JPS5879958A - Production of carbonic ester - Google Patents

Abstract

PURPOSE:The reaction of a formic ester with urea or N-substituted urea is conducted in the presence of a specific catalyst to permit the production of the titled compound used as a starting material for polycarbonate, from low-toxic and easy-to-handle starting materials using a relatively inexpensive catalyst with advantage. CONSTITUTION:The reaction of a formic ester with urea or N-substituted urea is carried out in the presence of a compound of an element in groups Ib, IIa, IIb, IIIb, IVa, IVb, VIa, VIIa, VIII or of an actinide element, and a nitrogen or phosphorus-containing organic compound or an organic compound of an element in groups Ia, at 50-500 deg.C, preferably 100-300 deg.C to give the objective compound. Examples of the catalyst are, copper, magnesium, zinc, boron, zirconium, silicon, chromium, manganese, iron, thorium, monomethylamine, trimethylphosphine and sodium alcoholate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing carbonic esters, and more particularly to a method for producing carbonic esters by reacting formic acid esters with urea or N-substituted urea.

Since carbonate ester is a raw material for polycarbonate, its importance has been recognized as polycarbonate has attracted attention as an excellent plastic.

By the way, conventional methods for producing carbonate esters include a method in which alcohol and phosgene are reacted, a method in which alcohol and carbon monoxide are reacted using a noble metal as a catalyst, and a method in which alcohol and methyl chloroformate are reacted. ing. However, these methods are not industrially satisfactory because the raw materials are highly toxic or require the use of expensive catalysts.

Also, Japanese Patent Application Laid-Open No. 55-151 related to the invention of the present inventors
According to the No. 540 publication, the present invention discloses the production of formic acid esters by using acetates, halides, nitrates, etc. of heavy metals such as copper, zinc, iron, cobalt, and nickel as catalysts or without using catalysts. This invention involves producing carbamic acid and formamide by reacting them with urea, but this method did not yield any carbonate ester.

The present inventors have continued to conduct research in order to find an industrially advantageous and easy method for producing carbonate esters using raw materials with low toxicity and easy reinforcement, and using relatively inexpensive catalysts. On the other hand, while further investigating the reaction between formic acid ester and urea or N-substituted urea, we surprisingly discovered a new finding that carbonic acid ester can be obtained efficiently when a unique catalyst is used. Based on this new knowledge, we have completed the present invention.

That is, in the present invention, formic acid ester and urea or N-substituted urea (1) of periodic table 1b, IIa, IIb, II
Ib, IVab IVb, Vla, VIIa or V
Presence of a compound of a group III element or a compound of an actinide group element (hereinafter referred to as the first component) and (b) a nitrogen-containing organic compound, a phosphorus-containing organic compound, or an organic compound of a group Ia element (hereinafter referred to as the second component) This is a method for producing a carbonate ester, which is characterized by carrying out the reaction below.

The formic acid ester used in the present invention is not particularly limited, but in practice, a formic acid ester represented by the general formula (11HCOOR) is usually used.

In this general formula (1), R represents an alkyl group having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, ryomyl, hexyl, and octyl. It is an alkyl group.

Among these formic acid esters, methyl formate or ethyl formate is practically preferred. In addition to urea, N-substituted ureas are used in the present invention. The N-substituted urea used in the present invention is not particularly limited. In addition, in this general formula (2), R1 to R4 are hydrocarbon groups or hydrogen atoms. Note that R1 to R4 may be the same or different. Examples of the hydrocarbon group include an alkyl group or an aryl group. The alkyl group is usually an alkyl group having 1 to 4 carbon atoms, but from a practical standpoint, methyl group, ethyl group, etc. are preferable. Further, the aryl group includes a phenyl group, a tolyl group, and the like, and a phenyl group is practically preferred. In addition,
Cases in which R1 to R4 are all hydrogen atoms are excluded.

