JPH0254818B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing aliphatic isocyanates. More specifically, it relates to a novel method for catalytically producing aliphatic isocyanates by an oxidative carbonylation reaction in which an aliphatic primary amine is reacted with carbon monoxide and molecular oxygen in the presence of an aromatic hydroxyl compound. . [Prior Art] Conventionally, aliphatic isocyanates have been produced by the reaction of aliphatic primary amines with phosgene, but this requires the use of highly toxic phosgene and the use of large amounts of corrosive hydrogen chloride as a by-product. Isocyanates can be produced relatively easily without using phosgene because of the fact that the product may contain hydrolyzable chlorine compounds and it is very difficult to remove this byproduct. A method for manufacturing is desired. On the other hand, it is already known that aliphatic isocyanates can be produced in about 50% yield by reacting aliphatic primary amines with carbon monoxide and stoichiometric amounts of palladium chloride. (EWStern et al., J.
(Org.Chem., Vol. 31, p. 596, 1966) [Problems] However, this method requires more than an equivalent amount of sodium hydrogen phosphate as a dehydrochlorination agent, and palladium chloride is not used as a catalytic reaction. Problems include that the reaction stops due to reduction to metallic palladium, that the reaction time is extremely long (48 to 60 hours), and that the yield is low. Also, Japanese Patent Publication No. 45-650 (and J.Tsuji et al., Chem.Commum. p. 828, 1966
A similar reaction was reported in 2010), but this method also uses stoichiometric amounts of palladium chloride and allyl halide, and the reaction is stopped when palladium becomes a pialyl complex rather than a catalytic reaction. However, it could not be carried out industrially because the yield was very low. The present inventors have discovered various novel catalyst systems that can produce corresponding urethane compounds in good yields by carbonylating amines with carbon monoxide in the presence of an organic hydroxyl compound and an oxidizing agent. Although we have already proposed this reaction system, as a result of further detailed study, we found that the oxidative reaction of aliphatic primary amines was achieved using an aromatic hydroxyl compound with a pKa of 11 or less as the organic hydroxyl compound in the temperature range of 140 to 240°C. The present invention was completed based on the discovery that by carrying out a carbonylation reaction, a carbonylation product rich in isocyanate compounds than in urethane compounds can be obtained in good yield. [Structure] That is, the present invention provides a method for oxidatively carbonylating an aliphatic primary amine with carbon monoxide in the presence of an aromatic hydroxyl compound and molecular oxygen, comprising: (a) a platinum group metal; and (b) an aromatic hydroxyl compound having a pKa of 11 or less. ) A method for producing an aliphatic isocyanate, which is characterized in that a carbonylation reaction product containing an aliphatic isocyanate as a main product is obtained by carrying out the reaction in a temperature range of 140 to 240°C. Although the mechanism of production of isocyanate by the method of the present invention is unknown, the result of the reaction can be expressed by the following general formula. R(NH ₂ ) _o +n・CO+1/2n・O ₂ → R(NCO)n+n・H ₂ O In addition, an aromatic hydroxyl compound (for example, ArOH) having a pKa of 11 or less, which is an essential requirement of the present invention, coexists. Therefore, the following urethanization reaction also occurs. R(NH ₂ )n+n・CO+1/2n・O ₂ +n・ArOH →R(NHCOOAr)n+n・H ₂ O (Here, R is an n-valent aliphatic group, Ar is an aromatic group, and n is 1 or more. The platinum group metals and platinum group element-containing compounds used in the method of the present invention contain at least one component selected from platinum group elements such as palladium, rhodium, platinum, ruthenium, iridium, and osmium. There is no particular restriction as long as these elements are included, and these elements may be in a metallic state or may be components forming a compound. In addition, these catalyst components include, for example, activated carbon, graphite, silica, alumina, silica-alumina,
