromatic urethane (and by extension, an inexpensive aromatic incyanate, which is a raw material for polyurethane) at a yield comparable to that of a pure carbon oxide source.

[Specific examples of the invention] The present invention will be further explained in detail.

The aromatic nitro compound used as the main raw material in the production method of the present invention may be either a mononitro compound or a polynitro compound. Heteroaromatic compounds such as nitroanthracenes, nitrobiphenyls, bis(dicrophenyl)alka/s, bis(trophenyl)ethyls, nitrosifethoxyalkanes, or 5-nitropyridine, etc. be.

In the above compounds, 1 such as nitro, nitroalkyl, alkyl, alkenyl, alkoxy, halogen, carboxy, alkyl, cyanogen, incyanate, etc.
It may be substituted with n or more substituents.

Specific compounds include nitrobenzene, m- and p-nitrotoluene, 0-nitro-p-xylene,
1-nitronaphthalene, m- and p-dinitrobenzene, 2,4- and 2,6-sinitrotoluene, dinitromesiti v:y, 4.4”) nitrobiphenyl>2.4
'-Dinitrobiphenyl, 4,4'-dinitrobenzea, bis(4-nitrophenyl)methane, bis(4-nitrophenyl)ether, bis(4-nitrophenoxy)
Eta: /, α, α′-dinitro p-xylene, 0 +
m- and p-chloronitrobenzene, 1-chloro-2
, 4-dinitrobenzene, l-promo 4-nitrobenzene, 1-fluoro-2,4-dinitrobenzea, o
-, m- and p-nitroanthol, 2,4-dinitrobenzal, m-nitrobenzaldehyde, ethyl-p-nitrobenzoate, 3,3'-dimethyl-4
, 4'-dinitrobiphenyl, and 1,5-dinitronaphthalene. Furthermore, isomers or mixtures of these aromatic nitro compounds can also be used, and homologs can also be used.

The hydrous acid group compound used in the production method of the present invention includes the first,
A monohydric alcohol or polyhydric alcohol containing a secondary or tertiary hydroxyl group and an alcohol containing m phenols or polyhydric phenols are represented by R(OH)n, where R is a straight chain or Branched alkyl, cycloalkyl.

alkylene, cycloalkylene or aralkyl; n is 1 or 2 or more; They may also include substituents containing oxygen, nitrogen or halogen atoms, such as carbonyl, carboxylic ester groups, amines, amides or halogens.

Specific examples of R(OH)n include methyl alcohol, ethyl alcohol v n-oyo0: iso-propyl alcohol + n + 180- and tert-butyl alcohol, linear or branched amyl alcohol, hexyl alcohol, cyclohexyl alcohol. Monoalcohols such as lauryl alcohol, cetyl alcohol, benzyl alcohol, chlorobenzyl alcohol and methoxyberzyl alcohol, dihydric alcohols such as ethylene glycol, diethylene glycol, phlopylene gelicol, dipropylene glycol, glycerylol, hexanetriol. trihydric alcohols, such as
Further examples include polyfunctional polyols, among which particularly preferred alcohols are methanol and ethanol. Phenols which may be used include phenol, chlorophenol, cresol, ethylphenol or linear or branched propylphenol, butyl and higher alkylphenols, catechol, resorcinol, 4,4'-dihydroxydiphenylmethane.

2.2'-Impropylidene diphenol, anthranol, phenanthrol, hyrogallol.

Of these, phenol is particularly advantageous, including phloroglucinol.

The main components of the platinum group metal catalyst used in the method of the present invention are palladium, rhodium, and platinum.

Ruthenium or osmium is a single substance or a compound thereof, and is a mixture of one or more of them. Among the chemical forms of these platinum group metal compounds are halides, oxides, sulfates, and nitrates.