Furthermore, an alkyl group and an aryl group cannot be contained simultaneously in the same molecule. Examples of N-substituted ureas include monoalkylurea, monoarylurea, N,N-dialkylurea, N,N-diarylurea, N,N'-dialylurea, N,N'-diarylurea, N,N , N'-trialkylurea, N, N, N'-triarylurea, N, N
.

N', N'-tetraalkylurea, N, N, N', N'
- Examples include tetraarylurea. Urea and symmetric N-substituted ureas are preferred because they can reduce the complexity of the reaction product. Suitable N-substituted ureas include symmetrical disubstituted ureas such as N,N-dialkylureas such as N,N'-dimethylurea and N,N'diarylureas such as N,N'-diphenylurea. be able to.

In the method of the present invention, the molar ratio of formic acid ester to urea or N-substituted urea (hereinafter both may be referred to as urea etc.) (urea etc.: formic acid ester) is 1:1 or more, which is practically , usually 1:1 to 30, preferably 1:1 to 30, preferably 1:1 to 30.
:2 to 10.

The reaction temperature in the present invention is 50 to 500°C.

When the reaction temperature is lower than 50°C, the reaction rate is slow, and when the reaction temperature is higher than 500°C, there is an increased risk that side reactions such as polymerization and decomposition will occur simultaneously. The preferred reaction temperature is 100-300°C.

The reaction according to the invention can also be carried out under the respective vapor pressures of the urea etc. used and the formic acid esters at their reaction temperatures, ie under autogenous pressure.

Further, the reaction can be carried out in a carbon monoxide atmosphere for the purpose of suppressing the decomposition of the formic acid ester, and for this purpose, carbon monoxide is usually charged at 0 kg/cm 2 G or more prior to the reaction.

In addition, the carbon monoxide partial pressure is 0 kg/cm2G or more,
Usually 0-1000kl? The carbon monoxide partial pressure is preferably 0 to 500 kg/cm2G, since it is impractical to use a higher pressure than necessary. The reaction can also be carried out under an atmosphere of an inert gas such as nitrogen.

In the present invention, a solvent is not necessary, but it is possible to use a solvent such as, for example, an amide, ether, ketone or alcohol. Typical solvents include:
Amides include formamide, N-methylformamide and N,N-dimethylformamide, ketones include acetone and methyl ethyl ketone, ethers include dimethyl ether and diethyl ether, and alcohols include methanol and ethanol.

The reaction in the present invention can be carried out in any of the batch, semi-batch and flow methods.

The catalyst in the present invention contains a first component and a second component.

As the first component of the catalyst used in the present invention, the periodic table (
However, the periodic table is based on Toshizo Chiya, Inorganic Chemistry (New Edition) Volume 1, published by Sangyo Tosho. ) Ib, IIa, IIb, II
Ib, IVa, IVb, VIa, VIIa, VIII
or actinide group elements. Harsh elements are, for example, copper and silver in group Ib, magnesium, calcium and barium in group IIa, zinc and mercury in group Ilb, boron and aluminum in group IIIb, zirconium in group IVa,
The Vb group includes silicon, phosphorus, and lead; the Vla group includes chromium, molybdenum, and tungsten; the VII group includes manganese and rhenium; the ■ group includes iron, cobalt, nickel, and palladium, and the actinide group includes thorium and uranium.

Compounds of these elements are not particularly limited, but include, for example, organic acid salts such as formates, acetates, oxalates and naphthenates, inorganic acid salts such as sulfates, carbonates and nitrates, polyamino acids. These include chelate compounds such as carboxylate and acetylacetone salts, halides, and carbonylate compounds. Mixtures of the compounds of the first component can also be used.

The second component of the catalyst used in the invention is a nitrogen-containing organic compound, a phosphorus-containing organic compound or an organic compound of a group Ia element.

