KR20110133712A - Method for preparing formamide compound from amine compound using ionic liquid catalyst - Google Patents

Abstract

The present invention relates to a process for the production of a formamide compound by reacting an amine compound with carbon monoxide in the presence of an ionic liquid catalyst having a tellurite anion (TeO ₃ ^- ). According to the production method of the present invention, a wide variety of formamide compounds can be produced with high yield and selectivity, and the stability of the catalyst to moisture is high, enabling the catalyst to be reused.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a formamide compound from an amine compound using an ionic liquid catalyst,

The present invention relates to a process for preparing a formamide compound from an amine compound using an ionic liquid catalyst, and more particularly to a process for preparing an amine compound by reacting an amine compound with carbon monoxide in the presence of an ionic liquid catalyst having a tellurite anion (TeO ₃ ^- ) / RTI > compounds. ≪ Desc / Clms Page number 2 >

In general, formamide compounds are chemically possessed of two functional groups and have high polarity, and thus are widely used as reaction solvents, extracting agents, fine chemical intermediates, and antioxidants in the rubber industry. Especially recently, antioxidants, intermediates of medicinal substances and insecticides (Ullmann's encyclopedia of industrial chemistry, 5th, Vol. A 12, pp 1-12).

The formamide compound is industrially produced by reacting an amine compound with carbon monoxide in the presence of a NaOCH ₃ catalyst. However, this method is limited to amine compounds having a simple structure such as ammonia, methylamine and dimethylamine. In the case of an amine compound or an aromatic amine compound having a steric hindrance, the method has a limitation in that it can not be used because of its catalytic activity. In addition, since this method uses water-sensitive NaOCH ₃ as a catalyst, it has a disadvantage that it needs to thoroughly control the moisture content of the raw material, and is almost impossible to be reused and neutralized by acid after the reaction (Jpn. Kokai Tokkyo Koho, 2002128747, 09 May 2002, 2002-128747).

As another production method, there is a method of producing a formamide compound by reacting an amine compound with methyl formate or ethyl formate under a Lewis acid catalyst, as disclosed in a reference [Tetrahedron Letters, v 46, p 7963 (2005) There is a problem that methyl formate or ethyl formate, which is expensive compared to carbon monoxide, must be used as a raw material.

U.S. Patent No. 6441234 discloses a method for preparing a formamide compound by reacting carbon monoxide with an amine compound using NaN (CHO) ₂ as a catalyst instead of NaOCH ₃ , which is reactive but water-sensitive and thus is not reusable. However, this method is limited to the synthesis of formamide and methylformamide, and the cost of the catalyst is high.

The inventors of the present invention have conducted intensive studies in order to solve problems such as limitation of reuse due to instability of catalysts, use of expensive reaction materials, low selectivity and yield, which are problems in conventional methods for preparing various formamide compounds, It has been found that when an amine compound and carbon monoxide are reacted in the presence of an ionic liquid catalyst having a tellurite anion, the formamide compound can be produced at a high selectivity and yield regardless of the structure of the raw material amine compound.

Accordingly, it is an object of the present invention to provide a process for preparing various types of formamide compounds with high yield and high selectivity.

The present invention relates to a process for preparing a formamide compound characterized in that an amine compound is reacted with carbon monoxide (CO) in the presence of an ionic liquid catalyst having a tellurite anion represented by the following general formula (1) or (2)

[Chemical Formula 1]

(2)

R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or a phenyl group.

The amine compound used in the production method of the present invention includes ammonia, a primary amine compound represented by the following general formula (3), a secondary amine compound represented by the following general formula (4) and a nitrogen cyclic amine compound represented by the following general formula Such as methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine, n-hexylamine, cyclohexylamine, dimethylamine, diethylamine, dibutylamine, pyrrolidine, But are not limited to, furan, piperidine, aniline, and the like.

(3)

R ⁵ NH ₂

[Chemical Formula 4]

R ⁶ ₂ NH

[Chemical Formula 5]

Wherein R ⁵ and R ⁶ are each independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 1 to 6 carbon atoms or a phenyl group,

X is CH ₂ , O or S,

n and m are each independently an integer of 1 to 2;

According to the preparation method of the present invention, various amine compounds are carbonylated by carbon monoxide to form various formamide compounds. Specifically, the amine compounds represented by the above formulas (3), (4) and (5) react with carbon monoxide as shown in the following reaction formulas (1) to (3) to convert to the corresponding formamide compounds.

[Reaction Scheme 1]

[Reaction Scheme 2]

[Reaction Scheme 3]

Since the purity of carbon monoxide used as a starting material in the production process of the present invention does not greatly affect the reaction, an industrially produced product can be used without further purification.

The ionic liquid catalyst having a tellurite anion used in the production method of the present invention may be, for example, 1-butyl-3-methylimidazolium tellurite, 1-ethyl-3-methylimidazolium tellurite, -Dimethylimidazolium tellurite, N-butyl-N-methylpyrrolidinium tellurite, N-ethyl-N-methylpyrrolidinium tellurite, N, N-dimethylpyrrolidinium tellurite, It is not.

