JPH0320254A - Production of aliphatic o-arylurethane - Google Patents

Abstract

PURPOSE:To obtain the subject compound by reacting a carbamic acid O-aryl ester or a mixture of the compound and urea with an aliphatic primary amine as raw materials in the presence of an aromatic hydroxyl compound while eliminating ammonia as the by-product. CONSTITUTION:A carbamic acid O-aryl ester shown by formula II or a mixture of urea containing >=1wt.% carbamic acid O-aryl ester is reacted with an aliphatic primary amine as raw materials in the presence of an aromatic hydroxyl compound shown by formula I (Ar is aromatic group) in a solvent such as pentane at 160-280 deg.C, especially 200-250 deg.C. In the operation, the reaction is carried out while eliminating ammonia as a by-product from the reaction system so that the ammonia concentration in the reaction solution is made <=1wt.% to give the objective compound. Phenol is preferably used as the aromatic hydroxyl compound and the amount of phenol used is properly 5-100mol based on 1mol compound shown by the formula II when the compound shown by formula II is used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention... Aliphatic O- is widely used as an intermediate raw material for masked isocyanates and aliphatic isocyanates.
This article relates to a method for producing aryl urethane. More specifically, an aliphatic primary fruit is reacted with an aryl carbamate or a mixture of an aryl carbamate and urea in the presence of an aromatic hydroxyl compound. The present invention relates to a method for producing aliphatic O-aryl urethane, characterized in that the reaction is carried out while removing by-product ammonia from the reaction system so that the ammonia concentration in the reaction solution is 1% by weight or less.

[Conventional technology]

Conventionally, aliphatic 0-aryl urethanes have been produced by reacting aromatic hydroxyl compounds with aliphatic isocyanates [for example, Keiji Iwata, Plastic Materials Course 2, Polyurethane Resins, 175 Shin, (Nikkan Kogyo Shimbunsha) ), 1969; K. C. Frisch,'Fun
dsental Chemistry and Cat
aly-sis of Polyurethans”+
Polyurethane Technology,P
．． F. Bruins, Ed. +Interscience
e Publishers, New York, 1969
, p. 11. ] - In this case, the aliphatic isocyanate is
Since it is obtained by the reaction of the corresponding aliphatic primary amine with phosgene (for example, British Patent No. 1,077,031), it has the following disadvantages. That is,
The use of highly toxic phosgene and the production of large amounts of corrosive hydrogen chloride gas as a by-product. The product may contain hydrolyzable chlorine compounds, which has the disadvantage that it is very difficult to remove this byproduct.

therefore. The process of reacting aromatic hydroxyl compounds with aliphatic isocyanates to obtain aliphatic O-aryl urethanes is not satisfactory.

JP 55-120551 (U.S. Patent No. 429750)
Specification No. 1) In the publication, aliphatic O-
A method for oxidatively converting group hydroxyl compounds into urethanes using noble metal catalysts has been described. However, there are no examples using aromatic hydroxyl compounds. However, this method also uses highly toxic carbon monoxide and expensive precious metal catalysts. To recover catalyst from urethane, which is a raw bottom material. This method has drawbacks such as requiring complicated operations and a large amount of cost.

Additionally, US Pat. No. 3,873,553 describes a method for producing N-alkyl-O-aryl urethane by reacting N-alkyl-N',N'-dialkyl urea, an aromatic hydroxyl compound, and hydrogen chloride gas. Are listed. However, this method also uses highly corrosive hydrogen chloride gas and consumes expensive and special urea compounds. The recovery of urethane from the hydrochloride of N,N-dialkylamine produced as a by-product has the disadvantage of requiring complicated operations and high costs. On the other hand, in US Patent No. 2,677,698. As a method for producing aliphatic monourethane without using phosgene, 1
In the step, N,N'-dialkyl urea is produced from aliphatic primary amine and urea, and in the second step, N,N''-dialkyl urea is reacted with a hydroxyl compound to produce aliphatic monourethane, and by-produced 1 However, there are no examples using aromatic hydroxyl compounds.However, this method not only has a low urethane yield, but also has a high reaction rate. The process is extremely complicated and unsatisfactory for industrial implementation, as it requires recycling equipment for the primary agones in one stage. Several methods have been proposed for producing aliphatic urethane by reacting with For example, U.S. Pat. No. 2,409,712 describes a method for producing an aliphatic O-alkyl monourethane by reacting an aliphatic primary amine and urea with an aliphatic alcohol. , Japanese Unexamined Patent Publication No. 5-5-14565
No. 7 (West German Patent No. 2917493) discloses that an aliphatic primary polyamine is reacted with an aliphatic, alicyclic, or aromatic aliphatic alcohol in the presence of urea to produce an aliphatic 0-alkyl polyurethane. A method of manufacturing is described.