The nitrogen-containing organic compound is not particularly limited, but typical examples include amines such as monomethylamine, dimethylamine, trimethylamine, dimethylethylamine, triethylamine, tri-n-propylamine, tri-iso-propylamine, and tri-n-butylamine, aniline, and alkylaniline. pyridine, pyrrolidine, piperidine, pyrimidine, N-alkyl substituted products thereof, and alkylpyridine.Although there are no particular restrictions on the phosphorus-containing organic compounds, in practice, trivalent phosphorus organic compounds are usually used. used. Representative examples include trialkylphosphines such as trimethylphosphine and tributylphosphine, phosphines with substituted alkyl groups such as tris(aminoamyl)phosphine, triarylphosphines such as triphenylphosphine, and trimethylphosphine and trimethylphosphine. Phosphites of enyl phosphites can be mentioned.

There are no particular limitations on the compounds of Group Ia elements, but for example, organic compounds of sodium and potassium, such as sodium alcoholate and potassium alcoholate, are preferably used. Mixtures of compounds of the second component can also be used.

These catalyst component compounds can be used by being supported on a conventional carrier such as clay, acid clay or activated carbon.

The amount of the first component of the catalyst to be used can be selected within the range of 0.01-100 mgmol per 100 mgmol of urea etc. (hereinafter expressed in mgmol per 100 mgmol of urea etc. unless otherwise specified), but it is economical to use more than necessary. Moreover, if the amount used is small, a sufficient reaction rate cannot be obtained.

The amount of the first component of the catalyst used is preferably 0.02 to 70 Qmol, particularly preferably 0.05 to 50 Qmol.

The amount of the second component of the catalyst used is 100 mgmo such as urea.
0.01 to 100 mgmol per liter (unless otherwise specified, mgmol per 100 mgmol of urea, etc.)
) can be selected from the range of 0.02 to 70 mg
m01 is preferred, and 0.05 to 50 mgmol is particularly preferred.0 In the present invention, in addition to carbonate esters, carbamic acid esters and formamides are co-produced, but these can be separated from each other by a simple means such as distillation. Moreover, both have high utility value, so there is no need to consider them at all.

In other words, carbamate esters are heavily used in the medical field and are also used in large quantities as raw materials for urethane.
Formamides have recently attracted particular attention as not only excellent solvents but also intermediate raw materials in the chemical industry. Formamides also act as a solvent in the reaction of the present invention.

The carbonate ester, carbamate ester, and formamide obtained in the present invention are of the general formula (1) and the general formula (
When the compounds represented by 2) are used, they are represented by the following general formulas (3), (4) and (5), respectively. That is, general formula (3) RO・CO・OR and R and R1 to R4 in these general formulas (3) to (5) are the same as in the above general formulas (1) and (2), respectively. be. Note that when urea is used, in the general formula (4) and general formula (5),
All of R1 to R4 are hydrogen atoms.

In the present invention, the raw materials are all low-toxic and easy-to-handle substances, the catalyst is relatively inexpensive, and the carbonate ester can be easily and industrially obtained, and the carbamate ester is co-produced. and formamides each have high utility value, and the industrial value of the present invention is extremely high.

Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 33 In a Hastelloy C autoclave with an internal volume of 100 cc,
After each predetermined amount of N,N'-dimethylurea, formic acid ester, and catalyst is charged and the lid is closed, the air in the autoclave is replaced with carbon monoxide or nitrogen, or after the replacement, carbon monoxide or nitrogen is heated to a predetermined pressure. It was filled and reacted at a predetermined temperature for a predetermined time. After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed by gas chromatography. The conditions and results are collectively shown in Table 1.

Example 34 N in a Hastelloy C autoclave with an internal volume of 100 cc.
, N'-dimethylurea 111.22 mgmol, methyl formate 334.05 mol, iron acetylacetonate 1.42 mgmol, tributylphosphine 1.8
7 mol and N-methylformamide 76.55
mg mol was added, the lid was placed, and the air inside was replaced with carbon monoxide.

