CA1192570A - Process for the preparation of urethanes - Google Patents
Process for the preparation of urethanesInfo
- Publication number
- CA1192570A CA1192570A CA000407331A CA407331A CA1192570A CA 1192570 A CA1192570 A CA 1192570A CA 000407331 A CA000407331 A CA 000407331A CA 407331 A CA407331 A CA 407331A CA 1192570 A CA1192570 A CA 1192570A
- Authority
- CA
- Canada
- Prior art keywords
- urea
- compound
- reaction
- catalyst
- compounds
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C269/00—Preparation of derivatives of carbamic acid, i.e. compounds containing any of the groups, the nitrogen atom not being part of nitro or nitroso groups
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Catalysts (AREA)
Abstract
PROCESS FOR THE PREPARATION OF URETHANES
ABSTRACT OF THE DISCLOSURE
Urethanes are prepared by reacting a substituted or unsubstituted urea having at least one hydrogen atom attached to a urea nitrogen atom with an organic compound containing at least one hydroxyl group and carbon monoxide in the presence of molecular oxygen and a catalyst system.
The catalyst system includes a noble metal catalyst and oxidizing quinoid compounds or compounds capable of being converted into oxidizing quinoid compounds. This reaction is generally carried out at a temperature of 100 to 300°C and a pressure from 5 to 500 bar. The urethanes thus produced are particularly useful in the production of isocyanates and pesticides.
ABSTRACT OF THE DISCLOSURE
Urethanes are prepared by reacting a substituted or unsubstituted urea having at least one hydrogen atom attached to a urea nitrogen atom with an organic compound containing at least one hydroxyl group and carbon monoxide in the presence of molecular oxygen and a catalyst system.
The catalyst system includes a noble metal catalyst and oxidizing quinoid compounds or compounds capable of being converted into oxidizing quinoid compounds. This reaction is generally carried out at a temperature of 100 to 300°C and a pressure from 5 to 500 bar. The urethanes thus produced are particularly useful in the production of isocyanates and pesticides.
Description
57~
~o-2379 LeA 21,183 PROCESS F3R THE P~EP~R~TION OF UREr~HANES
BACKGROUND OF TT~E IN~ENTION
. _ . _ The present invention relates to a process for the preparation of urethanes (carbamic acid esters or carba-5 mates) by the reac-tion of ureas with organic hydroxyl compounds and carbon monoxide in the presence of molecu-lar oxygen and of a catalyst system. ~he catalyst sys-tem comprises at least one noble metal or at least one noble metal compound and a quinoid compound or a compound 10 capable of being converted into quinoid compounds.
Organlc isocyanates are generally prepared on a large scale by reactlon of the corresponding amines with phosgene. Due to the high chlorine requirement and conse-quent high energy costs for the preparation of phosgene, lS a method for commercially producing organic isocyanates that would not require the use of phosgene has long been sought.
One approach taken in searching for a method for phosgene free preparation of low molecular weight ure-20 thanes is thermal cleavage. Numerous methods for thepreparation of urethanes which are capable of such cleavaqe have been proposed. German Offenlegungsschriften No. 2,908,250, No. 2,908,251 and No. 2,910,132 and U.S.
Patents 4,260,781 and 4,266,070 r for example, describe 25 the preparation of urethanes from primary amines, carbon monoxide and organic hydroxyl compounds in the presence of oxidizing agents. In U.S. Patent 4,266,070, the oxidl-zing agents are quinones used in the absence of oxygen and the catalysts used are carbonyl compounds. Such 30 carbonyl compounds are difficult to handle.
Another method for obtaining urethanes capable of undergoing cleavage to form isocyanates is by reaction Mo-2379 o~ N,N'-disubstituted ureas with compounds containing hydroxyl groups and carbon monoxide in the presence of suitable oxidizing agents. According to German Offenle-gungsschrift No. 2,908,252, oxidizin~ agents useful in this reaction are nitro comoounds or molecular oxygen, alone or in combination wlth ni~ro compounds. This reaction described in ~erman Offenlegungsschrift 2,908,252 proceeds in arcordance with the following general reaction scheme (1):
o 10 Equation (1) 2 Rl-NH-C~NH-R + R -NO2 ~ 5 R OH + 3 CO
O O O
.. .. ..
~o-2379 LeA 21,183 PROCESS F3R THE P~EP~R~TION OF UREr~HANES
BACKGROUND OF TT~E IN~ENTION
. _ . _ The present invention relates to a process for the preparation of urethanes (carbamic acid esters or carba-5 mates) by the reac-tion of ureas with organic hydroxyl compounds and carbon monoxide in the presence of molecu-lar oxygen and of a catalyst system. ~he catalyst sys-tem comprises at least one noble metal or at least one noble metal compound and a quinoid compound or a compound 10 capable of being converted into quinoid compounds.
Organlc isocyanates are generally prepared on a large scale by reactlon of the corresponding amines with phosgene. Due to the high chlorine requirement and conse-quent high energy costs for the preparation of phosgene, lS a method for commercially producing organic isocyanates that would not require the use of phosgene has long been sought.
One approach taken in searching for a method for phosgene free preparation of low molecular weight ure-20 thanes is thermal cleavage. Numerous methods for thepreparation of urethanes which are capable of such cleavaqe have been proposed. German Offenlegungsschriften No. 2,908,250, No. 2,908,251 and No. 2,910,132 and U.S.
Patents 4,260,781 and 4,266,070 r for example, describe 25 the preparation of urethanes from primary amines, carbon monoxide and organic hydroxyl compounds in the presence of oxidizing agents. In U.S. Patent 4,266,070, the oxidl-zing agents are quinones used in the absence of oxygen and the catalysts used are carbonyl compounds. Such 30 carbonyl compounds are difficult to handle.
Another method for obtaining urethanes capable of undergoing cleavage to form isocyanates is by reaction Mo-2379 o~ N,N'-disubstituted ureas with compounds containing hydroxyl groups and carbon monoxide in the presence of suitable oxidizing agents. According to German Offenle-gungsschrift No. 2,908,252, oxidizin~ agents useful in this reaction are nitro comoounds or molecular oxygen, alone or in combination wlth ni~ro compounds. This reaction described in ~erman Offenlegungsschrift 2,908,252 proceeds in arcordance with the following general reaction scheme (1):
o 10 Equation (1) 2 Rl-NH-C~NH-R + R -NO2 ~ 5 R OH + 3 CO
O O O
.. .. ..
2 Rl-N~-C-OR4 ~ 2 R2-NH-c-oR4 ~ R3-NH-c-oR ~ 2 H~O
wherein Rl, R , R3 and R4 represent alkyl or aryl groups~
15 When molecular oxygen is used as the oxidizing agent, the reaction takes place in accordance with the following equation (Z):
o Equation (2) R -NH-C-NH-R + 2 R -OH + CO ~ 1/2 2 , Rl-NH-C-oR4 + R2-NH-C-oR4 + H20 From these equations it is readily seen that one disad-vantage of usiny nitro compounds as oxidizing agents is the formation of a mixture of urethanes which must be 25 separated (e.g. by distil]ation). ~litro compounds are therefore useful oxidizing agents only when substituen-ts Rl, R2 ~ R3 are identical because only then will the formation of a mixture of urethanes be avoided. It is rare, however, that both, the appropriate urea compound 30 and the nitro compound which corresponds to this urea compond are simultaneously available for the reaction on a large commercial scale.
Mo-2379 Aside from the nature of the oxidlzin~ agent, another disadvantage of the process disclosed in German Offenle--gungsschrift ~lo. 2,980,25~ lies in the ract that rela~
tively large quantities of inorganic or organic halides 5 must be used as cocatalysts. These halides are hiqhlv corrosive. They also impair the process when carried out on a commercial scale because they are largely insoluble in the reaction environment.
SUMMA:RY OF THE INVE~TION
It is an ohject of the present invention to provide ;an imprcved p-~ocess for the production of urethanes.
It is another object of the present invention to provide a process for the production of urethanes in which very little, if any, insoluble and corrosive catalyst 15 is required.
These and other objects which will ~e apparent to those skilled in the art are accompllshed by reacting a urea having at least one hydrogen atom bonded to a urea nitrogen atom, an organic compound containing at least 20 one hydroxyl group and carbon mono~ide in the presence of molecular oxy~en and a catalyst system. The catalyst system is made up of (i) a noble metal and/or a comPound of a noble metal and (ii) at least one quinoid compound having an oxidizing effect on the reactants resp.on oxi-dizable catalyst components and/or atleast one compound capable of being converted into an oxidizing quinoid compound under reaction conditions. The catalyst system may also include tertiarv amines and/or magnesium compounds and/or compounds of elements from groups III A to V A and I }3 to VIII B of the Periodic System of Elements. The reaction is generally carried out at a temperature of from 100 to 300C and a pressure from 5 to 500 bar.
Mo-2379 S'7~
DETAILED DESCRIPTION OF THE INVEN~ION
~ he present invention relates ~o a process for the preparation of urethanes by reactinq an unsubstituted or substituted urea containin~ at least one hydrogen atom 5 attached to a urea ni-trogen atom with an organic compound containing at least one hydroxyl group and carbon monoxi.de in the presence of molecular oxygen and a catalyst system.