The ionic liquid catalyst having a tellurite anion according to the present invention has high stability against moisture and can be reused. Therefore, it is possible to solve the problem of water vulnerability and reuse which is a problem of the conventional alkali metal alkoxide catalyst, Carbon monoxide can be used as a raw material in place of the expensive alkylformate commonly used in the process of the present invention.

In the present invention, the ionic liquid catalyst can be used in an amount of preferably 0.005 to 0.1 mol, more preferably 0.01 to 0.1 mol, based on 1 mol of the amine compound. When the amount is less than 0.005 mol, the reaction rate is excessively slow When the molar ratio is more than 0.1, the reaction rate and selectivity are not improved any more, so there is no economic benefit.

The reaction for preparing the formamide compound according to the present invention is preferably carried out in a temperature range of 80 to 170 ° C. If the reaction temperature is lower than 80 ° C., the reaction rate becomes too slow. If the reaction temperature is higher than 170 ° C., There is a problem that the reaction selectivity is lowered by decomposition of the amide compound to promote the formation of by-products.

The reaction pressure of the carbon monoxide is preferably in the range of 100 to 1,000 psi. When the reaction pressure is less than 100 psi, the reaction rate tends to be slightly slowed. When the reaction pressure is more than 1,000 psi, There is no promotion effect.

The reaction is preferably carried out using a protic polar solvent having a proton capable of increasing the nucleophilicity of the amine compound as a reaction solvent. Specifically, one or a mixture of two or more selected from the group consisting of methanol, ethanol, n-propanol, isopropanol and n-butanol can be used. The amount of the polar solvent is preferably in the range of 50 to 500% by weight based on the amine compound. If the amount of the polar solvent is less than 50% by weight, control of the calorific value is not sufficient and the production of by-products is increased. While there is no increase in speed, there is no economic benefit because excessive solvent is used.

According to the production method of the present invention, it is possible to easily and economically produce a wide variety of formamide compounds such as formamide of aromatic and nitrogen rings which can form amide compounds with high yield and selectivity and which are difficult to produce by conventional methods However, since the stability of the catalyst to moisture is high, the catalyst can be reused.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are for illustrative purpose only and that the scope of the present invention is not limited to these embodiments.

Example 1 Synthesis of Ionic Liquid Catalyst with Tellurite Anion

To a 100 mL single-necked flask was charged 20 mL of methanol, 3.19 g (20 mmol) of tellurium dioxide, 2.77 g (20 mmol) of potassium carbonate and 6.98 g (40 mmol) of 1-butyl-3-methylimidazolium chloride, For 12 hours. After the reaction, the methanol was removed under vacuum, dichloromethane was added to the remaining solid mixture to extract the product, and the dichloromethane was again removed under vacuum to obtain the final product, 1-butyl-3-methylimidazolium tellurite ([BMIm] ₂ TeO ₃ ) (yield: 87%).

An ionic liquid catalyst having the tellurite anion used in Examples 34 to 38 was obtained in the same manner as above.

Example 2: Preparation of formamide compound

100 mL with cyclohexylamine 3.27 g (33 mmol) and a solvent into an autoclave charged with methanol (10 mL), the _{[BMIm] 2 TeO 3 0.104 g} (0.33 mmol) prepared in Example 1 as a catalyst and a 300 psi carbon monoxide , The temperature was raised to 150 ° C, the pressure of the carbon monoxide was adjusted to 500 psi, and the reaction was allowed to proceed for 4 hours. After the reaction was completed, the reactor was cooled at room temperature, and the liquid product remaining after removal of the catalyst was analyzed by gas-liquid chromatography. The yield and selectivity of the product, cyclohexylformamide, were 91.7% and 96.2%, respectively, and the yield and selectivity were calculated by the following formula.

Yield (%) of cyclohexylformamide =

Selectivity (%) of cyclohexylformamide =

Examples 3 to 17: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2, except that the type of the amine compound was changed. The results are shown in Table 1 below.

Example Amine compound yield(%) Selectivity (%) 3 Methylamine 95.6 98.3 4 Ethylamine 96.7 98.4 5 n-propylamine 97.3 99.2 6 Isopropylamine 79.4 94.6 7 n -Butylamine 99.0 99.6 8 t -Butylamine 35.5 98.2 9 n -hexylamine 99.4 99.6 10 Dimethylamine 80.1 96.9 11 Diethylamine 64.3 95.7 12 Dibutylamine 42.3 97.7 13 Pyrrolidine 99.2 98.2 14 Azetidine 99.3 98.5 15 Morpholine 63.9 97.9 16 Piperidine 98.3 99.2 17 aniline 47.6 96.4

Examples 18 to 22: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2 except that the reaction temperature was changed. The results are shown in Table 2 below.

Example Reaction temperature (캜) yield(%) Selectivity (%) 18 80 31.4 98.9 19 110 63.8 97.5 20 140 88.8 96.8 21 160 89.9 91.4 22 170 81.3 89.7

Examples 23 to 28: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2, except that the pressure of carbon monoxide was changed. The results are shown in Table 3 below.

Example Pressure of carbon monoxide (psi) yield(%) Selectivity (%) 23 100 52.6 94.2 24 300 80.7 96.3 25 400 86.2 96.1 26 600 93.1 96.8 27 800 93.6 97.5 28 1,000 93.9 97.6

Examples 29 to 33: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2 except that the molar ratio of [BMIm] ₂ TeO ₃ / amine was changed. The results are shown in Table 4 below.

Example Catalyst / amine (molar ratio) yield(%) Selectivity (%) 29 0.005 53.6 91.4 30 0.015 91.2 97.1 31 0.02 94.1 97.9 32 0.05 95.2 98.4 33 0.1 95.8 99.1

Examples 34 to 38: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2 except that the molar ratio of catalyst / amine was fixed at 0.01 and the kind of catalyst was changed. The results are shown in Table 5 below.

Example catalyst yield(%) Selectivity (%) 34 [EMIm] ₂ TeO ₃ 84.6 95.8 35 [DMIm] ₂ TeO ₃ 82.6 96.3 36 [BMPyrr] ₂ TeO ₃ 77.4 96.1 37 [EMPyrr] ₂ TeO ₃ 75.1 96.8 38 [DMPyrr] ₂ TeO ₃ 71.4 95.7

[EMIm] ₂ TeO ₃ : 1-ethyl-3-methylimidazolium tellurite

[DMIm] ₂ TeO ₃ : 1,3-dimethylimidazolium tellurite

[BMPyrr] ₂ TeO ₃ : N-butyl-N-methylpyrrolidinium tellurite

[EMPyrr] ₂ TeO ₃ : N-ethyl-N-methylpyrrolidinium tellurite

[DMPyrr] ₂ TeO ₃ : N, N-dimethylpyrrolidinium tellurite

Examples 39 to 44: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2, except that the amount of the solvent was fixed to 240% by weight of the amine and the kind of the solvent was changed. The results are shown in Table 6 below.

Example menstruum yield(%) Selectivity (%) 39 ethanol 78.1 95.9 40 n-propanol 78.1 95.9 41 Isopropanol 71.8 96.7 42 n-butanol 61.8 95.9 43 t-Butanol 58.6 94.3 44 n-hexanol 42.5 94.1

Examples 45 to 48: Preparation of formamide compound

The reaction was carried out in the same manner as in Example 2, except that the amount of the solvent to be used was changed. The results are shown in Table 7 below.

Example Solvent / Amine (wt.%) yield(%) Selectivity (%) 45 50 71.3 87.1 46 100 87.1 90.5 47 350 88.8 96.8 48 500 88.4 98.1

Claims (9)

A process for producing a formamide compound, which comprises reacting an amine compound with carbon monoxide (CO) in the presence of an ionic liquid catalyst having a tellurite anion represented by the following formula (1) or (2)
[Chemical Formula 1]

(2)

R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or a phenyl group. The process according to claim 1, wherein the amine compound is ammonia, a primary amine compound represented by the following formula (3), a secondary amine compound represented by the following formula (4), or a nitrogen cyclic amine compound represented by the following formula
(3)
R ⁵ NH ₂
[Chemical Formula 4]
R ⁶ ₂ NH
[Chemical Formula 5]

Wherein R ⁵ and R ⁶ are each independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 1 to 6 carbon atoms or a phenyl group,
X is CH ₂ , O or S,
n and m are each independently an integer of 1 to 2; The ionic liquid catalyst according to claim 1 or 2, wherein the ionic liquid catalyst having a tellurite anion is selected from the group consisting of 1-butyl-3-methylimidazolium tellurite, 1-ethyl- N-methyl-pyrrolidinium tellurite, N-ethyl-N-methylpyrrolidinium tellurite or N, N-dimethylpyrrolidinium tellurite. . 3. The process according to claim 1 or 2, wherein the ionic liquid catalyst having a tellurite anion is used in an amount of 0.005 to 0.1 mol based on 1 mol of the amine compound. The process according to claim 1 or 2, wherein the reaction is carried out at a temperature ranging from 80 to 170 ° C. The method according to claim 1 or 2, wherein the carbon monoxide is used in a pressure range of 100 to 1,000 psi. 3. The process according to claim 1 or 2, wherein the reaction is carried out using a polar solvent having a proton as a reaction solvent. The production method according to claim 7, wherein the polar solvent having a proton is one or a mixture of two or more selected from the group consisting of methanol, ethanol, n-propanol, isopropanol and n-butanol. The production method according to claim 7, wherein the polar solvent having a proton is used in an amount of 50 to 500% by weight based on the amine compound.