Next, carbon monoxide was charged to 60 kg/cm 2 G, and the reaction was carried out at 175° C. for 1 hour. After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed by gas chromatography. As a result, methyl N-methylcarbamate 80.64mgm
ol, dimethyl carbonate 20, 64 mgmol, % and N-methylformamide 122.07 mgmol were produced, respectively.

Example 35 N in a Hastelloy C autoclave with an internal volume of 100 cc.
, N'-diphenylurea 49.89 mOl, methyl formate, 305.08 mgmol. 1,42 mgmol of iron acetylacetonate) and 1,26 mgmol of triphenylphosphine were charged, the lid was closed, and the air inside was replaced with carbon monoxide. Then, carbon monoxide was charged to 57 kg/cm2G, and the reaction was carried out at 180°C for 4.5 hours. After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed by gas chromatography.

Its M fruit, methyl N-phenylcarbamate 32, 8
4 mgmol, dimethyl carbonate 7, 96 mgmol, formanilide 49, 85 mgmolExample 3
6 N in a Hastelloy C autoclave with an internal volume of 100 cc.
, N'-diphenylurea 49, 47 mgmo
l, methyl formate 152.54 mgmol, iron acetylacetonate) 1.42 mol, triphenylphosphine 1.14 mgmol and acetone 15B,
92 mol was added, the lid was placed, and the air in the contents was replaced with carbon monoxide. Then carbon monoxide was added at 59 kg/c.
It was filled up to m 2 G and reacted at 175° C. for 4.5 hours. After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed by gas chromatography. As a result, methyl N-phenylcarbamate 36.83 mgmol, dimethyl carbonate 7
．． 16 mgmol and 53.2 mgmol of formanilide were produced, respectively.

Example 37 N in a Hastelloy C autoclave with an internal volume of 100 cc.
, N-dimethylurea 111.22 mgmol, methyl formate 334, 72 mgmol, acetic acid steel 2.50
mgmol and triphenylbosphin 2.62m
gmol was added, the lid was closed, and the air inside was replaced with carbon monoxide. Then add 57 kg/cm2 of carbon monoxide.
The reactor was filled up to G and reacted at 180°C for 3 hours. After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed using a gas chromatograph.

As a result, formamide 18, 24 mgmol,
Dimethyl carbonate 5.38 mgmol, methyl carbamate 67.54 mgmol and N,N-dimethylformamide 74.63 mg
mol were produced respectively.

Example 38 N in a Hastelloy C autoclave with an internal volume of 100 cc.
, N-dimethylurea (111.22 mgmol), isopropyl formate (335.68 mgmol), iron acetylacetonate (1.42 mgmol), and tributylphosphine (1.39 mgmol), and the reactor was covered with a lid and the air inside was replaced with carbon monoxide. Then 175℃
The mixture was allowed to react for 2 hours.

After cooling, the gas in the autoclave was purged to return to normal pressure, and the reaction product was taken out and analyzed using a gas chromatograph. As a result, formamide 19.87mgm
ol, diisopropyl carbonate 5.63 mgmol, isopropyl rubamate 70. 24 mgmol and N,N-dimethylformamide 72.86mgmol
l were generated respectively.

Examples 39 to 45 After charging a predetermined amount of urea, formic acid ester, and catalyst into a Hastelloy C autoclave with an internal volume of 100 cc and closing the lid, the air in the autoclave was replaced with carbon monoxide, or after the replacement, monoxide was removed. It was filled with carbon to a predetermined pressure and reacted at a predetermined temperature for a predetermined time. After cooling, the autoclave was purged of gas to return to normal pressure, and the reaction product was taken out and analyzed using a gas chromatograph. The conditions and results are collectively shown in Table 2.

Claims (1)

[Claims] Formic acid ester and urea or N-substituted urea, (a) periodic table Ib, IIa, IIb, IIIb, IVa, IV
(b) a compound of a group VIa, VIIa or VIII group element or a compound of an actinide group element; and (b) a nitrogen-containing organic compound, a phosphorus-containing organic compound or a framed compound of a group Ia element. Method for producing carbonate ester.