The catalyst syste~ is made up of (i) at least one noble metal and~or a compound of a noble metal of the Eighth 10 Sub-group of the Periodic System of Elements, and (ii) at least one quinoid compound having an oxidizing action and/or at least one compound capable of being converted into an oxidizing quinoid compound under the reaction conditions~
Suitable ureas are any organic compounds having at least one structural unit of the formula H - N - CO - N -in which the free valencies are saturated by hydrogen a-toms or by organic substituents whieh are preferably 20 inert under the reaction conditions. Examples oE such ureas include urea itself or substituted ureas corre sponding to the formulae (I), (II), (III):
~ ~ 5 N-C-N N---C- ,N N C-N X
25 ~1 x2 ~ X4 ~ Xl (I) (II) (III) in which Xl, X2, and X3 (which may be the same or differ-30 ent) represent hydroqen or any organie group which is inert under the reaction conditions, such as aliphatic hydrocarbon groups havinq from 1 to 4 earbon atoms or Mo-2379 aromatic hydrocar~on groups ha~ing from 6 to 10 carbon atoms. The di~alent substituent X4 and the two nitrogen atoms of the urea group together form an a-t least 5-membered heterocyclic ring having at least one (prefer-5 ably 2 to 6) carbon atoms arranged within the ring andoptionally hetero atoms additionally present in the ring.
The divalent substituent X5 forms a heterocyclic ring (preferably 5- or 6- membered) with one of the nitrogen atoms of the urea group as rlng member, and in addition 10 to at least two carbon atoms axranged within the ring i-t may ha~e other hetero atoms arranged within the ring.
All oE the substituents Xl through X may be substi-tuted or interrupted by difunctional groups. Sui-ta~le substituents or difunctional groups include halogen atoms, 15 keto groups, sulfoxide groups, sulfone g~oups, ether groups, carboxylic acld esters and nitro groups. Other urea grouPs may also be functional groups, i.e.one molecule of the starting urea may contain more than one urea group. If these additional urea groups are of the type depicted in 20 general formulae I, II, or III, they are also converted into urethane groups in accordance with the present inven-tion. If the urea starting material contains one or more amino groups, these amino groups are also converted into urethane groups under the reaction conditions described 25 in German Offenlegungsschrift No. 3,0~,982. The molecu-lar weights of suitable urea starting materials generally range from 60 to 600.
The urea compound used as the starting material is preferably a urea correspondlng to formula (I) and/or (II) 30 which is sy~metrically substituted. It is particularly preferred to use N,N'-disubstituted ureas of formula ~I) in which the two su~stituents are identical groups, particularly Cl C4-al~yl groups or a phenyl group. Unsub-stituted urea is also suitable.
Mo~2379 ~2~'7~
Specific examp].es of suitable urea s-tarting materials include: urea, N-tert.-butylurea, N,N dimethvlurea, N,N'-dimethylurea, N-phenyl-N,N'-dimethyl-urea, tris (2-chlorophenyl)-urea, 6-nitxo-1-naphthylurea, 3~amino-5 4-methyl-phenylurea, 2-imidazolidinone, 1,4-butylene-bis-urea, N,N-pentamethylene-urea, N,N'-bis-(2-furyl)-urea, l-oxa-6,8-diazacyclododecanone-7, and N,N'-2,2'-bipheny-lene urea. Preferred urea star-ting materials include:
urea, N,N'-dimethylurea, N,N'-dicyclohexyl-urea, N,N'-10 diphenylurea, N,N'~bis-(p-tolyl)-urea, ~,N'-bis-(2-amino-phenyl)-urea, N,N'-bis-(4-nitrophenyl)-urea and N,N'-bis-(4-chlorophenyl)-urea. N,N'-dimethylurea and ~,N'-diphenylurea are particularly preferred.
The hydroxyl group-containing starting material may 15 be any organic compound containing hydroxyl groups, in particular a monohydric or higher hydric alcohol or a monohydric or higher hydrlc phenol. Compounds which are saturated monohydric aliphatic alcohols in the molecular weight range of from 32 to 300 containing primary hydroxyl 20 groups or monovalent phenols with a maximum molecular weight of 300 are particularly preferred.
The alcohol starting material may be any straight chained or branched monohydric or polyhydric alkanol, alkenol, cycloalkanol, cycloalkenol or aralkyl alcohol.
25 These alcohols may contain inert substituents. Suitable inert substituents include halogen atoms, sulfoxide groups, sulfone groups, nitro groups, carbonyl groups and carbox~
ylic acid ester groups. ~lcohols having ether bridges are also suitable. Specific examples of suitable alcohols are:
30 Methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, n-hexanol, cyclohexanol, benzyl alcohol, chloro-ethanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, hexanetriol and trimethylolpropane. Monohydric aliphatic alcohols having 35 from 1 to 6 carbon atoms are particularly preferred.
Mo-2379 Suitable phenols include: phenol, 2-isopropox~-phenol, 7-hydroxy-2, 2-dimethyl-2,3-dihydrobenzofuran, the isomeric chlorophenols, cresols, ethylphenols, propyl-phenols, bu~ylphenols or higher alkylphenols, pyrocate-5 chol, 4,4' dihydroxy-diphenylmethane, bisphenol-A, anthra~
nol, phenanthrol, pyroyallol, phloroglucinol or 8-quino~
linol. Preferred mononuclear phenols having up to 12 carbon atoms and dinuclear phenols having up to 18 carbon atoms are preerable.
In carrying out the process accoxding to the inven-tion, the hydroxyl group-containing starting material is generally used in a quantity such that from 2 to 200, preferably from 2 to 100 mol of hydxoxyl groups are pre-sent for each mol of urea groups of the urea star-ting 15 material present in the reaction mixture. Since relatively inexpensive hydroxyl compounds which are liquid under the reaction conditions are generally used, they are preferably used in excess within the ranges mentioned. The excess hydroxyl compound then serves as the reaction medium (solvent).
Carbon monoxide is also used as a reactant in the process of the present invention. This starting material is generally used in a quantity such that from 0.5 to 30 mol of carbon ~onoxide is present for each mol of urea 25 group in the urea starting material. If primary amlno groups are also to be converted into urethane groups (according to German Offenlegungsschrift No. 3,046,982), at least one additional mol of carbon monoxide must be provided for each mol of amino group to be reacted.
The oxidizing agent used in the present invention may be molecular oxygen in the pure form or in the form of a mixture with an inert gas such as nitrogen, carbon dioxide, or preferably aix. In the presence of molecular oxygen, oxycarbonylation takes place (i.e., the reaction 35 proceeds as shown in equation (2)) or, in the case of Mo-2379 ~a~s~7~
symmetrically su~stltuted urea starting materials, the reaction may proceed in the manner shown in equation (3):
H ~ H
Equation (3) R -N-C-N-Rl + 2 R4-oH ~ CO + l2 2 H O
2 R -N-C-oR4 + H2O
It ls readily seen from this equatlon, that 1/2 mol of carbon monoxide and l/4 mol of molecular oxygen are re-quired ror each urethane group formed in tha described 10 reaction. Molecular oxygen is generally used in a quantity ranging from approximately stoichiometric to approximately 5 times the stoichiometric amount (based on the urea groups to be reacted). If the hydroxyl group containing starting material used is sensltive to ox~di-15 zing agen-ts, it is often advisable to use the oxy~en oxidizing agent in less than the equivalen~ quantity, (based on the urea groups of the urea starting material).
It may therefore be appropriate to use oxygen in a quan-tity which is only 60 to 100% of the equivalent quantity 20 when hydroxyl group-containing starting materials which are sensitive to oxidation are used. In such cases where less than a stoichiometric quantity of oxygen is used, the loss in yield due to use of such a lesser amount is much smaller than the loss due to formation of unwanted 25 oxidation productsO Moreover, when subequivalent quan-tities of oxygen are used,unreacted starting materlals may be easily recovered and used again whereas alcohol destroyed by unwanted oxidation reactions cannot be recovered.
The oxidizing agent employed in the present invention may in principle be any inorganic, largely ionic compound which has an oxidizing action, particularly salt-type compounds of metals in higher valency stages. Organic Mo-2379 .
oxidizing agents, in particular quinones, are also suitable in principle. All of these oxidizing agents are, however, less suitable than oxygen. Organic nitro compounds are no-t suitable oxidizing agents in the process of the 5present in-~ention.
The process of the present invention must be carried out in the presence of a catalyst sys-tem. This catalyst system is made up of (i) at least one noble metal and/or at least one compound of a noble metal of the Eighth lOSub-group of ~he Periodic System of Elements and (ii) at least one quinoid compound having an oxidizing action and/or at least one compound capable of being convertecl into an oxidizing quinoid compound under the reaction conditions.
Catalyst component (i) may be either a noble metal of the Eighth Sub-group of the Periodic Sys~em or a som-pound of such a metal. It is particularly advantageous to use a noble metal compound which is soluble in the reac-tion mixture, such as a chloride, bromide, iodide, 20chlorine complex, bromine complex~ iodine complex, ace-tate, acetyl acetonates or other soluble noble metal compounds. Preferred noble metals are palladium, ruthen-ium and rhodium. Palladium is particularly preferred, especially in the form of soluble palladium chloride or 25 palladium acetate.
Preferred concentrations for catalyst co~ponent (i) are generally from 3 to 1000 ppm (preferably from 5 to 100 ppm), calculated as noble metal and based on the whole reaction mixture, including any solvent used.
30 Although higher concentrations o noble metal could be used, such concentrations are uneconomical due to possible loss of noble metal, particularly since they do not increase the yield o urethane.
Catalyst component (ii) is a quinoid compound Mo-2379 q ~
havlng an oxidi~ing action and/or a compound capable of being con~erte.d into an oxidizing quinoid compound un~er the reaction conditions. By "quinoid co~pounds" are ~eant compounds such as those described in "The Chemistry o~ the 5 Quinoid Compounds" Parts I and II (~ondon, Wiley 1974, Publishers: Patai) frequently manufactured e.g. as dyes or dye precursors. ~ny quinoid compound is in principle suitable for use as catalyst component (ii) i~ it is capable of oxldizing the noble metal present in ca-talyst 10 component (i) from the ~ero oxidation state to a positive oxidation state under the reaetion conditions o~ the pre-sent invention. Preferred quinoid compounds are those which are eapable of converting palladium (a particularly pre~erred metal) from zero oxidation state to its ~2 oxi-15 dation state.