Supported on carriers such as silica-titania, titania, zirconia, barium sulfate, calcium carbonate, asbestos, pentonite, diatomaceous earth, polymers, ion exchange resins, zeolites, molecular sieves, magnesium silicate, and magnesia. It's okay. Examples of platinum group elements in the metallic state include metals such as palladium, rhodium, platinum, ruthenium, iridium, and osmium, these metal blacks, and catalyst components containing these metal ions on the above-mentioned carrier, and then hydrogen and Those reduced with formaldehyde, alloys or intermetallic compounds containing these metals, etc. are used. Further, the alloy or intermetallic compound may be one of these platinum group metals, or may be one of these platinum group metals, or may contain other elements such as selenium, tellurium, sulfur, antimony, bismuth,
Copper, silver, gold, zinc, tin, vanadium, iron, cobalt, nickel, mercury, lead, thallium, chromium,
It may also contain molybdenum, tungsten, or the like. On the other hand, compounds containing platinum group elements include inorganic salts such as halides, sulfates, nitrates, phosphates, borates, acetates, oxalates,
Organic acid salts such as formates, cyanides, hydroxides, oxides, sulfides, and metal acid salts containing anions such as nitro groups, cyano groups, halogens, and oxalate ions. Examples include metal complex compounds such as ammonia, amines, phosphines, carbon monoxide, salts or complexes containing chelate ligands, and organometallic compounds having organic ligands or organic groups. Among these catalyst components, those containing palladium or rhodium or both are particularly preferred, such as Pd black; Pd black;
-C, Pd- _Al2O3 , Pd- _SiO2 , _Pd - _TiO2 , Pd-
Supported palladium catalysts such as ZrO ₂ , Pd-BaSO ₄ , Pd-CaCO ₃ , Pd-asbestos, Pd-zeolite, Pd-molecular sieve; Pd-Pb, Pd-
Se, Pd-Te, Pd-Hg, Pd-Tl, Pd-P, Pd
−Cu, Pd−Ag, Pd−Fe, Pd−Co, Pd−Ni,
Alloys or intermetallic compounds such as Pd-Rh, these alloys or intermetallic compounds supported on the above-mentioned carriers, PdCl ₂ , PdBr ₂ , PdI ₂ , Pd
(NO ₃ ) ₂ , inorganic salts such as PdSO ₄ , Pd
(OCOCH ₃ ) ₂ , organic acid salts such as palladium oxalate, Pd(CN) ₂ , PdO, PdS, M ₂ [PdX ₄ ], M ₂
Palladate salts represented by [PdX ₆ ] (M represents an alkali metal or ammonium ion, X represents a nitro group, a cyano group, or a halogen), [Pd(NH ₃ ) ₄ ]X ₂ , [Pd(en _{) 2} ] _{Ammine complexes of palladium} such _as
(PR ₃ ) ₃ , Pd (PPh ₃ ) ₄ , PdCl(R) (PPh ₃ ) ₂ , Pd
Complex compounds or organometallic compounds such as (C ₂ H ₄ ) (PPh ₃ ) ₂ , Pd (C ₃ H ₅ ) ₂ (R represents an organic group), Pd
Complex compounds coordinated with chelate ligands such as (acac) ₂ , Ph black, supported rhodium catalysts similar to Pd,
Rh alloys or intermetallic compounds similar to Pd and those supported on carriers, RhCl ₃ and hydrates,
RhBr ₃ and hydrates, RhI ₃ and hydrates, Rh ₂ (SO ₄ ) ₃
and inorganic salts such as hydrates, Rh ₂ (OCOCH ₃ ) ₄ ,
Rh ₂ O ₃ , RhO ₂ , M ₃ [RhX ₆ ] and hydrates (M,
has the same meaning as above), [Rh(NH ₃ ) ₅ ]X ₃ ,
Rhodium ammine complexes such as [Rh(en) ₃ ]X ₃ ,
Rhodium carbonyl clusters such as _Rh4 (CO) ₁₂ , _Rh6 (CO) ₁₆ , [RhCl(CO) ₂ ] ₃ , _RhCl3 ( _PR3 ) ₃ ,
RhCl (PPh ₃ ) ₃ , RhX (CO) L ₂ (X has the same meaning as above, L is a ligand consisting of an organic phosphorus compound and an organic arsenic compound), RhH (CO) (PPh ₃ ) ₃
Examples include complex compounds such as or organometallic compounds. In the present invention, only one type of these platinum group metals or compounds containing platinum group elements may be used, or two or more types may be used as a mixture, and there is no particular restriction on the amount used. , the component containing the platinum group element is usually 0.0001 to 0.0001 to the primary amine.
