JPS59167555A - Production of urethane compound - Google Patents

Abstract

PURPOSE:To facilitate the condensation and thermal decomposition reaction in the preparation of the titled compound, by reacting an aromatic mononitro compound with a compound having phenolic hydroxlyl group and carbon monoxide under specific condition, and separating the produced urethane by crystallization. CONSTITUTION:An aromatic mononitro compound (e.g., nitrobenzene) is made to react with a compound having phenolic hydroxyl group (e.g. phenol) and carbon monoxide. The reaction is carried out in the presence of a catalyst containing palladium, vanadium and/or iron, tertiary amine, and halogen, using less than equimolar amount of the phenolic hydroxyl group based on the nitro group. After the rection for 1-10hr at 100-250 deg.C, preferably 140-200 deg.C, the solid catalyst component is separated from the reaction liquid by filtration to obtain the objective urethane. The mother liquor separated after crystallization and the solid catalyst component can be recycled into the reaction system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method VC for producing a urethane compound.

As a method for producing organic incyanates, a method in which amine is reacted with phosgene is currently widely used. However, even if nitro compounds were reduced with hydrogen 1, in order to avoid this method which consumes large quantities of expensive electrolytic chlorine, a method was discovered in which the nitro compounds were reductively carbonylated using -carbon oxide. It's been coming. This method can be roughly divided into two polar types: a method in which the reaction is carried out in an inert solvent to directly obtain incyanite, and a method in which urethane is obtained using alcohol as a solvent and then thermally decomposed to obtain isocyanate. . Since the reaction rate of both types is generally slow and the reaction selectivity is low, in recent years, the development of ViL:J#: molecules has been carried out.

Currently, the targets are mainly the production methods of toluene diisocyanate (TD) and diphenylmethane diisocyanate (MDI), which are the most consumed incyanate compounds.In the case of TD, dinitrotoluene and ordinary aliphatic A process is established in which diurethane of alcohol is produced, easily separated by crystallization, and thermally decomposed.

In the case of the L 7jh L MD process, the aliphatic alcohol urethane produced by carbonylating nitrobenzene is highly susceptible to organic solvents, and cannot be completely crystallized. Therefore, in order to separate the product, urethane with a high boiling point must be vaporized under high vacuum.

In addition, thermal decomposition performed after combining this urethane with formalin has a disadvantage in that the thermal decomposition temperature at which incyanate is completely absorbed is high, and therefore the MDI produced is easily converted into hartz.

In order to solve these process difficulties, we conducted a study and decided to carry out the carbonylation reaction of an aromatic mononitro compound in the presence of a phenolic hydroxyl group-containing compound C, and in the presence of an excess amount of nitro groups than the existing phenolic hydroxyl groups. It has been found that the urethane produced by the process can be crystallized and separated, and thermal decomposition containing M can be easily carried out.

That is, the present invention provides a method for producing a urethane compound by reacting an aromatic mononidro compound with a compound containing a phenolic hydroxyl group and carbon monoxide, in which the phenolic hydroxyl group is less than equimolar to the nitro group, and palladium , ■ Vanadium and/or iron, ■ Tertiary amine, ■ Conduct the reaction in the presence of a catalyst containing a halogen atom, and after removing the solid catalyst from the reaction solution, the urethane compound is crystallized and separated. The present invention relates to a method characterized by:

The present invention will be explained in detail below. The aromatic mononitro compounds used in the present invention include the following.

Nitrobenzene% o I'' I and p-nitrotoluene, O-nitro-p-xylene, o-, m-, and p-chloronitrobenzene, /-promoter nitrobenzene, o-, m-, and p-nitrophenyl carbamate, 0 -,.

Examples include m-oxhyp-nitroaninol, ethyl-p-nitrobenzoate, 3-nitroanhydride/l/acid, nitronaphthalene, and the like.