Instead of such quinoid eompounds, compounds capableo~ being converted into sueh quinoid compounds may be used as catalyst component (ii). That is, eompounds whieh are converted into sueh a quinoid eompound by an 20 oxidation reaction (brought about by the oxidizing agent ~sed in the process of the present invention), or by solvolysis or an elimination reaction may be used as eatalyst component (ii).
Suitable quinoid catalyst components (ii) include:
25 ortho- and para-quinones; multinuclear quinones; and heterocyclic quinones in a substituted or unsubs-titu-ted form; imino, N-al~yl- or ~-arylimino deri~atives of these quinones,e.~. o-tetrachlorobenzoquinone/ p-tetrachloro-benzoquinone, 2,5~dichloro-3,6-dihydroxy-p-benzoquinone, 30 2-chlorophenyl-1,4-benzoquinone, 2,3-dichloronaphthoqui-none, anthraquinone, l-chloroanthraquinone, 7-chlo~ro-4-hydroxy 1,10 anthraquinone, 1-nitroanthraquinone~2-carboxylic acid, 1,5-dichloroanthra~uinone, 1,8-dichloro-anthraquinone, 2,6-dichloroanthraquinone, 1,4-dihydroxy-35 anthraquinone, acenaphthenedione, 5,7-dichloro-lH-indol-Mo-2379 5'7~3 2,3-dlone, indi~o or 1,4-dihydro-2,3-quinoxalinedione.
Polymeric quinoid compounds such as those described by H.G. Cassidy and R.~. Kun in "Oxida~ion-P~eductio~ Poly-mers" (Polymer Reviews Vol~ 11, Interscience Publ. New 5 York 1965) are also suitable as catalyst component (li).
Preferred quinoid compounds are those which are substituted with one or more electron-accepting substituent such as chlorine, bromine, cyano-, nitro-, carboxylic acid or sulfonic acid groups because such substituents increase 10 the capacity fQr oxidation. Quinoid comPounds containing N-aryl or N-alkyl substituents are also particularly effective. Examples of particularly preferred quinoid compounds include: o-tetrachlorobenzoquinone, p-tetra-chlorobenzoquinone, 2,5-dichloro-3,6-dihydroxy-p-benzo-15 quinone, 2,3-dichloro-1,4-naphthoquinone, 7-chloro-4-hydroxy-1,10-anthraquinone, 1,5~dichloroanthraquinone, 1,8-dichloroanthraquinone and 2-(N-phenylamino)-3-chloro-1,4-naphthoquinone.
Quinoid precursors which are suitable as catalyst 20 component (ii) include ketals of the above-described corresponding quinoid catalyst components and hydrogenated forms of these quinoid components (particularly the corre-sponding hydroquinones). Aromatic amines and polynuclear aromatic compounds substituted e.g. by sulfonic acid, car-25 boxylic acid, nitro or cyano ~roups or such materialswhich already contain a keto group in the ring system are also converted into quinoid catalyst components (ii) under the oxidizing reaction conditions.
Suitable precursors of quinoid catalyst components 30 (ii) include the hydroquinones and ketals of the above-mentioned quinones, 5-amino-2~(phenylamino)-benzene sul-fonic acid, 5-amino-2-[(4-chlorophenyl)amino]-benzene sulfonic acid, 4,4'-diamino-(1,1' biphenyl)-3,3'-disul-fonic acid, 2-aminobenzene sulfonic acld and benzanthrone-Mo-2379 -~c~s~
wherein Rl, R , R3 and R4 represent alkyl or aryl groups~
15 When molecular oxygen is used as the oxidizing agent, the reaction takes place in accordance with the following equation (Z):
o Equation (2) R -NH-C-NH-R + 2 R -OH + CO ~ 1/2 2 , Rl-NH-C-oR4 + R2-NH-C-oR4 + H20 From these equations it is readily seen that one disad-vantage of usiny nitro compounds as oxidizing agents is the formation of a mixture of urethanes which must be 25 separated (e.g. by distil]ation). ~litro compounds are therefore useful oxidizing agents only when substituen-ts Rl, R2 ~ R3 are identical because only then will the formation of a mixture of urethanes be avoided. It is rare, however, that both, the appropriate urea compound 30 and the nitro compound which corresponds to this urea compond are simultaneously available for the reaction on a large commercial scale.
Mo-2379 Aside from the nature of the oxidlzin~ agent, another disadvantage of the process disclosed in German Offenle--gungsschrift ~lo. 2,980,25~ lies in the ract that rela~
tively large quantities of inorganic or organic halides 5 must be used as cocatalysts. These halides are hiqhlv corrosive. They also impair the process when carried out on a commercial scale because they are largely insoluble in the reaction environment.
SUMMA:RY OF THE INVE~TION
It is an ohject of the present invention to provide ;an imprcved p-~ocess for the production of urethanes.
It is another object of the present invention to provide a process for the production of urethanes in which very little, if any, insoluble and corrosive catalyst 15 is required.
These and other objects which will ~e apparent to those skilled in the art are accompllshed by reacting a urea having at least one hydrogen atom bonded to a urea nitrogen atom, an organic compound containing at least 20 one hydroxyl group and carbon mono~ide in the presence of molecular oxy~en and a catalyst system. The catalyst system is made up of (i) a noble metal and/or a comPound of a noble metal and (ii) at least one quinoid compound having an oxidizing effect on the reactants resp.on oxi-dizable catalyst components and/or atleast one compound capable of being converted into an oxidizing quinoid compound under reaction conditions. The catalyst system may also include tertiarv amines and/or magnesium compounds and/or compounds of elements from groups III A to V A and I }3 to VIII B of the Periodic System of Elements. The reaction is generally carried out at a temperature of from 100 to 300C and a pressure from 5 to 500 bar.
Mo-2379 S'7~
DETAILED DESCRIPTION OF THE INVEN~ION
~ he present invention relates ~o a process for the preparation of urethanes by reactinq an unsubstituted or substituted urea containin~ at least one hydrogen atom 5 attached to a urea ni-trogen atom with an organic compound containing at least one hydroxyl group and carbon monoxi.de in the presence of molecular oxygen and a catalyst system.
The catalyst syste~ is made up of (i) at least one noble metal and~or a compound of a noble metal of the Eighth 10 Sub-group of the Periodic System of Elements, and (ii) at least one quinoid compound having an oxidizing action and/or at least one compound capable of being converted into an oxidizing quinoid compound under the reaction conditions~
Suitable ureas are any organic compounds having at least one structural unit of the formula H - N - CO - N -in which the free valencies are saturated by hydrogen a-toms or by organic substituents whieh are preferably 20 inert under the reaction conditions. Examples oE such ureas include urea itself or substituted ureas corre sponding to the formulae (I), (II), (III):
~ ~ 5 N-C-N N---C- ,N N C-N X
25 ~1 x2 ~ X4 ~ Xl (I) (II) (III) in which Xl, X2, and X3 (which may be the same or differ-30 ent) represent hydroqen or any organie group which is inert under the reaction conditions, such as aliphatic hydrocarbon groups havinq from 1 to 4 earbon atoms or Mo-2379 aromatic hydrocar~on groups ha~ing from 6 to 10 carbon atoms. The di~alent substituent X4 and the two nitrogen atoms of the urea group together form an a-t least 5-membered heterocyclic ring having at least one (prefer-5 ably 2 to 6) carbon atoms arranged within the ring andoptionally hetero atoms additionally present in the ring.
The divalent substituent X5 forms a heterocyclic ring (preferably 5- or 6- membered) with one of the nitrogen atoms of the urea group as rlng member, and in addition 10 to at least two carbon atoms axranged within the ring i-t may ha~e other hetero atoms arranged within the ring.
All oE the substituents Xl through X may be substi-tuted or interrupted by difunctional groups. Sui-ta~le substituents or difunctional groups include halogen atoms, 15 keto groups, sulfoxide groups, sulfone g~oups, ether groups, carboxylic acld esters and nitro groups. Other urea grouPs may also be functional groups, i.e.one molecule of the starting urea may contain more than one urea group. If these additional urea groups are of the type depicted in 20 general formulae I, II, or III, they are also converted into urethane groups in accordance with the present inven-tion. If the urea starting material contains one or more amino groups, these amino groups are also converted into urethane groups under the reaction conditions described 25 in German Offenlegungsschrift No. 3,0~,982. The molecu-lar weights of suitable urea starting materials generally range from 60 to 600.
The urea compound used as the starting material is preferably a urea correspondlng to formula (I) and/or (II) 30 which is sy~metrically substituted. It is particularly preferred to use N,N'-disubstituted ureas of formula ~I) in which the two su~stituents are identical groups, particularly Cl C4-al~yl groups or a phenyl group. Unsub-stituted urea is also suitable.
Mo~2379 ~2~'7~
Specific examp].es of suitable urea s-tarting materials include: urea, N-tert.-butylurea, N,N dimethvlurea, N,N'-dimethylurea, N-phenyl-N,N'-dimethyl-urea, tris (2-chlorophenyl)-urea, 6-nitxo-1-naphthylurea, 3~amino-5 4-methyl-phenylurea, 2-imidazolidinone, 1,4-butylene-bis-urea, N,N-pentamethylene-urea, N,N'-bis-(2-furyl)-urea, l-oxa-6,8-diazacyclododecanone-7, and N,N'-2,2'-bipheny-lene urea. Preferred urea star-ting materials include:
urea, N,N'-dimethylurea, N,N'-dicyclohexyl-urea, N,N'-10 diphenylurea, N,N'~bis-(p-tolyl)-urea, ~,N'-bis-(2-amino-phenyl)-urea, N,N'-bis-(4-nitrophenyl)-urea and N,N'-bis-(4-chlorophenyl)-urea. N,N'-dimethylurea and ~,N'-diphenylurea are particularly preferred.