A range of 50 mol% is desirable. Furthermore, the halogen compound used in the present invention is
It may be either organic or inorganic as long as it is a halogen-containing compound that does not contain platinum group elements.
For example, metal halides, onium halide compounds, compounds capable of producing onium halide compounds in a reaction system, halogen oxoacids or salts thereof, complex compounds containing halogens, organic halides, and the like are preferably used. As the metal halide, particularly preferred are alkali metal and alkaline earth metal halides. Examples of alkali metal and alkaline earth metal halides include lithium chloride, sodium chloride, potassium chloride, calcium chloride, lithium bromide, sodium bromide, rubidium bromide, cesium bromide, magnesium bromide, strontium bromide, Combining a single metal such as barium bromide, lithium iodide, sodium iodide, potassium iodide, rubidium iodide, cesium iodide, magnesium iodide, calcium iodide, strontium iodide, barium iodide, etc. with a single halogen Compounds, double salts such as sodium magnesium chloride, potassium magnesium bromide, potassium bromine fluoride, potassium iodine chloride, rubidium iodine chloride, cesium iodine chloride, cesium iodine chloride bromide, rubidium iodine chloride bromide, potassium iodine bromide, Examples include polyhalides such as cesium iodine bromide and rubidium iodine bromide. An onium halide compound is a compound containing an element with a lone pair of electrons, in which a proton or other cationic reagent is bonded to these lone pairs, and the element with a lone pair of electrons forms a covalent bond with a valence of 1.
increases and becomes a cation,
It has a halogen anion as a counter ion. Such onium compounds include ammonium compounds ([R ¹ R ² R ³ R ^{4 N} ]X), phosphonium compounds ([R ¹ R ² R ³ R ^{4 P} ] Particularly preferred are R ³ R ⁴ As]X), iodonium compounds ([R ¹ R ² I]X), and the like. Here, R ¹ , R ² , R ³ , and R ⁴ represent hydrogen or a group selected from an aliphatic group, an aromatic group, an alicyclic group, an araliphatic group, and a heterocyclic group, and each is the same. Alternatively, in some cases, it may be a constituent element of a ring containing an element having a lone pair of electrons. Further, X represents a halogen selected from Cl, Br, and I. Of course, it may be a compound having two or more such onium groups in its molecule, or it may be a polymer containing such onium groups in its main chain or side chain. Halogenated onium compounds, which are onium compounds whose anion is a halogen, can be easily synthesized by reacting a hydrogen halide or an organic halide with a corresponding amine or nitrogen-containing compound, phosphine compound, alumine compound, etc. These may be produced outside the reaction system, or may be produced within the reaction system. Of course, it may be produced by other methods, or may be produced within the reaction system by other methods. Among these, particularly preferred are halogenated ammonium compounds and halogenated phosphonium compounds. Ammonium halide compounds are produced by the reaction of the corresponding nitrogen-containing compound with hydrogen halide,
It can be easily obtained by reacting a nitrogen-containing compound with an alkyl halide or an aryl halide. Examples of such nitrogen-containing compounds include ammonia, primary amines, secondary amines, tertiary amines, etc. Examples include amines such as amines, hydroxylamines, hydrazines, hydrazones, amino acids, oximes, imidoesters, amides, and various nitrogen-containing heterocyclic compounds. Examples of quaternary ammonium halides include aliphatic quaternary ammonium halides such as halogenated tetramethylammonium, halogenated tetraethylammonium, halogenated tetrabutylammonium, halogenated trimethylethylammonium, and halogenated diethyldibutylammonium; Alicyclic quaternary ammonium halides such as