However, the dinitro compounds 1 and A can be used together with polynitro compounds as long as they have appropriate solubility in the reaction solution and there is no problem in separating the quality of the urethane produced. The initial concentration of these aromatic mononitro compounds in the reaction solution is 7 to 7 Owt, preferably! ~30wt
% of the phenolic hydroxyl group-containing compounds include the following.

Phenol, chlorophenol, cresol, ethylphenol, nlopylphenol, butylphenol, as well as tsutsuji alkylphenol, β-naphthol, anthrol, 7-enanthrol, and the like are used.

These phenols may be further substituted with a direct group such as a halogen atom, sulfoxide, sulfone, or carboxylic acid ester group. The amount of phenolic hydroxyl group to be used is equivalent to 1,000 moles to the nitro group. In the above case, the conversion rate of the nitro group decreased, and after the reaction, the phenolic hydroxyl group-containing compound, which is present at 111 J, crystallized first, resulting in a decrease in the urethane di-crystallization yield. Or, the presence of a phenolic hydroxyl group-containing compound may lead to higher solubility in urethane, resulting in crystallization.

Examples of the palladium component include palladium metal and compounds such as oxides, halides, cyanides, thiocyanides, sulfates, and acetates. The palladium component is an example.

θ-~ on carriers such as activated carbon, graphite, and silica! It may also be used with a heavy loading. The amount of this catalyst to be used is from 0.5 to 0.5. 2θmmol/匈, preferably 0. ♂~/jmiol/ng, 10 If the amount is small, good activity cannot be obtained.

The vanadium component is usually vanadium metal or, for example, vanadium trichloride, vanadium monochloride, vanadium oxydichloride, vanadium oxytrichloride, vanadium pyrrovanadate, metavanadate, sodium orthovanadate. , potassium metavanadate,
Ammonium metavanadate, vanadium sulfate, vanadium vanadium, vanadyl sulfate, vanadyl oxalate, vanadium oxyacetylacetonate, VO(OO2H,),,V
(Co), Sudo (7E /< Nadium compounds are mentioned. The amount of vanadium component used is /~7 om as metal for the compound having a phenolic hydroxyl group.
lll0I/kg, preferably ke, 2-60mm
It is ol/jig. Good results cannot be achieved even if the amount used is too large or too little.

The amount of the vanadium component used is usually as described above; the metal ratio to the palladium component is 0.7~/! It is preferable to select from the range of 0.5 to 72 times by mole, preferably from 0.5 to 72 times by mole.

The iron component is usually a ferrous metal or, for example, ferrous chloride, ferrous dove, ferrous/iron oxide, ferrous oxide, iron hydroxide, ferrous sulfate, ferrous sulfate, iron acetylacetonate, Examples include iron compounds such as iron phthalocyanine. The amount of iron component to be used is 0+3~j Om mol/kg, preferably 0 as a metal for the compound having phenol hydroxyl group'f.
．． 5 to 30 mmol/k, g, usually 0.02 to 72 times the metal ratio relative to the palladium component,
The desired IL value is preferably in the range of 0.7 to 70 times by mole. High tactile activity cannot be obtained if the amount of iron component is too high or too low. It's a trench. The ratio of iron component to vanadium component is usually 0.07 to .07 as a metal ratio. 2
0 mole times, good -tL-< is o, os ~ 10 mole times. Incidentally, the vanadium component and the iron component may be used by being supported on a carrier in the same way as the palladium component, and in this case, even if each fraction is co-supported on the same carrier, -! Alternatively, they may be supported on separate carriers.

The halogen atom is used, for example, in the form of a hydrogen halide such as hydrogen chloride, hydrogen bromide or hydrogen iodide, and is usually supplied to the reaction system. ) Hydrogen halide may be directly supplied to the reaction system, but for example, it is preferable to supply it as hydrogen halide carrier of the tertiary amine described below.
It can also be used as a halide of the above-mentioned palladium, vanadium, or iron, and in this case, it may be used alone with the hydrogen halide of the tertiary amine. The amount of halokene atoms used is 0.3- to the total metals in the catalyst fraction.
4θ molar times, preferably L<keOo and ~Zθ molar times. If the amount of halogen atoms used is small, sufficient contact af is achieved.
On the other hand, if there is too much Al, side reactions will occur, which is not preferable.