The hydroxyl group-containing starting material may 15 be any organic compound containing hydroxyl groups, in particular a monohydric or higher hydric alcohol or a monohydric or higher hydrlc phenol. Compounds which are saturated monohydric aliphatic alcohols in the molecular weight range of from 32 to 300 containing primary hydroxyl 20 groups or monovalent phenols with a maximum molecular weight of 300 are particularly preferred.
The alcohol starting material may be any straight chained or branched monohydric or polyhydric alkanol, alkenol, cycloalkanol, cycloalkenol or aralkyl alcohol.
25 These alcohols may contain inert substituents. Suitable inert substituents include halogen atoms, sulfoxide groups, sulfone groups, nitro groups, carbonyl groups and carbox~
ylic acid ester groups. ~lcohols having ether bridges are also suitable. Specific examples of suitable alcohols are:
30 Methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, n-hexanol, cyclohexanol, benzyl alcohol, chloro-ethanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, hexanetriol and trimethylolpropane. Monohydric aliphatic alcohols having 35 from 1 to 6 carbon atoms are particularly preferred.
Mo-2379 Suitable phenols include: phenol, 2-isopropox~-phenol, 7-hydroxy-2, 2-dimethyl-2,3-dihydrobenzofuran, the isomeric chlorophenols, cresols, ethylphenols, propyl-phenols, bu~ylphenols or higher alkylphenols, pyrocate-5 chol, 4,4' dihydroxy-diphenylmethane, bisphenol-A, anthra~
nol, phenanthrol, pyroyallol, phloroglucinol or 8-quino~
linol. Preferred mononuclear phenols having up to 12 carbon atoms and dinuclear phenols having up to 18 carbon atoms are preerable.
In carrying out the process accoxding to the inven-tion, the hydroxyl group-containing starting material is generally used in a quantity such that from 2 to 200, preferably from 2 to 100 mol of hydxoxyl groups are pre-sent for each mol of urea groups of the urea star-ting 15 material present in the reaction mixture. Since relatively inexpensive hydroxyl compounds which are liquid under the reaction conditions are generally used, they are preferably used in excess within the ranges mentioned. The excess hydroxyl compound then serves as the reaction medium (solvent).
Carbon monoxide is also used as a reactant in the process of the present invention. This starting material is generally used in a quantity such that from 0.5 to 30 mol of carbon ~onoxide is present for each mol of urea 25 group in the urea starting material. If primary amlno groups are also to be converted into urethane groups (according to German Offenlegungsschrift No. 3,046,982), at least one additional mol of carbon monoxide must be provided for each mol of amino group to be reacted.
The oxidizing agent used in the present invention may be molecular oxygen in the pure form or in the form of a mixture with an inert gas such as nitrogen, carbon dioxide, or preferably aix. In the presence of molecular oxygen, oxycarbonylation takes place (i.e., the reaction 35 proceeds as shown in equation (2)) or, in the case of Mo-2379 ~a~s~7~
symmetrically su~stltuted urea starting materials, the reaction may proceed in the manner shown in equation (3):
H ~ H
Equation (3) R -N-C-N-Rl + 2 R4-oH ~ CO + l2 2 H O
2 R -N-C-oR4 + H2O
It ls readily seen from this equatlon, that 1/2 mol of carbon monoxide and l/4 mol of molecular oxygen are re-quired ror each urethane group formed in tha described 10 reaction. Molecular oxygen is generally used in a quantity ranging from approximately stoichiometric to approximately 5 times the stoichiometric amount (based on the urea groups to be reacted). If the hydroxyl group containing starting material used is sensltive to ox~di-15 zing agen-ts, it is often advisable to use the oxy~en oxidizing agent in less than the equivalen~ quantity, (based on the urea groups of the urea starting material).
It may therefore be appropriate to use oxygen in a quan-tity which is only 60 to 100% of the equivalent quantity 20 when hydroxyl group-containing starting materials which are sensitive to oxidation are used. In such cases where less than a stoichiometric quantity of oxygen is used, the loss in yield due to use of such a lesser amount is much smaller than the loss due to formation of unwanted 25 oxidation productsO Moreover, when subequivalent quan-tities of oxygen are used,unreacted starting materlals may be easily recovered and used again whereas alcohol destroyed by unwanted oxidation reactions cannot be recovered.
The oxidizing agent employed in the present invention may in principle be any inorganic, largely ionic compound which has an oxidizing action, particularly salt-type compounds of metals in higher valency stages. Organic Mo-2379 .
oxidizing agents, in particular quinones, are also suitable in principle. All of these oxidizing agents are, however, less suitable than oxygen. Organic nitro compounds are no-t suitable oxidizing agents in the process of the 5present in-~ention.
The process of the present invention must be carried out in the presence of a catalyst sys-tem. This catalyst system is made up of (i) at least one noble metal and/or at least one compound of a noble metal of the Eighth lOSub-group of ~he Periodic System of Elements and (ii) at least one quinoid compound having an oxidizing action and/or at least one compound capable of being convertecl into an oxidizing quinoid compound under the reaction conditions.
Catalyst component (i) may be either a noble metal of the Eighth Sub-group of the Periodic Sys~em or a som-pound of such a metal. It is particularly advantageous to use a noble metal compound which is soluble in the reac-tion mixture, such as a chloride, bromide, iodide, 20chlorine complex, bromine complex~ iodine complex, ace-tate, acetyl acetonates or other soluble noble metal compounds. Preferred noble metals are palladium, ruthen-ium and rhodium. Palladium is particularly preferred, especially in the form of soluble palladium chloride or 25 palladium acetate.
Preferred concentrations for catalyst co~ponent (i) are generally from 3 to 1000 ppm (preferably from 5 to 100 ppm), calculated as noble metal and based on the whole reaction mixture, including any solvent used.
30 Although higher concentrations o noble metal could be used, such concentrations are uneconomical due to possible loss of noble metal, particularly since they do not increase the yield o urethane.
Catalyst component (ii) is a quinoid compound Mo-2379 q ~
havlng an oxidi~ing action and/or a compound capable of being con~erte.d into an oxidizing quinoid compound un~er the reaction conditions. By "quinoid co~pounds" are ~eant compounds such as those described in "The Chemistry o~ the 5 Quinoid Compounds" Parts I and II (~ondon, Wiley 1974, Publishers: Patai) frequently manufactured e.g. as dyes or dye precursors. ~ny quinoid compound is in principle suitable for use as catalyst component (ii) i~ it is capable of oxldizing the noble metal present in ca-talyst 10 component (i) from the ~ero oxidation state to a positive oxidation state under the reaetion conditions o~ the pre-sent invention. Preferred quinoid compounds are those which are eapable of converting palladium (a particularly pre~erred metal) from zero oxidation state to its ~2 oxi-15 dation state.
Instead of such quinoid eompounds, compounds capableo~ being converted into sueh quinoid compounds may be used as catalyst component (ii). That is, eompounds whieh are converted into sueh a quinoid eompound by an 20 oxidation reaction (brought about by the oxidizing agent ~sed in the process of the present invention), or by solvolysis or an elimination reaction may be used as eatalyst component (ii).
Suitable quinoid catalyst components (ii) include:
25 ortho- and para-quinones; multinuclear quinones; and heterocyclic quinones in a substituted or unsubs-titu-ted form; imino, N-al~yl- or ~-arylimino deri~atives of these quinones,e.~. o-tetrachlorobenzoquinone/ p-tetrachloro-benzoquinone, 2,5~dichloro-3,6-dihydroxy-p-benzoquinone, 30 2-chlorophenyl-1,4-benzoquinone, 2,3-dichloronaphthoqui-none, anthraquinone, l-chloroanthraquinone, 7-chlo~ro-4-hydroxy 1,10 anthraquinone, 1-nitroanthraquinone~2-carboxylic acid, 1,5-dichloroanthra~uinone, 1,8-dichloro-anthraquinone, 2,6-dichloroanthraquinone, 1,4-dihydroxy-35 anthraquinone, acenaphthenedione, 5,7-dichloro-lH-indol-Mo-2379 5'7~3 2,3-dlone, indi~o or 1,4-dihydro-2,3-quinoxalinedione.
Polymeric quinoid compounds such as those described by H.G. Cassidy and R.~. Kun in "Oxida~ion-P~eductio~ Poly-mers" (Polymer Reviews Vol~ 11, Interscience Publ. New 5 York 1965) are also suitable as catalyst component (li).
Preferred quinoid compounds are those which are substituted with one or more electron-accepting substituent such as chlorine, bromine, cyano-, nitro-, carboxylic acid or sulfonic acid groups because such substituents increase 10 the capacity fQr oxidation. Quinoid comPounds containing N-aryl or N-alkyl substituents are also particularly effective. Examples of particularly preferred quinoid compounds include: o-tetrachlorobenzoquinone, p-tetra-chlorobenzoquinone, 2,5-dichloro-3,6-dihydroxy-p-benzo-15 quinone, 2,3-dichloro-1,4-naphthoquinone, 7-chloro-4-hydroxy-1,10-anthraquinone, 1,5~dichloroanthraquinone, 1,8-dichloroanthraquinone and 2-(N-phenylamino)-3-chloro-1,4-naphthoquinone.
Quinoid precursors which are suitable as catalyst 20 component (ii) include ketals of the above-described corresponding quinoid catalyst components and hydrogenated forms of these quinoid components (particularly the corre-sponding hydroquinones). Aromatic amines and polynuclear aromatic compounds substituted e.g. by sulfonic acid, car-25 boxylic acid, nitro or cyano ~roups or such materialswhich already contain a keto group in the ring system are also converted into quinoid catalyst components (ii) under the oxidizing reaction conditions.