N,N,N-trimethylcyclohexylammonium, aromatic aliphatic quaternary ammonium halides such as halogenated tetrabenzylammonium, halogenated trimethylbenzylammonium, halogenated N,N, N-trimethylphenylammonium, aromatic quaternary ammonium halides such as halogenated N,N,N-triethylphenylammonium, halogenated N-methylpyridinium, halogenated N-ethylquinolinium, halogenated N, Heterocyclic quaternary ammonium halides such as N-dimethylpiperidinium and halogenated N,N'-dimethylimidazolinium are preferably used. Examples of the halogenated phosphonium compounds include symmetrical tetraalkylphosphonium compounds such as halogenated tetramethylphosphonium, halogenated tetraethylphosphonium, and halogenated tetrabutylphosphonium, and asymmetrical halogenated ethyltrimethylphosphonium and halogenated diethyldimethylphosphonium compounds. Tetraalkylphosphonium compounds, symmetrical tetraarylphosphonium compounds such as halogenated tetraphenylphosphonium, halogenated tetra(p-tolyl)phosphonium, etc., asymmetrical tetraarylphosphonium compounds such as halogenated (α-naphthyl)triphenylphosphonium, etc. halogenated methyltriphenylphosphonium, alkylaryl mixed phosphonium compounds such as halogenated phenyltrimethylphosphonium, and tetraalkylphosphonium compounds such as halogenated tetrabenzylphosphonium. Halogen oxoacids and their salts refer to halogen oxyacids and their salts with positive oxidation numbers of 1, 3, 5, and 7, and specifically include hypochlorous acid, chlorous acid, and chloric acid. , perchloric acid, hypobromite, bromate, perbromate, hypoiodic acid, iodic acid, iodic acid,
Orthoperiodic acid, metaperiodic acid, and salts of these acids. As a salt cation,
Any ions such as ammonium ions and various metal ions may be used, but alkali metal ions and alkaline earth metal ions are particularly preferred. Among these salts are salts of bromite, such as sodium bromite; lithium bromate, sodium bromate, potassium bromate, rubidium bromate,
Bromates such as cesium bromate, magnesium bromate, and calcium bromate; perbromates such as potassium perbromate, sodium hypoiodite, potassium hypoiodite, rubidium hypoiodite,
Hypoiodates such as cesium hypoiodate, calcium hypoiodite, barium hypoiodate, lithium iodate, sodium iodate, potassium iodate, potassium hydrogen iodate, rubidium iodate, cesium iodate, Iodates such as magnesium iodate, calcium iodate, strontium iodate, barium iodate; lithium periodate, sodium metaperiodate, trisodium orthoperiodate dihydrogen, disodium trihydrogen orthoperiodate, Periodates such as potassium meta-periodate, dipotassium trihydrogen orthoperiodate, tripotassium hydrogen dimesoperiodate, rubidium periodate, cesium periodate, and barium periodate are preferably used. Complex compounds containing halogens are cationic,
Any anionic halogen-containing complex compound may be used, such as polyhalogenated halogen acid salts such as ammonium dichlorobromate, tetramethylammonium tetrabromoiodate, potassium hexaiodotellurate, tetraethylammonium tetraiodomercurate, Metal halides such as potassium tetraiodobismuthate, sodium tetrabromocuprate, cesium tetrabromoferrate, barium hexaiodostannate, potassium tetraiodopate, potassium hexabromotellurate, tris(pyridine)chromium tribromide, tris( Complexes having a ligand such as pyridine) molybdenum triiodide, hexaammine cobalt tribromide, and bis(2,2'-pipyridine) copper diiodide are used. In addition, organic halides have the general formula R ⁶ (X)m (wherein, R ⁶ is an m-valent organic group, X is a halogen, m
means an integer greater than or equal to 1. ), and when m is 2 or more,
X may be two or more different halogen species. In addition, halogen X is a heteroatom other than carbon,
For example, it may be bonded with nitrogen, phosphorus, oxygen, sulfur, selenium, etc. Furthermore, halogen molecules themselves can also be used. Such halogen compounds may be used alone or in combination of two or more. Such a halogen compound is generally used in an amount of 0.001 to 10,000 times, preferably 0.1 to 100 times, the amount of metal in the platinum group metal or compound containing a platinum group metal element. . Among the halogen-containing compounds used in the method of the present invention, those in which the halogen species is bromine or iodine are preferred, and those containing iodine are particularly preferred. The aromatic hydroxyl compound used in the present invention may be any compound as long as it has a hydroxyl group directly bonded to an aromatic group and has a pKa of 11 or less. For example, phenol; various alkylphenols such as cresol (each isomer), xylenol (each isomer), ethylphenol (each isomer), propylphenol (each isomer); methoxyphenol (each isomer),
Various alkoxyphenols such as ethoxyphenol (each isomer); halogenated phenols such as chlorphenol (each isomer), bromophenol (each isomer), dichlorophenol (each isomer), and dibromophenol; methylchlor Phenol (each isomer), ethyl chlorophenol (each isomer), methylbromophenol (each isomer),
Alkyl and halogen-substituted phenols such as ethylbromophenol; Formula [A is a simple bond, -O-, -S-, _-SO2
-, -CO-, -CH ₂ -, -C(R')- (R' is a lower alkyl group), and the aromatic ring represents a halogen, alkyl group, alkoxy group, or ester group. , an amide group, a cyano group, or the like. ] various substituted phenols; naphthol (each isomer) and various substituted naphthols; heteroaromatic hydroxyl such as hydroxypyridine (each isomer), hydroxycoumarin (each isomer), hydroxyquinoline (each isomer) Compounds: Aromatic dihydroxy compounds such as hydroquinone, resorcinol, catechol, dihydroxynaphthalene, dihydroxyanthracene and their alkyl-substituted or halogen-substituted dihydroxy compounds; Formula (A is as described above, and the aromatic ring may be substituted with a substituent such as a halogen, an alkyl group, an alkoxy group, an ester group, an amide group, or a cyano group.) Nitro-substituted aromatic hydroxyl compounds such as nitrophenol (each isomer) and nitronaphthol (each isomer); cyanophenol (each isomer), cyanonaphthol (each isomer), etc. are used. Such aromatic hydroxyl compounds may be used alone or in combination of two or more. In the present invention, by using such aromatic hydroxyl compounds having a pKa of 11 or less, If an aromatic hydroxyl compound with a pKa greater than 11 is used, a carbonylation product containing a urethane compound as a main component can be obtained. In this sense, more preferable aromatic hydroxyl compounds are those whose pKa
is 10.5 or less. The aromatic hydroxyl compound is preferably used in such a manner that the number of hydroxyl groups is 1 mol or more per 1 mol of amino groups of the primary amine used. More preferably, the amount of hydroxyl group used is 5 moles or more, and even more preferably 10 moles or more, per 1 mole of amino group. If the amount of the aromatic hydroxyl compound is less than 1 mol per amino group of the primary amine, a urea compound will be produced as a by-product, which is not preferable. The aliphatic primary amine used in the present invention is 1
Any amine having one or more primary amino groups bonded to an aliphatic carbon atom may be used, and may be an alicyclic primary amine or an aromatic aliphatic primary amine. Examples of such aliphatic primary monoamines or polyamines include methylamine, ethylamine, propylamine (each isomer), butylamine (each isomer), pentylamine (each isomer), hexylamine (each isomer), Aliphatic primary monoamines such as dodecylamine (each isomer); ethylenediamine, diaminopropane (each isomer), diaminobutane (each isomer), diaminopentane (each isomer), diaminohexane (each isomer), Aliphatic primary diamines such as diaminodecane (each isomer);
1,2,3-triaminopropane, triaminohexane (each isomer), triaminononane (each isomer), triaminododecane (each isomer), 1,8-
Diamino-4-aminomethyl-octane, 2,6
-diaminocaproic acid 2-aminoethyl ester, 1,3,6-triaminohexane, 1,6,
Aliphatic primary triamines such as 11-triaminoundecane, cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, diaminocyclobutane, diaminocyclohexane (each isomer), 3-aminomethyl-3,5,
Alicyclic primary mono- and polyamines such as 5-trimethylcyclohexylamine, triaminocyclohexane (each isomer); benzylamine, di(aminomethyl)benzene (each isomer), aminomethylpyridine (each isomer), These include aromatic aliphatic primary mono and polyamines such as di(aminomethyl)pyridine (all isomers), aminomethylnaphthalene (all isomers), and di(aminomethyl)naphthalene (all isomers). In addition, in the aliphatic groups, alicyclic groups, and aromatic aliphatic groups that make up the skeletons of these primary amines, some of the hydrogens are halogens, alkyl groups, alkoxy groups, aryl groups, cyano groups, and esters. It may be substituted with a substituent such as a group or a sulfone group, or the skeleton may contain an unsaturated bond, an ether bond, an ester bond, a thioether bond, a sulfone bond, a ketone bond, etc. In the method of the present invention, it is preferable to use an aromatic hydroxyl compound as a solvent, but other suitable solvents can also be added. Examples of such solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and decane; alicyclic hydrocarbons such as cyclohexane, tetralin, and decalin; and aromatic solvents such as benzene, toluene, xylene, and mesitylene. Group hydrocarbons; Nitriles such as acetonitrile and benzonitrile;
Sulfones such as sulfolane, methylsulfolane, dimethylsulfolane; tetrahydrofuran,
Examples include ethers such as 1,4-dioxane and 1,2-dimethoxyethane; ketones such as acetone and methyl ethyl ketone; and esters such as ethyl acetate and ethyl benzoate. Furthermore, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, fluorobenzene, chlorotoluene, chlornaphthalene, and bromnaphthalene; chlorhexane, chlorocyclohexane, trichlorotrifluoroethane, methylene chloride, and tetrachloride; Halogenated aliphatic hydrocarbons such as carbon or halogenated alicyclic hydrocarbons are also used as solvents. The molecular oxygen used in the present invention includes pure oxygen or oxygen, and may be air.
Alternatively, air or pure oxygen may be diluted by adding another gas that does not inhibit the reaction, such as an inert gas such as nitrogen, argon, helium, or carbon dioxide. In some cases, it may also contain gases such as hydrogen, carbon monoxide, hydrocarbons, and halogenated hydrocarbons. Further, in the method of the present invention, it is necessary to carry out the reaction at a temperature range of 140 to 240°C. 140
If the reaction is carried out at a temperature lower than 0.degree. C., the amount of urethane compounds and urea compounds increases, the reaction is slow, or almost no reaction occurs, which is not preferable. Also, if the reaction is carried out at a temperature higher than 240℃,
This is not preferred because side reactions increase and the yield of isocyanate decreases. In this sense,
A more preferred temperature range is 150-190°C. The reaction pressure is 1 to 500Kg/cm ² , preferably 20
~300 Kg/cm ² , and the reaction time varies depending on the reaction system, catalyst system, and other reaction conditions, but is usually several minutes to several hours. The reaction of the present invention can be carried out either batchwise or continuously, in which reaction components are continuously supplied and a reaction solution is continuously withdrawn. In the method of the present invention, other additives can be added to the reaction system as necessary in order to carry out the reaction more efficiently. Particularly preferred as such additives are those having a dehydrating effect, such as molecular sieves. Next, the present invention will be explained in more detail with reference to Examples. [Example] Example 1 In a stirred autoclave with an internal volume of 200 ml, 12.5 mmol of hexamethylene diamine and 47 mmol of phenol were added.
g, palladium black 0.5 mgatom, and sodium iodide 1 mmol were added, and after replacing the system with carbon monoxide, carbon monoxide was 75 Kg/cm ² and then air was 35 Kg/cm ²
was added to make the total pressure 110Kg/cm ² . 170 while stirring
After reacting at °C for 1 hour, the entire amount of palladium black was separated and recovered by filtering the reaction mixture. Analysis of the reaction mixture showed that the reaction rate of hexamethylene diamine was 100%, the yield of hexamethylene diisocyanate was 73%, and the monoisocyanate monourethane 1-isocyanato-6-phenoxycarbamoyl -14% hexane
It was found that 1,6-diphenoxycarbamoyl-hexane, which is a diurethane, was produced in a yield of 7%. Note that when sodium iodide was not used, the reaction hardly proceeded. Example 2 The same reaction as in Example 1 was carried out except that 54 g of para-cresol was used instead of phenol. As a result,
The reaction rate of hexamethylene diamine was 100%, and the yield of hexamethylene diisocyanate was 62%.
-Isocyanate-6-(p-methylphenoxy)
Carbamoyl-hexane with a yield of 3% and di-(p
-Methylphenoxy)carbamoyl-hexane was found to be produced in a yield of 30%. Example 3 Parachlorophenol 55g instead of phenol
As a result of performing the same reaction as in Example 1 except for using , the reaction rate of hexamethylene diamine was 100%.
The yield of hexamethylene diisocyanate is 75%.
1-isocyanato-6-(p-chlorophenoxy)carbamoyl-hexane with a yield of 15%,
It was found that di-(p-chlorophenoxy)carbamoyl-hexane was produced in a yield of 4%. Examples 4 to 11 Reactions were carried out in the same manner as in Example 1 except that various halogen compounds shown in Table 1 were used in place of sodium iodide. The results are shown in Table 1.

【table】

〔effect〕

Thus, by reacting an aliphatic primary amine with carbon monoxide and oxygen in the presence of a specific aromatic hydroxyl compound and a specific catalyst system at a certain temperature range, aliphatic isocyanates can be directly produced. It is completely new and surprising that it can be produced catalytically.

Claims (1)

[Scope of Claims] 1. A method for oxidatively carbonylating an aliphatic primary amine with carbon monoxide in the presence of an aromatic hydroxyl compound and molecular oxygen, comprising: (a) a platinum group metal and platinum; (c) using a catalyst system comprising at least one compound selected from compounds containing group elements and at least one halogen compound; and (b) an aromatic hydroxyl compound with a pKa of 11 or less. 1. A method for producing an aliphatic isocyanate, which comprises obtaining a carbonylation reaction product containing an aliphatic isocyanate as a main product by carrying out the reaction in a temperature range of ~240°C. 2 A platinum group metal and a compound containing a platinum group element,
The method according to claim 1, which is palladium, rhodium, palladium compounds and rhodium compounds. 3. The halogen compound contains a halogen molecule, an alkali metal or alkaline earth metal halide, a halogenated onium compound or a compound capable of producing these compounds in a reaction system, a halogen oxoacid or its salt, or a halogen ion. The method according to claim 1, wherein the compound is at least one selected from complex compounds and organic halides. 4. The method according to claim 2, wherein the platinum group metal and the compound containing a platinum group metal element are palladium or a compound containing palladium. 5. The method according to claim 1 or 3, wherein the halogen compound is a bromine molecule, an iodine molecule, or a compound containing bromine or iodine. 6. The method according to claim 5, wherein the compound containing bromine or iodine is an alkali metal or alkaline earth metal bromide or iodide. 7. The method according to claim 1, wherein the halogen compound is an alkali metal iodide. 8. The method according to claim 1, wherein the halogen compound is a tetraalkylammonium iodide compound. 9. The method according to claim 1, which uses an aromatic hydroxyl compound having a pKa of 10.5 or less. 10. The method according to claim 1, which is carried out at a temperature range of 150 to 190°C. 11. The method according to claim 1, wherein the aliphatic primary amine is a diamine. 12 Claim 1 wherein the diamine is hexamethylene diamine and the aliphatic isocyanate produced is hexamethylene diisocyanate.
The method described in section.