Tertiary amines usually include aliphatic amines such as triethylamine, tripropylamine, and tributylamine;
N,N-dimethylaniline.

Aromatic amines such as N,N-diethylaniline, triphenylamine, N,N-dimethylcyclohexylamine, JN-diethylcyclohexylamine, N,λ
-Alicyclic amines such as sinolovircyclohexylamine, or pyridine, chlorpyridine, brompyridine, fluoropyridine, 2,6-dichloropyridine, g7enylpyridine, picoline, -monomethyl-! -Ethylpyridine, 2,6-lutidine, collidine, -monovinylpyridine, -monochlorethermethylpyridine, terphenylthiopyridine, comethoxypyridine, 6-dicyazpyridine, α-phenyl picolinate, α-methyl picolinate, α-Picolinamide C-like pyridine 7641, quinoline, inquinoline, chlorquinoline, J, 6,
7. Examples include quinoline derivatives such as J'-tetrahydroquinoline, heterocyclic amines such as pyrrole derivatives, indole derivatives, indole derivatives, and carbazole S-forms, and pyridine fatty conductors or quinoline derivatives are usually preferred. The amount of tertiary amine used is usually 0.07 to 20 moles, preferably 7 to 20 moles, relative to the halogen atom.
70 moles. If the amount of tertiary amine used is too large, the reaction rate will be slow, while if it is too small, corrosion of the reactor will increase, which is not preferable. Further, when a 10-hydrogenide salt is used as the tertiary amine, it can serve as both the tertiary amine component and the halogenated water component.

In the present invention, since the aromatic nitro compound is used in an excessive amount, it may be used as a solvent, or an oil-free solvent is generally used. Specifically, aromatic hydrocarbons such as evabenzene, toluene, xylene, acetonitrile,
Nitriles such as benzonitrile, sulfones such as sulfolane, 2-) chloride/, 2-chlorogenated aliphatic hydrocarbons such as 2-trifluoroethane,
chlorobenzene, dichlorobenzene, trichlorobenzene, etc.; Ketones, ethyl acetate, butyl acetate, diacetoxyethane, diacetoxybutane, phenyl acetate, dimethyl phthalate,
Esters such as diethyl phthalate, dibutyl phthalate, dioctyl phthalate, trioctyl trimellitate, etc. are used.

These inert solvents must provide appropriate solubility for aromatic mononitro compounds, phenolic hydroxyl group stone-containing compounds, urethane, amines produced by-products in the reaction, urea compounds, catalyst components, etc. No. In addition, after the reaction, the solid catalyst component is filtered, and in some cases, some components are distilled off and then cooled. When crystallizing urethane, unreacted raw materials and catalyst components are dissolved and the crystallization base 'e, K'A distillate is obtained. For this reason, the non-housing solvent must be selected appropriately in terms of boiling point, solubility, etc.

If the aromatic mononitro compound used in excess has the above-mentioned appropriate physical properties, an inert solvent may not be used, or a simple inert solvent may be used to speed up the reaction. It is also possible to reduce the energy cost of the car.

The amount to be used is selected to satisfy the above requirements, but since there are cases where it is not used, the lower limit is 0 wt % to 0 wt % at most per reaction solution.

The reaction of the present invention can be carried out by a batch method or a continuous method. For example, in the case of a batch method, an aromatic nitro compound, a compound having a phenolic hydroxyl group, and a catalyst are charged into the reaction system, and the temperature is raised. Afterwards, the inside of the reaction system is pressurized to remove carbon oxide, and the reaction can be carried out under stirring. The reaction temperature is usually 10θ to 250°C, preferably 770 to 200°C.
°C and the pressure is usually /~200'i/ad.