Suitable precursors of quinoid catalyst components 30 (ii) include the hydroquinones and ketals of the above-mentioned quinones, 5-amino-2~(phenylamino)-benzene sul-fonic acid, 5-amino-2-[(4-chlorophenyl)amino]-benzene sulfonic acid, 4,4'-diamino-(1,1' biphenyl)-3,3'-disul-fonic acid, 2-aminobenzene sulfonic acld and benzanthrone-Mo-2379 -~c~s~
3-carbonitrile.
Catalyst component (ii) is ~enerally added to the reaction system at a concentration of from 0.1 wt % to 5 wt %, preferably concentrations of from 0.5 to 3 wt ~, 5 ~based on the -total quantity of reaction mixture including any solvents used). The catalyst system used in the pres-ent invention may also contain certain metal compounds and/
or tertiary amines as addi~ional components.
These optional catalyst components include magnesium 10 compounds (particularly inorganic or organic salts of magnesium) and compounds of elements of the Third to Fifth Main Group and/or First to ~ighth Sub-group of the Periodic System of Elements which are capable of under-going a redox reaction under the reaction conditions.
15 Such catalyst components are preferably compounds of metals of atomic numbers 12, 22 ko 23, 41, 47, 58 and 92 which compounds are at least partially soluble in the reaction mixture. Particularly p~eferred optional catalyst com-ponents are the acetates, nitrates and chlorides of chro-20 mium, manganese, cobalt, copper, cerium and magnesium~optionally in the form o-f hydrates or amine complexes of these metal salts. Oxides of the metals enumerated above may also be used as catalyst components in combination with activating chlorides, e.g. ammonium chlorides. If 25 these catalyst components are used, they are generally added in 1 to 10 times the molar quantity (based on cata~
lyst component (i)). The catalyst component may be used in a quantity of up to 0.1 wt ~ (based on the total weight of the reaction mixture including any solvents 30 used).
When present in the catalyst system, -tertiary amine catalyst components act as complex formers for the oxidized form of catalyst component (i) and for any optional catalyst component of the type described above Mo-2379 5'~
if -the complex forming action of the starting compounds present in the reaction mixture is not sufficient for these purposes. Any tertiary amines, i.e. amines which contain aliphatically, cycloali.phatically, araliphaticalïy 5 and/or aromatically bound tertiary amino groups or tertiary amino groups which form part of a heterocyclic ring are appropriate to the present invention. Examples of suitable tertiary amines include triethylamine, diisopropylmethylamine, cyclohexyldiethylamine, triphenyl~
10 amine, N,N-diethyl-aniline, N-phenyl-piperidine, pyri-dine, quinoline, 1,4-diaza-(2,2,2)-bicyclooctane and pyrimidine. Triethylamine, N,N-diethyl-aniline and pyridine are preferred -tertiary amine catalyst components.
The above mentioned tertiary amines may also be used as 15 metal salt complexes of catalyst component (i) and some of the optio~ally used catalyst components. I catalyst component (i) and/or an optional catalyst component is used in an oxidic form, it is generally advantageous to actlvate it by using the tertiary amines in the form of 20 hydrochlorides. The op-tional tertiary amine catalyst component is generally used in a quantity of up to 10 wt %, preferably from 0.2 to 3 wt % (based on the total reaction mixture including any solvents used) bu~ larger quantities may be employed.
The process of the present invention may be carried out in the presence or absence of solvents. The hydroxyl group-containing starting material which is preferably used in excess may act as solvent but inert solvents may also be used. Such inert solvents may constitute up to 30 80 wt % of the whole reaction mixture. The quantity of solvent used, whether it be excess hydroxyl compound or an inert solvent, must be calculated so that the heat of the exothermic reaction of urethane formation can be dissipated without greatly increasing the temperature.
Mo-2379 5~
The process of the present invention is therefore generally carried out uslng a concentration of urea startiny material of from 5 to 30 wt %, preferably from 5 to 20 wt ~ (based on the whole reactlon mixture including the 5 solvent).
Suitable solvents are those which are inert ~ith respect to the reactants and the catalyst system such as aromatic, cycloaliphatic and aliphatic hydrocarbons, optionally su~stituted with halogens. Specific examples 10 of such solvents are benzene, toluene, xylene, chloro-benzene, dichlorobenzene, trichloroberzene, chloronaph-thalene, cyclohexane, methylcyclohexane, chlorocyclohexane, methylene chlori~e, carbon tetrachloride, tetrachloro ethane, trichlorotrifluoroethane and similar compounds 15 as well as tertiary amines.
The reaction temperature in -the process of the present invention is generally from 100 to about 300C, preferably from 100 to 250C and most preferably from 140 to 220C. The pressure which ~ould be adjusted to ensure 20 that a liquid phase is always present, is ~enerally from 5 to 500 bar, preferably from 30 to 300 bar. The reaction time required for quantitative conversion varies from a few minutes to several hours, depending upon the starting materials employed.
The process of the present invention may be carried out batchwise or continuously. It is advantageous to select a solvent in which the produc-t of the process (urethane) is easily soluble. After release of the pres-sure from the reaction medium and cooling to a temperature 30 in the region of 50C to 80C, catalyst components (i), (ii) and optional metal catalysts (including in some cases the complex form of tertiary amine catalysts) pre-cipitate substantially completely in many solvents.
In some cases, it is advantageous to concen-trate the reac-35 tion mixture by evaporation -to 70-50% of the ori~Jinal Mo-2379 ~2~
volume in order to precipi-tate the catalyst. The catalyst mixture may then be separated from the solution containing urethane by filtration or centrifuging. If precipita-tion of the catalyst components is not possible, they mav 5 be ~ecovered as r~sidue from a process such as dlstillation.
The catalyst components separated by one of the methods mentioned above can in most cases be returned to the process and reused although they are in a chernically changed form. ~f -the catalyst component (ii) contained 10 halogen, the catalyst mixtures obtained after the reaction will have a lower halogen content. These catalysts may then contain chemically bound nitrogen as a result of reactions with the urea starting material.
Depending upon the nature o the starting materials 15 and on the reaction conditions primary amines may be li-berated by side reactions from the urea starting material or from the urethane obtained as produc-t of the process.
These primary amines together with excess hydroxyl grou~-containing material may generally be removed from the 20 product mixture by distillation and returned to the process after the addition of fresh starting rnateri.als. According to German Offenlegungsschrift No. 3,046,982, when amines formed by such side reactions are reacted with the same catalyst systems and under the same reaction conditions, 25 the urethanes which are obtained from the urea starting material by the process of the present invention are obtalned. Any losses in yield due to side reactions are thereore very slight if these by-products are returned to the reaction environment.
The urethanes obtained as products of the ~rocess of the present invention are generally the least volatile constituents of the product mixtures aside from the cata-lyst components (i), (ii) and optional metal catalysts.
After removal of the more volati]e constituents of the Mo-2379 3~'7 product solution, the product urethane may be purified or separated f~om the catalyst components either by further distillation (which should in most cases be carried out under vacuum), by extraction or crystallization. Any 5 tertiary amine catalyst used in the pro~ess is generally distilled off with the more volatile constituents or with solvent and may be returned to the reaction environment unless it is bound by complex foxmation with a metal catalyst componen-t.
The products of the process of the present invention (urethanes) are suitable or use as pesticides or as intermediate products for the preparation of pesticides.
They are also suitable as starting materials for the pre-paration of the isocyanates on which they are based.
15 These isocyanates are prepared by thermal cleavage of the urethane in accordance with techniques known to those in the art.
The process of the present invention is illustrated by the following Examples but the invention is not limited 20 to the conditions given in these Examples.
EXAMPLES
Most of the experiments described below were carrled out in an enamelled 1.3 l steel autoclave to exclude any catalytic effect from the metal of the wall~
25 Some experiments were carried out in a 0.7 1 refined steel autoclave. The urethane yields, (calcuiated on the basls of equation (2)) are based on the amount of urea used un-less otherwise indicated and are given in terms of mol ~.
The amine yields, in particular the aniline yields (when ~0 diphenylurea, which is particularly preferred, was used as the urea starting material) which are the result of side reactions, were calculated on the basis of the following, theoretical equation (4):
Mo-2379 . ~
~ t3~7 Equation (4) H ~ H
~ N-C-N ~ 2 ~ ~ NH2 + C2 5 ~his equation serves only as a basis for the calculation and in no way represents the actual mode of forma-tion of the amine or aniline.
Exam~les 1 to The procedure in each of these examples was as lO follo~s:
531.9 g of a mixture having the composition described below were introduced into an enamelled 1.3 l refined steel autoclave. The mixture was made up of 94 ppm of a noble metal chloride (see ~able 1 for the specific com-15 pound), 188 ppm of copper (II) acetate monohydra-te, 81.4 w-t ~ of ethanol, 16.9 wt ~ of N,N'~diphenylurea (DPH) and 1.6 wt % of p-tetrachlorobenzoquinone. 100 bar of carbon monoxide and 25 bar of air were then forced into the autoclave at room temperature. The reaction mixture 20 was heated to 180C with stirring and left to react at this temperature for one hour.
After the reaction mixture had cooled to room tem-perature, the pressure was released and a second, similar reaction phase ~as carried out with a fresh mix-ture of 25 carbon monoxide and air. A total of about 1.3 oxidation equivalents (based on DPH) was introduced in the form cf atmospheric oxygen. The resul-ts shown in Table l were obtained from gas chromatographic analysis. Example 6 is a comparison example carried out without catalyst 30 component (i) of the pxesent invention.