Examples include acetylacetonate salts, carbonyl compounds, and complexes with organic phosphorus compounds such as triphenylphosphine.Among these, palladium and rhodium alone or as compounds are particularly preferred. Specific examples of catalysts suitable for use are palladium chloride, palladium acetate, palladium oxide, palladium nitrate, rhodium trichloride,
Rhodium sesquioxide, platinum sulfate, platinum nitrate.

Platinum group metal compounds in the form of complex salts such as platinum acetate, platinum dichloride, ruthenium trichloride, ruthenium dioxide, osmium tetrachloride, such as potassium and sodium tetrachloride. Soluble compounds such as valadate, potassium tetrachloroplatinate are also included in the above examples.
These main catalyst components may be used in the reaction as they are with or without a physical support. Supports include alumina, silica, activated carbon, barium sulfate, and calcium carbonate.

Asbestos, diatomaceous earth, ion exchange resin, magnesium silicate, aluminum silicate, molecular sieves, etc. are used.

In the method of the present invention, Lewis acids are widely used as cocatalysts. As these Lewis acids, under the reaction conditions,
Compounds obtained from elements of groups IIA to V and subgroups IB to VB of the periodic table which undergo redox reactions are suitable.

For example, tin, titanium, zirconium, vanadium, nioff, kermanium, aluminum.

halides, oxyhalides, sulfates, phosphates, nitrates, oxides, acetylacetonates and/or oxyacetylacetonates of iron, nickel, molybdenum, tungsten, manganese, cobalt, etc. Oxides Alternatively, when a hydroxide is used, it is preferable to add some kind of activated halide, especially activated chloride.

Examples of suitable Lewis acids include the following compounds:
0 copper (1) chloride, copper 01) chloride, copper acetate (■),
Thallium(2) chloride, tin(II) chloride, tin(II) chloride, bismuth(t) chloride, vanadium(II) chloride.

Chromium chloride, aluminum chloride 1%
! J Futen (Incorporated) chloride, tungsten chloride, tungsten chloride, manganese (II) chloride, iron (U) chloride, iron (2) chloride, iron (2) oxychloride, Cobalt (n) chloride, copper ω) oxide, copper (I)
I) hydroxide, thallium CI) hydroxide, tin(II) oxide, tin(If) hydroxide.

Vanadium oxide, molybdenum oxide, tungsten oxide, manganese oxide, iron
2) Hydroxide, Iron(2) Oxide Among these, particularly preferred Lewis acids include iron(II) chloride, iron-chloride, and oxychloride.

In the catalyst system of the present invention, it is preferred to use a nitrogen-containing heteroaromatic compound together with a Lewis acid as a cocatalyst. Here, the nitrogen-containing heteroaromatic compound refers to a nitrogen-containing heteroaromatic cyclic compound, and even if they are in unsubstituted form,
Alternatively, a suitable substituent such as a halogen atom, an alkyl group, an aryl group, an alkenyl group, or a cyano group.

Aldehyde group, alkoxy group, phenoxy group.

It may contain a substituent such as a carbalkoxy group, a carbamyl group, or a carboallyloxy group.

In addition, single salts of nitrogen-containing heteroaromatic compounds, such as nitrates, hydrohalides, sulfates, acetates, etc., are also used.Furthermore, quaternary salts of nitrogen-containing heteroaromatic compounds, nitrogen-containing Oxides of heteroaromatic compounds can also be used.

Examples of 8 bodies include 1-methylvirol, 1-phenylvirol, 1-methylimidazole, l-methylindole, 1-phenylindonyl 11-methylcarbazole, pyridine, 2-chloropyridine, 2-bromopyridine, 2- Fluoropyridine, 4-phenylpyridine, 2
-methylpyridine, 2-methyl-5-ethylpyridine,
2.6-dimethylpyridine, 2.4.6-trimethylpyridine, 2-styrylpyridine.

3-Chlorpyridine, 2,6-dichloropyridine, 2-
10-4-methylpyridine, 2-methoxypyridine,
4.4-dimethylaminopyridine-α-picolinic acid phenyl ester, γ-H:l IJ 7 acid methyl ester, 2.6-dichloropyridine, α-picolinaldehyde, α-picolinamide, 5.6.7. 8-tetrahydroquinoline-2,2'-dipyridyl, quinoline, inquinoline, 2-chloroquinoline, acridine, phenanthridine, benzoquinoline, benzisoquinoline, naphthyridine, pyrazine, 4,6-dimethylvirazine, 2,6
- Dimethylpyrazine, pyridazine, pyrimidine, quinoxaline, 2,3-dimethylquinoxaline, quinaprine, phthalazine, 7enazine, cinnoline, pteridine, etc. These nitrogen-containing heteroaromatic compounds are used as catalysts for other catalysts. It can be added to the reactor separately from the other components, or it can be processed in advance together with other components of the catalyst system to form a suitable compound such as a complex or adduct. It is well known that nitrogen-containing heteroaromatic compounds in particular form complexes with platinum group compounds or Lewis acids. For example, pyridine.

Quinoline, inquinoline, etc., and palladium.

Complexes with halides such as rhodium and platinum, cyanide, and cyanide, specifically Pd (pyridine)
Mention may be made of the palladium(II) chloride-pyridine complex represented by 2C12. Also, pyridine, quinoline,
Complexes of isoquinoline, γ-picoline, etc. with iron, tin, etc., such as Fe(pyridi/) 2 Cdz l Sn
Examples include iron (n) chloride-pyridine complexes and tin (IV) chloride-pyridine complexes represented by (pyridine)2c, d4.

In the method of the present invention, the molar ratio of the platinum element in the catalyst consisting of platinum metal to the aromatic nitro compound can be varied over a wide range;
It may vary over a range of 1:5 to 1:2000, but the preferred range is H1:10 to i:1ooo. Here, the mole has the same meaning as the Durham equivalent b is substituted for a single platinum group metal or its compound.

The Lewis acid used as a co-catalyst has a molar ratio of 1 to 1000 to the platinum group metal or its compound.
1 preferably used in a range of 1:1 to 100:1
Ru. In addition, the amount of nitrogen-containing heteroaromatic compound to be added is
The molar ratio to the platinum group metal or its compound as the main catalyst is in the range of 0.1:1 to 1000:1, preferably 1:1 to 100:1.

In the method of the present invention, it is important to maintain the hydrogen content in the raw material converter gas below a predetermined concentration, and as a result, the production efficiency of the target aromatic urethane is significantly increased, and the pure carbon oxide raw material with the same partial pressure is It reaches the same level as when using . This permissible hydrogen content is 1.0% for the converter gas. Ov
ol %, preferably 0.5 vol, more preferably 0.1 vol % or less. Converter gas composition varies depending on operating standards, but is usually - carbon oxide 55-7
Expressed as a volume ratio of 5 parts, carbon dioxide 10 to 18%, nitrogen 10 to 20 parts, hydrogen 1 to 5 parts, and oxygen 0.1 to 0.6 parts.
〇 There are no particular restrictions on the method of adjusting the hydrogen content to the level 1 or below, and physical methods such as selective adsorption or occlusion of hydrogen, combustion with oxygen, and catalytic dehydrogenation using a palladium catalyst, etc. Chemical methods such as can also be used. Alternatively, it may be obtained by mixing with a gas having a lower hydrogen content.

Although the method of the present invention can be carried out without the presence of a solvent, it may also be carried out diluted with a solvent inert to the reaction. Suitable solvents include n-hexane, benzene, toluene,
Xylene, aliphatic or aromatic hydrocarbons, acetonitrile.

Nitriles such as benzonitrile, aliphatic or aromatic halogenated hydrocarbons such as 1,1°2-trichloro-1,2,2-trifluoroethane, monochlorobenzene, dichlorobenzene and trichlorobenzene, or ketones , ester, tetrahydrofuran, 1,4-
Examples include dioxane, 1,2-dimethoxyethane, etc.
Ru. The reaction is preferably carried out using carbon monoxide and a hydrous acid group compound in at least an equivalent molar amount to the nitro group of the aromatic nitro compound as the main raw material. There are no particular restrictions on the charging method and order of addition of raw materials and catalysts, and they can be changed within the limitations of the equipment used. The reaction is
It may be carried out in batch, semi-continuous or continuous manner.

The reaction temperature is generally maintained in the range of 100 to 250°C, particularly preferably in the range of 14°C to 190°C. The reaction pressure is 10 L as the partial pressure of carbon monoxide.
000 kg/crl G, more preferably 30 to 300 kg/c++t-c. The reaction time varies depending on various factors such as the nature of the aromatic nitro compound used, reaction temperature, reaction pressure, type and amount of catalyst, and reaction equipment, but generally 0.5 to 10 hours is sufficient.

After the reaction is completed, the reaction mixture is cooled to room temperature and depressurized.Then, the reaction product is filtered, distilled, extracted, or
The target aromatic urethane is separated from unreacted products, by-products, solvents, catalysts, etc. by treatment using conventional methods including other suitable separation methods.

The separated and recovered catalyst can be recycled as it is, or after being purified by an appropriate method such as a solvent washing method and having its composition adjusted.

[Examples and comparative examples]

The effects of the present invention will be described below in Examples and Comparative Examples. Converter gases with different hydrogen contents used in the 0 reaction are
Using a palladium molybdenum catalyst synthesized with reference to the method described in No. 0-1549.6, the reaction was adjusted by changing the coexisting oxygen gas supply. All reactions were conducted using a shaking autoclave made of stainless steel. The zero conversion and yield are based on the molar amounts calculated from the results of gas chromatography and high performance liquid chromatography analysis.

(Examples 1 to 4) Nitrobenzene 0.820 &, commercially available 5 weight ratio palladium activated carbon 0.130 g, ferric chloride 0.280 g,
Pyridine 0.290. lit and dehydrated ethanol 10
m1ft internal volume 30Tnl! The gas composition inside the autoclave was 68 qb of carbon monoxide, x x carbon dioxide.
After sufficient replacement with converter gas of 5 tib, nitrogen 14 parts, hydrogen 2.5 parts, and oxygen 0.5 parts, the partial pressure of carbon monoxide was 70 kg/
The autoclave was immersed in a pre-heated oil bath until it became cIIL-G, and the temperature was raised while shaking and stirring, and the reaction was kept at 155-160°C for 2 hours. After the fCo reaction was completed, it was cooled to room temperature, and then evacuated. The insoluble matter was separated, washed with 10 ml of dehydrated ethanol, the yvoF solution and the washing solution were combined, and the products in the solution were analyzed. In Examples 2 to 4, the hydrogen content of the converter gas was 1.4 vol, Q, 8 vol.
% + 0-4 vo1% 0 Nitrobenzene reaction rate (@ and N-phenylcarbamate ethyl (urethane) yield (a) shown in Table 1 0 (Comparative Example 1) Carbon monoxide The reaction was carried out in the same manner as in the example except that a gas having a composition of 70 parts, carbon dioxide 15.5%, nitrogen 14 parts, and oxygen 0.5% was used.The results are shown in Table 1.

(Comparative Example 2) The reaction was carried out in the same manner as in Example except that pure carbon monoxide was used. The results are shown in Table 1. [Effects of the Invention] As described above, according to the present invention, when converter gas adjusted to have a hydrogen content of 1 vol or less is used as a carbon monoxide source, the conventional method Nitrobenzene conversion rates and urethane yields comparable to those using a carbon monoxide source can be obtained and are therefore significantly more economical.

Claims (1)

[Claims] (1) A method for producing an aromatic urethane by reacting an aromatic nitro compound, an organic compound containing carbon oxide and a hydrogen group in a liquid phase in the presence of a platinum group metal catalyst,
- A method for producing aromatic urethane, characterized in that a converter gas with a hydrogen content of 1 vOi% or less is used as a carbon oxide source.