Preferably 30~/θθ to 91tr! It is. The reaction time is usually /θ minutes~/! time, preferably /~70
It takes about an hour.

After completion of the reaction, the mixture is separated by an fv-groove such as the palladium catalyst present in the same form, and then the mother liquor is crystallized to form crystals of aromatic carbamate ester f! : Precipitate and collect this through P.

Crystallization is performed by concentrating when using a solvent.
Alternatively, the mother liquor may be cooled as it is.

As with the conventional production of TD, the urethane obtained by reacting MD with a compound having an excess of alcoholic hydroxyl groups has high solubility in nucleated solvents and cannot be separated by crystallization. This is common, and even if a compound with a phenolic hydroxyl group is used as in the present invention, compared to the power of using a compound with an alcoholic hydroxyl group, if there is a large number of phenolic hydroxyl groups, the urethane will be exposed to phenol.
This makes crystallization difficult. However, when the number of phenolic hydroxyl groups is small as in the present invention, urethane crystallization is effective. In addition, in the present invention, the composition of the reaction mother liquor after crystallization is different from that in the conventional case where an excessive amount of a compound having a hydroxyl group is used. The hydroxyl group-containing compound, inert solvent, tertiary amine compound, and other catalyst components remain, and in some cases, an aromatic mononitro compound may remain as a solvent without using an inert solvent. In the present invention, such reaction mother liquor K is F
The solid catalyst component removed by J can also be recycled. In the case of recycling, the entire amount of the mother liquor and the separated catalyst may be used, or it goes without saying that a portion of the mother liquor and the separated catalyst may be further added with the raw material, solvent, and catalyst.

The present invention will be explained below with reference to examples. Example 1/ A zircon-lined induction rotary autoclave with an internal volume/l was charged with 2% Pd/CiJ♂y, V2O, // my(
/ +r+rnol), ire powder 66 tny (/
mmol), quinoline, 2. / , p (/otn
omol), quinoline phosphate/, 3￥ f, (cf'
mmol), nitrobenzene/θ3g (, rgθ
mmo1)%7-1mno, 21.9(2,5'θm
r1ool), ) Ruenj? Prepare me 1.
After washing with 20g/- of N2 λ times, the temperature was raised to 6θ°C, and the reaction solution was taken out while washing. PeL/C was separated by r, and II/-* was analyzed by high-performance liquid chromatography. The conversion of nitrobenzene was 29%, and the phenol urethane of enyl isocyanate was 33 mmol.
It was found that it was generated. Contains acetone wash solution
10/2 of the reaction solution with t,<xy is vacuumed at room temperature32. The mixture was concentrated to 200 g, cooled in a water bath, and the precipitated crystals were treated with P to obtain white crystals. By further boiling the mother liquor to 27.32, white crystals of 3.62 were further obtained. A total of 22 crystals were analyzed by liquid chromatography, and it was found that 2.2 mmol of urethane was crystallized, which corresponded to 26% of the total urethane.

Example 2 - Reactions were carried out on the [bJ strain] except for the conditions shown below. The results are shown in Table-/ along with the conditions.

Table-/Example Ij Nitrobenzene/2F? (,10gjmmol), Phenol 26? (2Fθmmol), toluene 72-, pyridine/IP (i, t 1) IWOl), pyridine hydrochloride 0. The reaction was carried out in the same manner as in Example Solution/, except that 41 f (, F mmol) was used.

The result is the conversion rate of nitrobenzene/? %, urethane raw JBf, amount/'3mrn○1. Using %/33 of the reaction solution (acetone-containing) 6339,
The mixture was concentrated to give crystals of 02.

jl! It moves to j 2,7 f, θ,! /2 crystals were obtained.