Mo-2379 57~
Table l Example Catalyst Yield ln mol %
No. component Phenyl _ _ _ _(i) urethaneAniline l PdC12 77.7 10.0 2 RuC13 72.2 12.4 3 RhCl3 63.~ 12.6
Catalyst component (ii) is ~enerally added to the reaction system at a concentration of from 0.1 wt % to 5 wt %, preferably concentrations of from 0.5 to 3 wt ~, 5 ~based on the -total quantity of reaction mixture including any solvents used). The catalyst system used in the pres-ent invention may also contain certain metal compounds and/
or tertiary amines as addi~ional components.
These optional catalyst components include magnesium 10 compounds (particularly inorganic or organic salts of magnesium) and compounds of elements of the Third to Fifth Main Group and/or First to ~ighth Sub-group of the Periodic System of Elements which are capable of under-going a redox reaction under the reaction conditions.
15 Such catalyst components are preferably compounds of metals of atomic numbers 12, 22 ko 23, 41, 47, 58 and 92 which compounds are at least partially soluble in the reaction mixture. Particularly p~eferred optional catalyst com-ponents are the acetates, nitrates and chlorides of chro-20 mium, manganese, cobalt, copper, cerium and magnesium~optionally in the form o-f hydrates or amine complexes of these metal salts. Oxides of the metals enumerated above may also be used as catalyst components in combination with activating chlorides, e.g. ammonium chlorides. If 25 these catalyst components are used, they are generally added in 1 to 10 times the molar quantity (based on cata~
lyst component (i)). The catalyst component may be used in a quantity of up to 0.1 wt ~ (based on the total weight of the reaction mixture including any solvents 30 used).
When present in the catalyst system, -tertiary amine catalyst components act as complex formers for the oxidized form of catalyst component (i) and for any optional catalyst component of the type described above Mo-2379 5'~
if -the complex forming action of the starting compounds present in the reaction mixture is not sufficient for these purposes. Any tertiary amines, i.e. amines which contain aliphatically, cycloali.phatically, araliphaticalïy 5 and/or aromatically bound tertiary amino groups or tertiary amino groups which form part of a heterocyclic ring are appropriate to the present invention. Examples of suitable tertiary amines include triethylamine, diisopropylmethylamine, cyclohexyldiethylamine, triphenyl~
10 amine, N,N-diethyl-aniline, N-phenyl-piperidine, pyri-dine, quinoline, 1,4-diaza-(2,2,2)-bicyclooctane and pyrimidine. Triethylamine, N,N-diethyl-aniline and pyridine are preferred -tertiary amine catalyst components.
The above mentioned tertiary amines may also be used as 15 metal salt complexes of catalyst component (i) and some of the optio~ally used catalyst components. I catalyst component (i) and/or an optional catalyst component is used in an oxidic form, it is generally advantageous to actlvate it by using the tertiary amines in the form of 20 hydrochlorides. The op-tional tertiary amine catalyst component is generally used in a quantity of up to 10 wt %, preferably from 0.2 to 3 wt % (based on the total reaction mixture including any solvents used) bu~ larger quantities may be employed.
The process of the present invention may be carried out in the presence or absence of solvents. The hydroxyl group-containing starting material which is preferably used in excess may act as solvent but inert solvents may also be used. Such inert solvents may constitute up to 30 80 wt % of the whole reaction mixture. The quantity of solvent used, whether it be excess hydroxyl compound or an inert solvent, must be calculated so that the heat of the exothermic reaction of urethane formation can be dissipated without greatly increasing the temperature.
Mo-2379 5~
The process of the present invention is therefore generally carried out uslng a concentration of urea startiny material of from 5 to 30 wt %, preferably from 5 to 20 wt ~ (based on the whole reactlon mixture including the 5 solvent).
Suitable solvents are those which are inert ~ith respect to the reactants and the catalyst system such as aromatic, cycloaliphatic and aliphatic hydrocarbons, optionally su~stituted with halogens. Specific examples 10 of such solvents are benzene, toluene, xylene, chloro-benzene, dichlorobenzene, trichloroberzene, chloronaph-thalene, cyclohexane, methylcyclohexane, chlorocyclohexane, methylene chlori~e, carbon tetrachloride, tetrachloro ethane, trichlorotrifluoroethane and similar compounds 15 as well as tertiary amines.
The reaction temperature in -the process of the present invention is generally from 100 to about 300C, preferably from 100 to 250C and most preferably from 140 to 220C. The pressure which ~ould be adjusted to ensure 20 that a liquid phase is always present, is ~enerally from 5 to 500 bar, preferably from 30 to 300 bar. The reaction time required for quantitative conversion varies from a few minutes to several hours, depending upon the starting materials employed.
The process of the present invention may be carried out batchwise or continuously. It is advantageous to select a solvent in which the produc-t of the process (urethane) is easily soluble. After release of the pres-sure from the reaction medium and cooling to a temperature 30 in the region of 50C to 80C, catalyst components (i), (ii) and optional metal catalysts (including in some cases the complex form of tertiary amine catalysts) pre-cipitate substantially completely in many solvents.
In some cases, it is advantageous to concen-trate the reac-35 tion mixture by evaporation -to 70-50% of the ori~Jinal Mo-2379 ~2~
volume in order to precipi-tate the catalyst. The catalyst mixture may then be separated from the solution containing urethane by filtration or centrifuging. If precipita-tion of the catalyst components is not possible, they mav 5 be ~ecovered as r~sidue from a process such as dlstillation.
The catalyst components separated by one of the methods mentioned above can in most cases be returned to the process and reused although they are in a chernically changed form. ~f -the catalyst component (ii) contained 10 halogen, the catalyst mixtures obtained after the reaction will have a lower halogen content. These catalysts may then contain chemically bound nitrogen as a result of reactions with the urea starting material.
Depending upon the nature o the starting materials 15 and on the reaction conditions primary amines may be li-berated by side reactions from the urea starting material or from the urethane obtained as produc-t of the process.
These primary amines together with excess hydroxyl grou~-containing material may generally be removed from the 20 product mixture by distillation and returned to the process after the addition of fresh starting rnateri.als. According to German Offenlegungsschrift No. 3,046,982, when amines formed by such side reactions are reacted with the same catalyst systems and under the same reaction conditions, 25 the urethanes which are obtained from the urea starting material by the process of the present invention are obtalned. Any losses in yield due to side reactions are thereore very slight if these by-products are returned to the reaction environment.
The urethanes obtained as products of the ~rocess of the present invention are generally the least volatile constituents of the product mixtures aside from the cata-lyst components (i), (ii) and optional metal catalysts.
After removal of the more volati]e constituents of the Mo-2379 3~'7 product solution, the product urethane may be purified or separated f~om the catalyst components either by further distillation (which should in most cases be carried out under vacuum), by extraction or crystallization. Any 5 tertiary amine catalyst used in the pro~ess is generally distilled off with the more volatile constituents or with solvent and may be returned to the reaction environment unless it is bound by complex foxmation with a metal catalyst componen-t.
The products of the process of the present invention (urethanes) are suitable or use as pesticides or as intermediate products for the preparation of pesticides.
They are also suitable as starting materials for the pre-paration of the isocyanates on which they are based.
15 These isocyanates are prepared by thermal cleavage of the urethane in accordance with techniques known to those in the art.
The process of the present invention is illustrated by the following Examples but the invention is not limited 20 to the conditions given in these Examples.
EXAMPLES
Most of the experiments described below were carrled out in an enamelled 1.3 l steel autoclave to exclude any catalytic effect from the metal of the wall~
25 Some experiments were carried out in a 0.7 1 refined steel autoclave. The urethane yields, (calcuiated on the basls of equation (2)) are based on the amount of urea used un-less otherwise indicated and are given in terms of mol ~.
The amine yields, in particular the aniline yields (when ~0 diphenylurea, which is particularly preferred, was used as the urea starting material) which are the result of side reactions, were calculated on the basis of the following, theoretical equation (4):
Mo-2379 . ~
~ t3~7 Equation (4) H ~ H
~ N-C-N ~ 2 ~ ~ NH2 + C2 5 ~his equation serves only as a basis for the calculation and in no way represents the actual mode of forma-tion of the amine or aniline.
Exam~les 1 to The procedure in each of these examples was as lO follo~s:
531.9 g of a mixture having the composition described below were introduced into an enamelled 1.3 l refined steel autoclave. The mixture was made up of 94 ppm of a noble metal chloride (see ~able 1 for the specific com-15 pound), 188 ppm of copper (II) acetate monohydra-te, 81.4 w-t ~ of ethanol, 16.9 wt ~ of N,N'~diphenylurea (DPH) and 1.6 wt % of p-tetrachlorobenzoquinone. 100 bar of carbon monoxide and 25 bar of air were then forced into the autoclave at room temperature. The reaction mixture 20 was heated to 180C with stirring and left to react at this temperature for one hour.
After the reaction mixture had cooled to room tem-perature, the pressure was released and a second, similar reaction phase ~as carried out with a fresh mix-ture of 25 carbon monoxide and air. A total of about 1.3 oxidation equivalents (based on DPH) was introduced in the form cf atmospheric oxygen. The resul-ts shown in Table l were obtained from gas chromatographic analysis. Example 6 is a comparison example carried out without catalyst 30 component (i) of the pxesent invention.
Mo-2379 57~
Table l Example Catalyst Yield ln mol %
No. component Phenyl _ _ _ _(i) urethaneAniline l PdC12 77.7 10.0 2 RuC13 72.2 12.4 3 RhCl3 63.~ 12.6
4 IrCl3 56.5 17.2 PtC12 54~9 44.0 6 -- 48.2 47.0 .
Example 7 (Comparison example) The procedure was the same as that used in Examples 1 to 5 with the exception tha~ the catalyst system of the lS present invention was omitted. 523 g of a mixture of 82.8 wt % of ethanol and 17.2 wt % of DPH were used.