Furthermore, as a method for improving these. Japanese Patent Publication No. 56-10315
No. 2 (West German Patent No. 2943551 Specification) Publication. JP 56-103153 (West German Patent No. 294355)
No. 0 Specification) Publication discloses that an aliphatic primary polyamine is converted into an aliphatic polyamine in the presence of urea and an O-aryl carbamate. A method for producing an aliphatic 0-alkyl polyurethane by reacting an alicyclic or aromatic aliphatic alcohol is described.

In this case, O-aryl rubamate is aliphatic or alicyclic.
It is described that the aliphatic 0-alkyl urethane produced by these methods is substituted with an aromatic aliphatic alcohol to form 0-7 alkyl carbagonate [Problem to be solved by the invention]. Because it is extremely thermally stable, it is difficult to decompose it into the corresponding aliphatic isocyanate and alcohol. Therefore, it is not satisfactory for use as an intermediate raw material for masked isocyanates and aliphatic isocyanates.

In this regard, it is known that aliphatic O-ester urethane easily decomposes into the corresponding aliphatic isocyanate and aromatic hydroxyl compound. Bayer
, ”Das Diisocyanat-Polyad
dionsVerfahren, 12 pages.
(1963). However, there is a method for producing aliphatic O-aryl urethanes from a one-step reaction of an aliphatic primary amine with an aromatic hydroxyl compound and an O-aryl carbamate or a mixture of an O-aryl carbamate and urea. This method has not yet been known and is much more difficult than the above-mentioned method using alcohol due to the following points.

First, O-aryl carba ξanoic acid is
It is known that aromatic hydroxyl compounds and cyanic acid, which are more easily decomposed than alkyl compounds, are more effective (J.
Gas Chromatog. + 3 volumes, 142 true,
(1965). Cyanic acid further reacts with aliphatic O-aryl urethanes to form cyanuric acid, allophanate. Irreversibly denatures to isocyanurate, etc. Therefore, the reaction yield of aliphatic O-aryl urethane is significantly reduced.

Second, O-ryol carbamate is combined with ammonia and 14
It easily reacts at temperatures above 0°C to form aromatic hydroxyl compounds and urea (J. Praktische Che
me, vol. 405 pages, 1834). O-alkyl carbanoate can be easily synthesized from urea and alcohol. It is known that it is extremely difficult to regenerate O-aryl carbamates from urea and aromatic hydroxyl compounds (for example, S.R. Sandler w.
．． Karo rOrganic Compound Compatibility Method IIJ by Functional Group,
248 pages, 1971, Hirokawa Shoten).

Therefore, the reaction yield of aliphatic O-aryl urethane is significantly reduced.

[Means to solve the problem]

First, the present inventors investigated urea. Aromatic hydroxyl compounds. Developed a method for producing aliphatic O-aryl urethanes through a one-step reaction between
No. 08744), in order to further increase the reaction yield. From the reaction of carbamine [0-7'J-l with an aliphatic primary amine, an excess of aromatic hydroxyl compound is required to stably exist the aliphatic O-allyl. This reaction is reversible and the equilibrium is significantly biased toward the original system, as expressed by Equation 1.2. Removal of by-product ammonia is essential for the reaction to proceed. Next, they discovered that aromatic hydroxyl compounds, which are one type of acid, bind strongly to ammonia, making it extremely difficult to remove ammonia using conventional methods.

R-(NHz)n + n ArOCONIIzR
−(NHz)n + ta ArOCONHz+
(ns) NHZOCONHz (In the above formula, n is an integer of 1 or more. A real number of n≧m>0. R represents an aliphatic group, an Ar aromatic group.) Next, the present inventors earnestly As a result of repeated studies, we found that by reacting an aliphatic primary amine with a mixture of O-aryl carbamate or O-aryl carbamate and urea in the presence of an excess of aromatic hydroxyl compound, the ammonia concentration in the reaction solution was reduced. By removing the by-produced ammonia from the reaction system so that the amount of ammonia becomes 1% by weight or less, a method for producing aliphatic O-aryl urethane in high yield has been discovered, and the present invention has been completed.

That is, the present invention provides a method for producing an aliphatic O-aryl urethane from an aliphatic primary amine, in which a) an aromatic compound represented by the following general formula: Ar-OH (wherein Ar represents an aromatic group); In the presence of a hydroxyl compound, an aliphatic primary amine and an O-aryl carbamate of the general formula Ar-OCONH2 (wherein Ar represents the same aromatic group), or a carbamic acid O- b) Reacting with a mixture of urea (NH2OCONH2) containing aryl at least 1% by weight, b) Reacting while removing by-product ammonia from the reaction system so that the ammonia concentration in the reaction solution is 1% by weight or less. The present invention provides a method for producing an aliphatic O-aryl urethane characterized by the following.