In total /! mmol of urethane f was obtained, and the crystallization rate was 6/') based on the total urethane produced.

Ratio example 1/ Nitrobenzene! 'l? (,,2+4'(17m
mol), phenol tata? (10!Ommol
), and the panicles using toluene and 7-talou were reacted in the same manner as in Example K/.

Results Kenitrobenzene conversion rate 39 bulk, urethane cBEi
It was ¥rmmo1. Of the reaction solution (ton arsenide) 2/ and 2, /? 0y was concentrated to 37y to obtain 0.99 crystals, and further 32. Although urethane crystals were reduced up to 2, no urethane crystals were obtained, and urethane was 0.23 mm out of a total of 0.72 mm.
ol, only 2% of the total urethane produced was obtained by crystallization.

Example 16 Zircon-lined rotary autoclave with internal volume/l
c, ;t ”k6 pa/c, 2./y, V2O
,/ (1'/7q(/mmol), li'e
Bladder s s my (/mmol), quinoline 2. /
9 (/6' mmol), quinoline hydrochloride/, 3 tata (/mmol), nitrobenzene/θ
3g (!ri0 +nn+ol), phenol +2ty
(2 and θ mmol), 51 ba of toluene was charged, and after coloring λθ twice with Mi(7-)N, θkg/cfI of CO was injected into 1.5 The reaction was allowed to take place for a period of time.

After cooling thoracotomy, the autoclave was washed with acetone and sent to reaction meJ&, Pd/Ci was separated and P ridges were analyzed by high-speed number body chromatography.

The conversion of nitrobenzene is 2 q%, and the 7-enol urethane (urethane) of phenyl incyanate is 30 m
mo1 was generated and used. This reaction solution 33ty (containing acetone) was diluted to 73 and 2 with Makabe at room temperature and cooled on ice to obtain white crystals of 3F, and this crystal-coated mother liquor was further condensed to 70g. By cooling on ice, white crystals of υ3.72 were obtained. When these white crystals were analyzed by waste body chromatography, it was found that a total of 10 θmmo:t of urethane was obtained. This was 27% of the urethane produced.

Also f# residual nitrobenzene J' in the liquid, 2 nar
rrol, the same phenol was /4t♂mmol.

The total amount of mother liquor recovered in this two-stage crystallization was added to 30% nitrobenzene. !
y(-2x, rmmol) and phenol/2.41
? (/3.2 mmol) and toluene, 27. ．． 2
ml was added, and the Pd/C that had been separated earlier was added and charged into the same autoclave, and the reaction was carried out in the same manner as the first time. The conversion rate of nitrobenzene was 1d' 6%, and urethane was present at /26 mmoh.

3ssy of lachrymal fluid (containing acetone) obtained from Pa10 was concentrated under vacuum at room temperature until 7322, and after cooling with water/2. ? The white crystals were taken from house to house, and the furnace liquid was stirred until 62 days, and after cooling with water, white crystals were obtained at 29 days later. These white crystals 1
'PK was /7 mm01 (Q urethane was obtained. This was achieved with a crystallization rate of 62% based on the urethane in the reaction solution.

vj Permission Applicant: Mitsubishi Kagen Korai Co., Ltd. Agent
Orator, Atsutani - other/names

Claims (2)

[Claims] (1) In a method for producing a urethane compound by reacting an aromatic mononitro compound with a compound containing a phenolic hydroxyl group and carbon monoxide, the phenolic hydroxyl group is made into an equimolar amount with respect to the nitro group, and ■palladium■ Vanadium and/or tertiary butyric amine ■ The reaction is carried out in the presence of a catalyst containing a halogen atom, and after the solid catalyst component is removed from the reaction mixture, the urethane compound is crystallized and separated. Method for manufacturing urethane compound (2) The method according to claim 1, characterized in that the crystallization mother liquor after crystallizing and separating the urethane compound vIJ and the solid catalyst component are recycled to the reaction thread.