49.8 mol % of phenylurethane and 48.2 mol % of aniline were obtained.
Examples 8 to 16 __ _ The procedure used ~as that descxibed in Example 1.
532 g of a mixture of the following composition: 81.~
wt % of ethanol, 16.9 wt % of DPH, 38 ppm of palladium acetate, 188 ppm of copper (II) acetate monohydrate and 1~6 wt % of a compound corresponding to catalyst compo-25 nent (ii) were introduced into the autoclave and reacted.In Examples ~ to ll, catalyst component (ii) was a qui-noid compound; in Examples 12 to 16 the catalyst compo-nent was the precursor of a quinoid compound. The resul-ts oE these reactions are given in Table 2.
Mo-2379 Unable to recognize this page.
Example 7 (Comparison example) The procedure was the same as that used in Examples 1 to 5 with the exception tha~ the catalyst system of the lS present invention was omitted. 523 g of a mixture of 82.8 wt % of ethanol and 17.2 wt % of DPH were used.
49.8 mol % of phenylurethane and 48.2 mol % of aniline were obtained.
Examples 8 to 16 __ _ The procedure used ~as that descxibed in Example 1.
532 g of a mixture of the following composition: 81.~
wt % of ethanol, 16.9 wt % of DPH, 38 ppm of palladium acetate, 188 ppm of copper (II) acetate monohydrate and 1~6 wt % of a compound corresponding to catalyst compo-25 nent (ii) were introduced into the autoclave and reacted.In Examples ~ to ll, catalyst component (ii) was a qui-noid compound; in Examples 12 to 16 the catalyst compo-nent was the precursor of a quinoid compound. The resul-ts oE these reactions are given in Table 2.
Mo-2379 Unable to recognize this page.
5~q~
-2~-EXample 17 (Comparison example) The procedure was the same as that used in Example 8 with the exception that the copper (II) acetate mono-hydrate and qulnoid were omitted. 40.3 mol % of phenyl 5 urethane and 10.6 mol % of aniline were produced.
Example 18 The procedure was the same as was used in Example 9 bu-t without the addition of copper (II) acetate mono-hydrate. 64.8 mol % of phenyl urethane and 18.8 mol % of lO aniline were produced. Compared with Example 9, this Example shows that although the copper catalyst component is not essential to this inven-ti.on, i-t may improve the yield.
Mo-2379 Example 19 (Comparison Example) The procedure was the same as that used in Example 8 except that the mlxture was reacted under 125 bar of nitrogen for l hour at each stage rather under a carbon monoxide/air mixture. 40 mol % of phenylurethane and 52 mol % of aniline were o~tained.
Example 20 286.5 g of a mixture of the following composition were introduced into a 0.7 1 refined steel autoclave:
37.6 wt % of ethanol, 43.8 wt %6 of o-dichIorobenzene, 16.9 wt % of DPH, 1.6 wt % of 2,3-dichloro-1,4-naphtho-quinone, l90 ppm of copper (II) acetate monohydrate and 38 ppm of palladium ace~ate. A gas mixture of 100 bar of C~ and 25 bar of air was forced into the autoclave (i.e. about 0.86 oxidation equivalents ba~ed on DPH were introduced in the form of atmospheric oxygen). The reaction mixture was reacted for one hour at 180~C with stirring. 73 mol % of phenylurethane and 24 mol % of aniline were obtained~ The phenylurethane yield based on oxygen was about 85 mol -6.
Example 21 286.S g of a mixture of 81.5 wt % of methanol, 16.9 wt 6 of DPH, 1.6 wt % of 2,3-dichloro-1,4-naph~
thoquinone, 190 ppm of copper (II) acetate monohvdrate and 38 ppm of palladium acetate were reacted in the same manner as in Example 20. 66 mol g6 of O-methyl-N-phenyl-urethane and 18 mol % of aniline were obtained. The urethane ~ield based on oxygen was about 100 mol 6.
Example 22 263.7 g of a mixture having the following composi-tlon were introduced into a 0.7 1 refined steel autoclave:
88.5 wt % of phenol, 8.8 wt g6 of N,N'-dimethylurea (DMH), 2~7 wt 6 of p-tetrachlorobenzoquinone, 180 ppm of copper acetate monohydrate and 18 ppm of palladium Mo - 2379 ~13;~5"7~
acetate. The mixture was reacted for two ona-hour inter-vals at 180~C with a gas mixture of 100 bar oE carbon monoxide and 25 bar of air wlth stirring. 33.5 mol % of N methyl-O-phenylurethane was obtained.
S ExamPle 23 (Comparison Example) This Example shows that in comparison with Example 22, a reaction carried out in the absence of air as oxidizing agent, although possible, results in a sub-stantially lower urethane yield. The procedure was the same as -~hat in Example 22 but 125 bar of nitrogen were forced inio the autoclave instead of the CO/air mixture.
8 mol % of urethane was obtained.
Example 24 284 g of a mixture having the following composltion were introduced into a 0.7 1 refined steel autoclaveo 73.8 wt % of o-dlchlorobenzene, 8.2 wt % of DMH, 16.4 wt %
of 2-propanol, 1.6 wt % of p~tetrachlorobenzoquinone, 164 ppm of copper (II) acetate mono~ydrate and 41 ppm of palladium acetate. A gas mixture of 100 bar of CO and 25 har of air was forced into the autoclave (i.e. about 0.65 oxidation equivalents based on DMH was introduced in the form of atmospheric oxygen). 26 mol % of N-methyl-carbamic acid isopro~yl ester was obtained. The yield based on oxygen was about 40 mol %.
Example 25 220 g of a mixture having the following composition were introduced into a 0.7 1 refined steel autoclave~
91.1 wt % of ethanol, 6.8 wt ~ of urea, 2.1 wt % of 2,3-dichloro-1,4-naphthoquinone, 250 ppm of copper (II) acetate monohydrate and 50 ppm of palladium acetate.
The reaction was carried out in the manner described in Example 1. 42 mol % of ethylcarbamate was obtained.
Example 26 220 g of a mixture having the following composi-tion were introduced into a 0.7 1 refined steel autoclave:
Mo-2379 87.3 wt % of ethanol, 10.7 wt ~ of N,N,N'-trimethylurea, 2.0 wt % of 2,3-dlchloro-1,4-naph-thoquinone, 240 ppm of copper (II) acetate monohydrate and 48 ppm of palladium acetate. The reaction was carried out in the manner indicated in Example 1. 30 mol ~ of N-methyl-carbamic acid ethyl ester and 34 mol. % of N,N-dimethyl-carbamic acid ethyl ester were obtained. Approxima-tely 60 mol % of the N,N,N'-trimethylurea remained unreacted.
Mo-2379
-2~-EXample 17 (Comparison example) The procedure was the same as that used in Example 8 with the exception that the copper (II) acetate mono-hydrate and qulnoid were omitted. 40.3 mol % of phenyl 5 urethane and 10.6 mol % of aniline were produced.
Example 18 The procedure was the same as was used in Example 9 bu-t without the addition of copper (II) acetate mono-hydrate. 64.8 mol % of phenyl urethane and 18.8 mol % of lO aniline were produced. Compared with Example 9, this Example shows that although the copper catalyst component is not essential to this inven-ti.on, i-t may improve the yield.
Mo-2379 Example 19 (Comparison Example) The procedure was the same as that used in Example 8 except that the mlxture was reacted under 125 bar of nitrogen for l hour at each stage rather under a carbon monoxide/air mixture. 40 mol % of phenylurethane and 52 mol % of aniline were o~tained.
Example 20 286.5 g of a mixture of the following composition were introduced into a 0.7 1 refined steel autoclave:
37.6 wt % of ethanol, 43.8 wt %6 of o-dichIorobenzene, 16.9 wt % of DPH, 1.6 wt % of 2,3-dichloro-1,4-naphtho-quinone, l90 ppm of copper (II) acetate monohydrate and 38 ppm of palladium ace~ate. A gas mixture of 100 bar of C~ and 25 bar of air was forced into the autoclave (i.e. about 0.86 oxidation equivalents ba~ed on DPH were introduced in the form of atmospheric oxygen). The reaction mixture was reacted for one hour at 180~C with stirring. 73 mol % of phenylurethane and 24 mol % of aniline were obtained~ The phenylurethane yield based on oxygen was about 85 mol -6.
Example 21 286.S g of a mixture of 81.5 wt % of methanol, 16.9 wt 6 of DPH, 1.6 wt % of 2,3-dichloro-1,4-naph~
thoquinone, 190 ppm of copper (II) acetate monohvdrate and 38 ppm of palladium acetate were reacted in the same manner as in Example 20. 66 mol g6 of O-methyl-N-phenyl-urethane and 18 mol % of aniline were obtained. The urethane ~ield based on oxygen was about 100 mol 6.
Example 22 263.7 g of a mixture having the following composi-tlon were introduced into a 0.7 1 refined steel autoclave:
88.5 wt % of phenol, 8.8 wt g6 of N,N'-dimethylurea (DMH), 2~7 wt 6 of p-tetrachlorobenzoquinone, 180 ppm of copper acetate monohydrate and 18 ppm of palladium Mo - 2379 ~13;~5"7~
acetate. The mixture was reacted for two ona-hour inter-vals at 180~C with a gas mixture of 100 bar oE carbon monoxide and 25 bar of air wlth stirring. 33.5 mol % of N methyl-O-phenylurethane was obtained.