The aromatic hydroxyl compound used in the present invention is one in which a hydroxyl group is directly bonded to an aromatic group. It can be anything. For example, phenol; cresol (each isomer). Quizylenol (each isomer). Various alkylphenols such as ethylphenol (various isomers) and probylphenol (various isomers); methoxyphenol (various isomers). Various alkoxyphenols such as ethoxyphenol (various isomers); chlorphenol (various isomers). Promophenol (each isomer), dichlorophenol (each isomer). Dibromophenol (
Halogenated phenols such as methylchlorophenol (each isomer), ethylchlorophenol (each isomer), methylbromophenol (each isomer), ethylbromophenol (each isomer), etc. Halogen-substituted phenols; general formula A OH (A
is a simple combination or 10-, -S-, -302-, -
Represents a divalent group such as Co-, -CH2-, -C (R2)- (R is a lower alkyl group), and aromatic rings include halogen, alkyl group, alkoxy group, ester group, amide group, and cyano group. It may be substituted with substituents such as.
] Aromatic dihydroxyl compounds represented by: nitrophenol (each isomer), nitronaphthol (each isomer)
Nitro-substituted aromatic hydroxyl compounds such as; cyanophenol (each isomer), cyanonaphthol (each isomer)
Cyano-substituted aromatic hydroxyl compounds such as Such aromatic hydroxyl compounds may be used alone or in combination of two or more. Furthermore, it is preferable to use aromatic monohydroxyl compounds because they can be easily separated by distillation. Among them, it is more preferable to use phenol having a low boiling point.

The O-aryl carbagonate used in the present invention is the hydroxyl group (-OH) of the aromatic hydroxyl compound used.
) instead of an ξnocarboxyl group (-0CONH2)
The amount of the aromatic hydroxyl compound used in the present invention, in which . per mole of O-aryl carbanoate used.
It is preferable to use it in an amount of 5 mol or more and 100 mol or less. When a mixture of urea and O-aryl carbamate is used, it is preferably used in an amount of 5 to 100 times the sum of the moles of urea and O-aryl carbamate. If it is less than 5 times, carbamic acid O
- The yield of aliphatic O-arylurethane decreases because aryl or urea is modified to aliphatic O-arylurethane. Moreover, if the amount is more than 100 times, the space-time yield will decrease, so it is not a good idea for industrial implementation.

The amounts of urea and O-aryl carbamate used in the present invention are preferably such that the sum of urea and O-aryl carbamate is 0.5 mole or more per mole of amino group of the aliphatic primary amine. ．． A more preferable usage amount is 0.8 mol or more and 2 mol or less of urea per 1 mol of urea group. If the amount of urea is less than 0.5 mol per mol of amino group of the aliphatic primary amine, complexly substituted urea compounds will be produced as by-products.
If the amount is more than 2 moles, a complexly substituted urea compound may be produced as a by-product, and unreacted urea and O-aryl carbaxianoate may remain, which is not preferable.

The aliphatic primary amine used in the present invention may be any amine in which one or more primary amino groups are bonded to an aliphatic carbon atom; It may be an amine or an aromatic aliphatic primary amine.

Examples of such aliphatic primary monoamines or polyamines include methylamine, ethylamine, probylamine (all isomers), butylamine (all isomers), and pentylamine (all isomers). Hexylamine (each isomer)
, aliphatic primary monoamines such as dodecylamine (each isomer); ethylenediamine, diaminopropane (each isomer), diastra butane (each isomer), diaξnopentane (
Aliphatic primary diamines such as (each isomer), diaminohexane (each isomer), diaminodecane (each isomer); 1,
2.3-}ria-ξ-nopropane, triaminohexane (each isomer), triaminononane (each isomer), triaminododecane (each isomer).1.8-Diamino-4-aξ-nomethyl-octane. 2.6-diaminocapric acid-2-
Aliphatic 1 such as aminoethyl ester, 1,3,6-triaξnohexane, 1,6,1l-triaminoundecane, etc.
Class triamines; cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, diaminocyclobutane. Diaminocyclohexane (each isomer), 3-aminomethyl-3.5.5-trimethylcyclohexylamine. Alicyclic primary heptanoamines and polyamines such as triaminocyclohexane (each isomer); benzylamine, di(aξnomethyl)benzene (each isomer). Aminomethylpyridine (isomers). Di(aminomethyl)pyridine (each isomer), aξnomethylnaphthalene (each isomer), di(aminomethyl)naphthalene (
These include aromatic aliphatic primary monoamines and polyamines such as various isomers). In addition, in the aliphatic groups, alicyclic groups, and aromatic groups that make up the skeletons of these primary amines, some of the hydrogen atoms are halogens, alkyl groups, and alkoxy groups. Ryoryl group, ester group, sulfone group. It may be substituted with a substituent such as a cyano group, or it may have an unsaturated bond in its skeleton. Ether bond, ester bond, thioether bond. It may contain a sulfone bond, a ketone bond, etc.

Although it is a preferred practice to use an excess amount of an aromatic hydroxyl compound as a solvent in the practice of this invention, other suitable solvents may also be used.

Examples of such solvents include pentane, hexane, and heptane. Aliphatic hydrocarbons such as octane and decane;
Benzene, toluene. Xylene. Aromatic hydrocarbons such as mesitylene; nitriles such as acetonitrile and penzonitrile; sulfones such as sulfolane, methylsulfolane and dimethylsulfone; tetrahydrofuran. Ethers such as 1.4-dioxane and 1.2-dimethoxyethane;
Examples include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and ethyl benzoate.

Furthermore, chlorobenzene. Dichlorobenzene. Frequently halogenated aromatic hydrocarbons such as trichlorobenzene, fluorobenzene, chlorotoluene, chlornaphthalene, and promonaphthalene; chlorhexane, chlorocyclohexane. Octalogenated aliphatic hydrocarbons or halogenated alicyclic hydrocarbons such as monotrichlorotrifluoroethane, methylene chloride, and carbon tetrachloride are also used as solvents.

In carrying out the present invention, it is preferable to carry out the reaction at a temperature in the range of 160 to 280°C. If the reaction is carried out at a temperature lower than 160°C. Because aromatic hydroxyl compounds and aliphatic primary amines, ammonia, and urea bond strongly, the reaction may be slow. This is not preferable because little reaction occurs or the amount of complexly substituted urea compounds increases.

If the reaction is carried out at a temperature higher than 280°C. urea and carba ξ
O-aryl phosphoric acid decomposes significantly. This is undesirable because the aromatic hydroxyl compound may be dehydrogenated or the aliphatic O-aryl urethane, which is a raw material, may be decomposed or modified, leading to a decrease in yield. In this sense, a more preferable temperature range is 190 to 260"
It is C. A more preferred temperature range is 200-250°C.

In carrying out the present invention. The amount of ammonia produced as a by-product in the reaction system that should be removed varies somewhat depending on the reaction temperature and the difference in basicity between the primary amine and the aromatic hydroxyl compound.
It is almost constant regardless of the composition of the reaction system, and it is very important to remove the ammonia so that the concentration in the reaction solution is 1% by weight or less. If the ammonia concentration is 1% by weight or more, the aliphatic O-
Not only is it almost impossible to obtain aryl urethane, but
This is because the yield of aliphatic O-aryl urethane decreases significantly as the O-aryl carbamate and urea are modified. Furthermore, in order to increase the yield of aliphatic O-aryl urethane, the ammonia concentration in the reaction solution must be 0.5% by weight.
It is preferable to remove the following. One of the preferred embodiments for removing ammonia by-produced in the reaction system is a reactive distillation method. In other words, the reactive distillation method is a method in which ammonia, which is successively produced during a reaction, is separated in gaseous form by distillation. To increase the efficiency of ammonia distillation, it can also be carried out under boiling of a solvent or an aromatic hydroxyl compound.

Another preferred method for removing ammonia by-produced in the reaction system is to use an inert gas.
That is, by entraining ammonia, which is successively produced during the reaction, in gaseous form with an inert gas. This is a method of separating it from the reaction system. It is also a preferable method to introduce such inert gases, such as nitrogen, helium, argon, carbon dioxide, methane, ethane, propane, etc., singly or in combination into the reaction system. In addition, a gaseous low-boiling organic solvent can also be used to remove by-product ammonia from the reaction system in the same way as an inert gas.

Examples of such low boiling point organic solvents include halogenated hydrocarbons such as dichloromethane, chloroform, and carbon tetrachloride; pentane and hexane. Heptane, benzene. Lower hydrocarbons such as toluene and xylene; ketones such as acetone and methyl ethyl ketone; and ethers such as tetrahydrofuran and dioxane can also be used.

Furthermore, a catalyst can also be used for the purpose of lowering the temperature or increasing the reaction rate in methods using reactive distillation, inert gas, etc. Such catalysts include, for example, rare earth elements, antimony, and bismuth, as well as their oxides, sulfides, and salts; elemental boron and boron compounds;
Nium family. Carbon group, titanium group metals and oxides and sulfides of these metals; carbon group excluding carbon in the periodic table,
Carbides and nitrides of titanium group, vanadium group, and chromium group elements are preferably used. When a catalyst is used, the ratio of the catalyst to the aliphatic primary amine can be adjusted to any desired ratio, but the weight ratio to the aliphatic primary amine is usually 0.000.
It is preferable to use 1 to 100 times as much catalyst.

Another preferred embodiment for removing ammonia by-produced in the reaction system is a method of separating ammonia by adsorbing it onto an adsorbent. The adsorbent used is. for example. 16 such as silica, alumina, various zeolites, diatomaceous earth, etc.
Adsorbents that can be used under temperature conditions of 0 to 280'C can be used. Furthermore, in order to remove ammonia produced as a by-product in the reaction system. Reactive distillation method, method using inert gas, etc. It is also possible to use a combination of methods such as separation by adsorption on an adsorbent.

The reaction pressure when carrying out the present invention depends on the composition of the reaction system and the reaction temperature. How to remove ammonia. It varies depending on the type of reactor, etc. It is usually preferable to carry out the reaction in a pressure range of 0.1 to 50 atm. More preferably, 1 to
A pressure range of 30 atmospheres is preferred for industrial practice.

Similarly, reaction time also depends on the composition of the reaction system and the reaction temperature. Although it depends on the ammonia removal method and the type of reaction equipment, it usually takes several tens of minutes to several tens of hours. Preferably it is several tens of minutes to several hours. It is better to be as short as possible. There are no limitations to the type of equipment used to carry out the present invention. For example, there is a method in which the reaction proceeds while the raw material liquid flows down inside a vTi-type tubular device, and by-product ammonia is taken out from the top of the device and removed, or a method is used in which the reaction is carried out using a tank-type device and the by-product is Methods that remove ammonia by extracting it into the gas phase, and methods that combine these methods are preferably used. Furthermore, it is also a preferable method to provide a distillation column and/or a partial condenser, etc. above these devices, if necessary.

Moreover, the present invention is a batch method. Any continuous method can be used.

The invention is suitable for producing aliphatic O-aryl monourethanes and polyurethanes. Production of 1,6-hexamethylene-o,o'-diphenyl urethane, which is a masked isocyanate of 1,6-hexamethylene diisocyanate, which is used in large quantities industrially, 3-isocyanatomethyl-3.5. 5-}3-Phenoxylponylaminomethyl which is a masked isocyanate of (Hpt) trimethylhexyl isocyanate = 3.5.
5-}Production of trimethyl-1-phenoxycarbonylated ξ-nocyclohexane. This method is also suitable for producing m-xylylene-0,0-diphenyl urethane, which is masked isocyanate-1 of m-xylylene diisocyanate. [Effects of the Invention] The present invention has the following advantages over conventional methods. 1) Make sure that the ammonia concentration in the reaction solution is 1% by weight or less.
By conducting the reaction while actively removing by-product ammonia from the reaction system, aliphatic O-aryl urethane can be obtained in high yield. 2) Because it does not use phosgene or carbon monoxide. There are no problems such as corrosion or toxicity, and there is no problem with large amounts of hydrogen chloride gas being produced as by-products. Furthermore, it is inexpensive because it does not require the use of expensive precious metal catalysts. 3) One-stage reaction. The process is simple.

It is advantageous for industrial implementation because of its high urethane yield. moreover. Since the obtained urethane is an aliphatic O-aryl urethane, it can be easily thermally dissociated and is advantageous for use as an intermediate raw material for masked isocyanates and aliphatic isocyanates.

〔Example〕

Next, the present invention will be explained in more detail with reference to examples. The present invention is not limited to these examples. To quantify the amount of ammonia in the reaction solution, extract the reaction solution with 10 times the amount of water or more to make an aqueous solution. Ammonium ions were quantified using ion chromatography (IC). The ion chromatography column and detector are TSK-getIC-Cation and CM-80 manufactured by Tosoh Corporation.
00, and a 2mM concentrated nitric acid aqueous solution was used as the eluent at 1 min.
．． 21d sink. Measured at 35°C. In addition, the amount of ammonia in the reaction gas can be determined by gas chromatography (GC).
). Aromatic hydroxyl compounds. Quantification of O-aryl carbanoate and aliphatic primary amine was performed by gas chromatography (GC) and liquid chromatography (LC). Quantification of urea, O-aryl carbanoate, and aliphatic O-aryl urethane was performed by gel vermutation chromatography (CPC) and LC. Example 1 Thermometer. Stirrer. Reflux device. and 1 with gas inlet pipe
00〇 29 g of 1,6-hexamethylene diamine (hereinafter referred to as HDA), 75 g of O-phenyl carbamate, and 470 g of phenol were placed in a four-necked glass flask, and nitrogen gas was added through a ball filter that reached the bottom of the reactor. Under boiling phenol (17
The reaction was carried out with stirring at a temperature of 0 to 180°C. moreover,
The following operation was repeated every 20 hours. first. The entire amount of the reaction solution was collected and its weight (g) was measured. Next, collect 1.0g.
1,6-hexamethylene-0.0'- contained in the reaction solution
Diphenylurethane (}IDPh) and ammonia (
NH3) was placed in place. From this value, 1,6-hexamethylene-o,o'- per mole of HDA charged
The molar yield % of diphenyl urethane was calculated.

By 80 hours, 120 g of phenol containing ammonia had flowed out from the upper part of the reflux vessel. The results are shown in Table 1.

From Table 1, 1,6-hexamethylene-o,o'-diphenyl urethane can be obtained with a high yield of 82% by actively removing ammonia by-produced in the reaction solution to 0.04% by weight. I understand that In addition, the larger the weight percent of ammonia by-produced in the reaction solution, the more 1,6-hexamethylene -o,o''
-It can be seen that the yield of diphenyl urethane is low. Therefore, it has become clear that there is an equilibrium expressed by equation (1) above, and that the equilibrium is biased toward the original system. However, since the yield decreased after 80 hours of reaction, it became clear that a denaturation reaction was occurring at the same time. Therefore, it was found that there is an optimum value for the reaction time.

Comparative Example 1 The same operation as in Example 1 was performed except that nitrogen gas was not flowed. Stirred at reflux temperature (179-182'C) for 60 hours. The reaction solution contained 1.0% by weight of ammonia, but no l,6-hexamethylene-0,O'-diphenylurethane was detected. There was also no leakage from the upper part of the reflux vessel. When phenol was distilled off from the reaction solution after 60 hours,
44 g of a tan solid were obtained.

Therefore, the sample was extracted with dimethylacetamide, which is a good solvent for (1),6-hexamethylene-0.0'-diphenylurethane, and further analyzed. However, from this extract also 1,6
-Hexamethylene 10,0゛1 diphenyl urethane was not detected at all.

Comparative Example 2 The same operation as in Comparative Example 1 was performed except that 650 g of n-octanol, a type of alcohol, was used instead of phenol. The mixture was stirred at reflux temperature (180-182°C) for 20 hours. When n-octanol and phenol were distilled off from the reaction solution, 103 g of pale yellow reaction raw bottom material was obtained. There was 87g of hexamethylene di(n-octylurethane) in it. Preparation} per IDA, 1
．． The yield of 6-hexamethylene-o,o'-di(n-octylurethane) was 81%.

From Example 1 and Comparative Example 1, the following was found.

In the reaction for producing aliphatic O-aryl urethane from O-aryl carboxylate and aliphatic primary amine in the presence of an aromatic hydroxyl compound, it is extremely difficult to remove ammonia from the reaction system. Therefore, unless ammonia is efficiently removed, the desired aliphatic O-aryl urethane cannot be obtained. From Example 1, it was found that ammonia could be effectively removed by combining reactive distillation and a method using an inert gas. Furthermore, Comparative Example 2 shows that ammonia can be easily removed without using any special method, so aliphatic O-alkyl urethanes can be easily produced from alcohols, O-aryl carboxylic acids, and aliphatic primary amines. However, from Comparative Example 1, aliphatic O-
It is clear that the fact that it is extremely difficult to remove ammonia in the method for producing aryl urethanes cannot be predicted from the method for producing aliphatic O-alkyl urethanes.

Examples 2 to 9 Vertical reaction tube 1 with a volume of 2 liters filled with filler as shown in Fig. 1
Raw material solution A was continuously introduced from the upper part of the reaction tube 1, and reaction solution B was continuously collected from the lower part of the reaction tube 1. On the other hand, nitrogen gas C is introduced from the lower part of the reaction tube 1, and the cooling reflux device 2 is placed at the upper part of the reaction tube.
Then, the reaction gas E was recovered through the gas-liquid separator 3. At this time. The condensed fraction D accompanying the gas was continuously collected from the bottom of the gas-liquid separator. HDA4 6 4 g. O-phenyl carbamate 15
A raw material solution consisting of 15 g of phenol and 7520 g of phenol was used. The reaction pressure was 6 atm (Examples 8 and 9 were 12 atm)
The temperature of the cooling reflux device 2 was 140″C, and the amount of nitrogen gas was 2Of per hour in terms of standard conditions.Reaction temperature (°C)
The inflow amount (g/}lr) of raw material liquid A was conducted under various conditions shown in Table 2. Average residence time was 8 minutes to 45 minutes. After the reaction is complete, the entire amount of reaction solution B is collected and its weight (g
) was measured, and then 1,6-hexamethylene-0,0'-diphenylurethane (HDPh) contained in reaction solution B was measured.
and the weight percent of ammonia (Nl{3).

From this value, the molar yield% of 1.6-hexamethylene-0,0'-diphenylurethane per mole of HDA charged was calculated. The results are shown in Table 2.

Examples 10-11 and Comparative Example 3 The same operations as in Example 2 were performed except that the composition of raw material A was changed as follows. In Example 10, HDA464g. Kalba ξ
O-phenyl phosphate 5 7 6 g. 252 g of urea.
A raw material solution consisting of 7520 g of phenol was used, and in Example 11, 4 6 4 g of HDA was used. Carbamic acid O-
Phenyl 5g. Urea 502 g. Then, a raw material liquid consisting of 7520 g of phenol was used. In Comparative Example 3, HDA
A raw material solution consisting of 464 g of urea, 504 g of urea, and 7520 G of phenol was used. The result is the second
Shown in the table.

From the results of Example 2 in Table 2 in the margin below, it is clear that ammonia as a by-product in the reaction solution is reduced to 0.
．． By actively removing up to 0.01% by weight, 1. 6-
It was found that hexamethylene-0.0'-diphenyl urethane could be obtained continuously with a high yield of 94%. Also.
From the results of Examples 2 to 6, the more ammonia by-produced in the reaction solution is removed, the more 1,6-hexamethylene-O. O″-
High yield of diphenyl urethane and 1.6-
To obtain hexamethylene-0,0'-diphenyl urethane. The ammonia concentration as a by-product in the reaction solution was reduced to 1% by weight.
It should be removed until It has been found that in order to obtain a higher yield, it is preferable to remove the ammonia concentration in the liquid to 0.5% by weight.

moreover. From the comparison of Example 2 and Examples 7 to 9, 1.6-
In order to obtain hexamethylene-o,o''-diphenyl urethane, the reaction temperature is preferably in the range of 160°C to 280°C, and in order to obtain a higher yield, the reaction temperature is preferably in the range of 190°C to 260°C. It was found that it is preferable to have a range of It was found that high yields could be obtained.

Comparative Example 4 Except for changing the composition strength of raw material A as follows. The same operation as in Example 2 was performed, HDA4 6 4 g. O-phenyl carbanoate 1151g. and phenol 3764g
The reaction pressure was 6 atm and the reaction temperature was 2
20'C. The flow rate of raw material liquid A was 100 g/hour, and the nitrogen gas flow rate was 201 g/hour in terms of standard conditions. After the reaction was completed, 5169 g of reaction solution B was recovered. 1.6 in this
-Hexamethylene-o,o'-diphenylurethane is 5
．． It contained 5% by weight, and 0.01% by weight of ammonia. From this value, 1.0% per mole of HDA charged.
The yield of 6-hexamethylene-o,o'-diphenylurethane was 19%. From this, it was found that when the amount of the aromatic hydroxyl compound is less than 5 times the mole of the ξ-aryl carboxylate, the yield of urethane decreases.

Example 12 The same operation as in Example 2 was carried out by changing the raw material Aom as follows. A raw material solution consisting of 464 g of HDA, 1268 g of O-(m-cresyl) carbamate, and 8640 g of m-cresol was used, and the reaction pressure was 6 atm. The reaction temperature is 22
The temperature was 0°C, the flow rate of raw material liquid A was 100 g/hour, and the amount of nitrogen gas was 20 N/hour (converted to standard conditions). After the reaction was completed, 9684 g of reaction solution B was recovered. Among these, 1,
6-hexamethylene-o,o'-di(m-cresyl urethane) was 15.0% by weight. and ammonia was contained in an amount of 0.01% by weight. From this value, the yield of 1.6-hexamethylene-o,o'-di(m-cresyl urethane) per mole of HDA charged was 94%.

Example 13 Except for changing the composition of raw material A as follows. The same operation was performed under the same reaction conditions as in Example 12. That is, }IDA4
64g. Carbatanate 0-(0-chlorophenyl)1
441g. A raw material solution consisting of 10,280 g of O-chlorophenol was used. After the reaction is complete, reaction solution B has a concentration of 106
12g was recovered. Among these, 1,6-hexamethylene-o,o'-di (0-chlorophenyl urethane) is 14.
7% by weight, and ammonia 0. Contained %Ol by weight. From this value, the yield of 1.6-hexamethylene-o,o'-di(0-chlorophenylurethane) per mole of HDA charged was 92%.

Example 14 The same operation was carried out under the same reaction conditions as in Example 12, except that the composition of raw material A was changed as follows. That is, HDA46
4g. Carbamic acid O-(2-naphthol) 1571g
A raw material solution consisting of 1520 g of 2-naphthol 1 was used. After the reaction was completed, 12,574 g of reaction solution B was recovered. This contained 13.2% by weight of 1,6-hexamethylene-0.0'-di(2-naphthylurethane) and 0.01% by weight of ammonia.

From this value, the yield of 1.6-hexamethylene-o,o'-di(2-naphthylurethane) per mole of HDA charged was 91%.

Example 15 Except for changing the composition of raw material 8 as follows. The same operation was carried out under the same reaction conditions as in Example 12. went. In other words. 3-Aξ
680 g of nomethyl-3.5.5-trimethylcyclohexylamine (IPA). O-phenyl carbamate 11
A raw material liquid consisting of 51 g and 7520 g of phenol was used.

After the reaction was completed, 8628g of reaction solution B was recovered. Among these, 3-.phenoxycarbonylanomethyl-3.5.
5-}limethyl=1-phenoxycarbonylaminocyclohexane was 17.3% by weight, and ammonia was 0.5% by weight.
It contained 01% by weight. From this value, 3-phenoxycarbonylaminomethyl-3.
The yield of 5.5-}limethyl-1-phenoxycarbonylaminocyclohexane was 92%. Example 16 The raw materials were changed as follows. The same operation was performed under the same reaction conditions as in Example 12. That is, 544 g of m-xylylenediamine, 1151 g of O-phenyl carbamate. A raw material solution containing 7529 g of phenol was used. After the reaction was completed, 8387g of reaction solution B was recovered. Among these, m-xylylene-o,o'-diphenylurethane is 1
7.2% by weight, and 0.01% by weight of ammonia. From this value, the yield of m-xylylene-o,o''-diphenylurethane per mole of m-xylylene diamine charged was 96%.

Example 17 Change the composition of raw material A as follows. The same operation was carried out under the same reaction conditions as in Example 12, except that the nitrogen gas amount was 10 liters per hour (converted to standard conditions). That is, 516 g of n-octylamine, 57 g of O-phenyl carbamate.
A raw material solution consisting of 5 g of phenol and 3760 g of phenol was used. After the reaction is complete. 4440g of reaction solution B was recovered.

Among these, n-octyl 10-phenyl urethane is 21.
8% by weight. and ammonia was contained at 0.01% by weight. From this value, the yield of n-octyl 10-phenyl urethane per mole of n-octylamine charged was 97%.

Example 18 Using a vertical reaction tube 1 with a volume of 8 liters filled with a filler, raw material A was
Example 2 except that the composition and reaction conditions were changed as follows.
The same operation as }{DA 464 g, O-phenyl carbamate 1 1 5 1 g, and phenol 1
Using 5,040 g of raw material liquid, the reaction pressure was 462 atm, the reaction temperature was 235'C, and the temperature of cooling refluxer 2 was 10
0℃. The flow rate of raw material liquid A was 1,500 g/hour, and the amount of nitrogen gas was 1,500 g/hour in terms of standard conditions. Average residence time was 30 minutes. After the reaction is complete, reaction solution B has a concentration of 158
26 g was recovered. This contained 8.82% by weight of 1,6-hexamethylene-o,o'-diphenylurethane and 0.004% by weight of ammonia. From this value, the yield of 1,6-hexamethylene-o,o'-diphenylurethane per mole of HDA charged was 98%. Furthermore, by the end of the reaction, the amount of reaction gas E was recovered as 12,561 liters in terms of standard conditions, and 12.5 liters of ammonia gas was collected in reaction gas E by GC.・Since it contained 5% by volume,
This means that 99% of the theoretical amount of ammonia was recovered as a gas. Furthermore, using a rotary evaporator, phenol was distilled off from reaction solution B to obtain 1562 g of pale yellow solid. Next, convert this solid into 3Il with i o o 'c.
Dissolved in xylene. Recrystallization yielded 1351 g of white solid. 1.6-hexamethylene-0.0
The purity of '-diphenyl urethane was determined to be 99 by GPC analysis.
% by weight.

Example 19 The same operation as in Example 18 was performed except that n-hexane was used instead of nitrogen gas. 385 g of n-hexane per hour was introduced in gaseous form into the lower part of the vertical reaction tube 1 via an evaporator. After the reaction was completed, 15,914 g of reaction solution B was recovered.
In this, 1,6-hexamethylene 10,o'-diphenyl urethane is 8.68i weight %, and ammonia is 0.
It contained 0.04% by weight. From this value, the yield of 1.6-hexamethylene-o,o' diphenyl urethane per mole of HDA charged was 97%. Furthermore, phenol was distilled off using a rotary evaporator, and then 100"C
, 1337g when recrystallized from xylene of 3ffi
A white solid was obtained.

The purity of L 6-hexamethylene-o,o'-diphenyl urethane was 99% by weight by GPC analysis.

[Brief explanation of the drawing]

FIG. 1 is a process explanatory diagram of Examples 2 to 19. In the figure, 1 is a vertical reaction tube and 2 is a cooling reflux device. 3 is a gas-liquid separator, A is a raw material liquid, and B is a reaction liquid. C represents nitrogen gas, D represents condensation, and E represents reactive gas. Figure 1

Claims (1)

[Claims] 1. A method for producing an aliphatic O-aryl urethane from an aliphatic primary amine, a) represented by the following general formula: Ar-OH (wherein Ar represents an aromatic group) In the presence of an aromatic hydroxyl compound, an aliphatic primary amine and an O-aryl carbamate or an O-aryl carbamate of the general formula Ar-OCONH2 (wherein Ar represents the same aromatic group) b) Reacting with a mixture of urea (NH2OCONH2) containing 1% by weight or more of A method for producing an aliphatic O-aryl urethane.