S ExamPle 23 (Comparison Example) This Example shows that in comparison with Example 22, a reaction carried out in the absence of air as oxidizing agent, although possible, results in a sub-stantially lower urethane yield. The procedure was the same as -~hat in Example 22 but 125 bar of nitrogen were forced inio the autoclave instead of the CO/air mixture.
8 mol % of urethane was obtained.
Example 24 284 g of a mixture having the following composltion were introduced into a 0.7 1 refined steel autoclaveo 73.8 wt % of o-dlchlorobenzene, 8.2 wt % of DMH, 16.4 wt %
of 2-propanol, 1.6 wt % of p~tetrachlorobenzoquinone, 164 ppm of copper (II) acetate mono~ydrate and 41 ppm of palladium acetate. A gas mixture of 100 bar of CO and 25 har of air was forced into the autoclave (i.e. about 0.65 oxidation equivalents based on DMH was introduced in the form of atmospheric oxygen). 26 mol % of N-methyl-carbamic acid isopro~yl ester was obtained. The yield based on oxygen was about 40 mol %.
Example 25 220 g of a mixture having the following composition were introduced into a 0.7 1 refined steel autoclave~
91.1 wt % of ethanol, 6.8 wt ~ of urea, 2.1 wt % of 2,3-dichloro-1,4-naphthoquinone, 250 ppm of copper (II) acetate monohydrate and 50 ppm of palladium acetate.
The reaction was carried out in the manner described in Example 1. 42 mol % of ethylcarbamate was obtained.
Example 26 220 g of a mixture having the following composi-tion were introduced into a 0.7 1 refined steel autoclave:
Mo-2379 87.3 wt % of ethanol, 10.7 wt ~ of N,N,N'-trimethylurea, 2.0 wt % of 2,3-dlchloro-1,4-naph-thoquinone, 240 ppm of copper (II) acetate monohydrate and 48 ppm of palladium acetate. The reaction was carried out in the manner indicated in Example 1. 30 mol ~ of N-methyl-carbamic acid ethyl ester and 34 mol. % of N,N-dimethyl-carbamic acid ethyl ester were obtained. Approxima-tely 60 mol % of the N,N,N'-trimethylurea remained unreacted.
Mo-2379
Claims (10)
1. A process for the production of urethanes by reacting (a) a urea having at least one hydrogen atom bonded to a urea nitrogen atom, (b) an organic compound containing at least one hydroxyl group, and (c) carbon monoxide in the presence of (d) molecular oxygen, and (e) a catalyst system comprising (i) a material selected from the group consisting of noble metals, compounds of a noble metal and mixtures thereof, and (ii) at least one oxidizing quinoid compound and/or at least one compound capable of being converted into an oxidizing quinoid compound under reaction conditions.
2. The process of Claim 1 wherein the urea is N,N'-dimethylurea or N,N'-diphenylurea,
3. The process of Claim 1 wherein the catalyst system further includes a magnesium compound or a compound capable of undergoing a redox reaction under reaction conditions selected from the group consisting of compounds of elements of the Third to Fifth Main Group, compounds of elements of the First to Eighth Sub-group of the Perio-dic System of Elements and mixtures thereof.
4. The process of Claim 1 wherein the catalyst system further comprises a tertiary amine.
5. The process of Claim 1 wherein from 5 to 100 ppm (calculated as noble metal) of the noble metal cata-lyst component (i) are employed.
6. The process of Claim 1 wherein from 0.1 to 5 wt % (based on total weight of reaction mixture) of catalyst component (ii) is employed.
7. The process of Claim 1 wherein the catalyst sys-tem further comprises up to 0.1 wt % magnesium compound and/or up to 0.1 wt % of a compound of an element of the groups IIIA to VA and/or IB to VIIIB of the Periodic System of Elements which is capable of undergoing a redox reaction under reaction conditions and/or up to 10 wt % tertiary amine.
8. The process of Claim 1 wherein the reaction is carried out at a temperature from 100 to 250°C and a pressure from 5 to 500 bar.
9. The process of Claim 1 wherein the reaction is carried out in the presence of up to 80 wt % (based on total weight of reaction mixture) of an inert solvent.
10. The process of Claim 1 wherein the catalyst system is recovered from the reaction mixture and reused.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3130843.0 | 1981-08-04 | ||
| DE19813130843 DE3130843A1 (en) | 1981-08-04 | 1981-08-04 | METHOD FOR PRODUCING URETHANES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1192570A true CA1192570A (en) | 1985-08-27 |
Family
ID=6138568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000407331A Expired CA1192570A (en) | 1981-08-04 | 1982-07-15 | Process for the preparation of urethanes |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0071835B1 (en) |
| JP (1) | JPS5841856A (en) |
| BR (1) | BR8204565A (en) |
| CA (1) | CA1192570A (en) |
| DE (2) | DE3130843A1 (en) |
| ES (1) | ES514698A0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4806674A (en) * | 1985-02-20 | 1989-02-21 | E. I. Du Pont De Nemours And Company | Preparation of urethanes by oxidative carbonylation of amines using copper carboxylates as oxidants |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8604881D0 (en) * | 1986-02-27 | 1986-04-03 | Grace W R & Co | Container caps |
| US4876379A (en) * | 1987-09-21 | 1989-10-24 | Amoco Corporation | Oxidative alkoxycarbonylation of amines and amine derivatives |
| FR2638351A1 (en) * | 1988-11-02 | 1990-05-04 | Jose Adrey | FEMORAL HIP PROSTHESIS |
| US5130464A (en) * | 1989-05-31 | 1992-07-14 | Nkk Corporation | Method of manufacturing aromatic urethanes |
| DE69030571T2 (en) * | 1990-02-13 | 1997-08-07 | Council Scient Ind Res | Process for the preparation of alkyl methyl carbamates |
| JPH0624227U (en) * | 1991-11-20 | 1994-03-29 | 東洋製罐株式会社 | Roller for transferring wickets |
| CN100349861C (en) * | 2006-06-14 | 2007-11-21 | 陈佃双 | Ethyl carbamate and its preparation method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2908251A1 (en) * | 1979-03-02 | 1980-09-11 | Bayer Ag | METHOD FOR PRODUCING URETHANES |
| DE2908252A1 (en) * | 1979-03-02 | 1980-09-11 | Bayer Ag | METHOD FOR PRODUCING URETHANES |
| US4266070A (en) * | 1979-05-25 | 1981-05-05 | Halcon Research And Development Corp. | Catalytic process for the manufacture of urethanes |
-
1981
- 1981-08-04 DE DE19813130843 patent/DE3130843A1/en not_active Withdrawn
-
1982
- 1982-07-15 CA CA000407331A patent/CA1192570A/en not_active Expired
- 1982-07-23 EP EP82106635A patent/EP0071835B1/en not_active Expired
- 1982-07-23 DE DE8282106635T patent/DE3261197D1/en not_active Expired
- 1982-08-02 JP JP57133843A patent/JPS5841856A/en active Granted
- 1982-08-03 ES ES514698A patent/ES514698A0/en active Granted
- 1982-08-03 BR BR8204565A patent/BR8204565A/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4806674A (en) * | 1985-02-20 | 1989-02-21 | E. I. Du Pont De Nemours And Company | Preparation of urethanes by oxidative carbonylation of amines using copper carboxylates as oxidants |
Also Published As
| Publication number | Publication date |
|---|---|
| ES8305705A1 (en) | 1983-05-01 |
| DE3130843A1 (en) | 1983-02-24 |
| JPH0251902B2 (en) | 1990-11-08 |
| EP0071835A1 (en) | 1983-02-16 |
| BR8204565A (en) | 1983-07-26 |
| JPS5841856A (en) | 1983-03-11 |
| ES514698A0 (en) | 1983-05-01 |
| EP0071835B1 (en) | 1984-11-07 |
| DE3261197D1 (en) | 1984-12-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3374863B2 (en) | Method for producing dialkyl carbonate | |
| US5235087A (en) | Process for the preparation of dialkyl carbonates | |
| CA1192570A (en) | Process for the preparation of urethanes | |
| GB2034691A (en) | Process for the preparation of diphenyl-methane dicarbamates and polymethylene polyphenyl carbamates | |
| EP0057321B1 (en) | Processes for substitution of aromatic organic compounds | |
| US4582923A (en) | Process for the production of urethanes | |
| US4262130A (en) | Process for the production of urethanes | |
| US4806286A (en) | Process for the preparation of acid chlorides by phosgenation of acids, and catalysts for this process | |
| US4375548A (en) | Preparation of trichloromethyl carbinols | |
| US4251667A (en) | Process for the preparation of aromatic urethanes | |
| CA1133009A (en) | Process for the preparation of urethane | |
| US4219661A (en) | Process for the production of urethanes | |
| JPS5822108B2 (en) | Method for producing aromatic diurethane | |
| JP3417418B2 (en) | Method for producing alkylene carbonate | |
| US4411820A (en) | Catalyst and process for preparing organic urethanes | |
| KR900003510B1 (en) | Preparation of urethanes by oxidative carbonylation of amines using copper carboxylates as oxidants | |
| US4976679A (en) | Process for producing a urethane and a carbonic acid ester | |
| CA1291155C (en) | Process for the preparation of carbamates | |
| US5110961A (en) | Catalytic process for the synthesis of an alcohol, new metal complexes and process for the synthesis of these complexes | |
| Smith Jr et al. | Synthesis of Isocyanatoorganosulfonyl Isocyanates and Organodisulfonyl Isocyanates1 | |
| JPH06228077A (en) | Production of urethane compound | |
| US4582929A (en) | Method of recovering halide values from carbonylation reaction mixtures | |
| JPH0678269B2 (en) | Carbonylation of olefins | |
| US4239904A (en) | Process for the preparation of urethanes | |
| JP4090526B2 (en) | Production method of dialkyl carbonate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |