KR20080054058A - Novel bi-functional ionic liquids and the preparation method thereof - Google Patents

Abstract

Bi-functional ionic liquid is provided to modify the surface of silica easily, so that the surface modified silica is useful for immobilization of metal catalyst, and development of supported ionic liquid phase catalyst system, wherein ionic liquid adsorbed is not melted, thereby recovering and reusing metal catalyst. The ionic liquid with bi-functional group of imidazole salt structure containing both of trialkoxysilyl group and urea group is represented by the formula(1), wherein R^1 is C1-C4 alkyl group, R^2, R^3 and R^4 are each independently H or C1-C6 alkyl group; R^5 is H, C1-C16 alkyl group or aryl group; X is BF4, PF6, SbF6, NO3, C1O4, OSO2CF3 or N(SO2CF3)2; and n and m are each independently an integer from 1 to 6. A method for preparing the bi-functional ionic liquid represented by the formula(1) comprises the steps of: reacting amino alkyl imidazole, wherein R2, R3 and R4 in the 2, 4, 5 sites are substituted with isocyatate(R^5-N=C=O) to prepare compounds(II); introducing a trialkoxysilyl group into the compounds(II) to prepare compounds(III); and substituting Y of compounds(III) by X to prepare imidazole salt containing both of trialkoxysilyl group and urea group.

Description

Novel bi-functional ionic liquids and the preparation method

The present invention relates to a new ionic liquid having a double functional group and a method for producing the same.

In contrast to ionic salts or salt compounds consisting of metal cations and nonmetal anions, such as salts, which typically melt at high temperatures above 800 ° C, salts or salt compounds with melting points at temperatures below 100 ° C may be used as ionic liquids. ILs), and in particular, ionic liquids that exist as liquids at room temperature are called room temperature ionic liquids (RTILs). The ionic liquid is an organic salt composed of an organic cation and an anion. The cations include imidazolium, alkylpyridinium, quaternary ammonium and quaternary phosphonium, and NO is an anion. _{^{3 -, BF 4 -, AlCl}} 4 -, Al 2 Cl 7 -, AcO -, PF 6 -, TfO - (trifluoromethanesufonate, CF 3 SO 3 -), Tf 2 N - (bistrifluoromethanesulfonylamide, (CF 3 SO 2) 2 and the like ^{_{- N), CH 3 CH (}} OH) CO 2 - (L-lactate), and SbF. Combinations of various cations and anions are possible, so over 1000 ionic liquids are known to date.

In general, ionic liquids are compounds that are non-volatile, non-flammable, high ionic conductivity, as well as thermally very stable. Physical properties such as hydrophilicity, hydrophobicity and melting point of these ionic liquids are sometimes referred to as designer solvents because they can be adjusted according to the choice of substituents and anions substituted on the nitrogen atom of the imidazole ring. As described above, ionic liquids capable of controlling physical properties, particularly ionic liquids having imidazole cations, have recently attracted much attention as environmentally friendly solvents that can replace organic solvents used in conventional chemical reactions. Ionic liquids are also used in a variety of applications such as electrochemical electrolytes and liquid extraction solvents, as well as separation, recovery and reuse of metal catalysts. [(A) Keim, W .; Wasserscheid, P. Angew . Chem ., Int . Ed . 2000 , 39 , 3772 .; (b) Ionic Liquids in Synthesis Wasserscheid, P .; Welton, T., Eds. Wiley-VCH Verlag, Weinheim, 2003 .; (c) Ionic Liquids : Industrial Applications for Green Chemistry Roger, RD; Seddon, KR Eds, ACS Symposium Series 818, American Chemical Society, Washing DC. 2002 .; (d) Bonhte, P .; Dias, A.-P .; Papageorgiou, N .; Kalyana sundaram, K .; Grtzel, M. Inorg . Chem . 1996 , 35 , 1168 .; (e) Vieer, AE; Reichert, WM; Swatloski, RP; Willauer, HD; Huddleston, JG; Rogers, RD Ionic Liquids : Industrial Applications for Green Chemistry Roger, RD; Seddon, KR Eds, ACS Symposium Series 818, American Chemical Society, Washing DC. 2002. 289-308; (f) Seddon, KR; Stark, A. Torres, M.-J. In clean Solvents : Alternative media for Chemical Reactions and Processing Abraham, MA; Moens, L. Eds, ACS Symposium Series 819, American Chemical Society, Washing DC. 2002. 34-49].

Recently, researches for controlling physical properties of solid surfaces such as silica, including nanomaterials such as nanoparticles and carbon nanotubes, etc. have been actively conducted using unique physicochemical properties of ionic liquids. Such research requires a new ionic liquid containing functional groups such as sulfur and amines, unlike conventional ionic liquids. In particular, the modification of silica solid surfaces with ionic liquids is very important in the development of new materials for the recovery and reuse of metal catalysts. Silica surface-modified with an ionic liquid is used to shape the supported ionic liquid phase (hereinafter abbreviated as SILP) catalysis system. The SIPL catalysis system is a new catalyst immobilization technology that minimizes the use of ionic liquids and increases the efficiency of catalyst recovery and reuse by adsorbing ionic liquids and metal catalysts containing no functional groups on the surface modified silica with ionic liquids. However, the limitation of the SILP catalysis system developed so far has the disadvantage that the adsorbed ionic liquid melts upon separation of the reaction product.

Accordingly, the present inventors are studying a material that enables more efficient and efficient metal catalyst recovery and reuse due to the development of an efficient SIPL catalyst system in which the adsorbed ionic liquid does not melt. The present invention has been completed by developing a new double functional ionic liquid having a urea group with easy group and hydrogen bonding.

It is an object of the present invention to provide a new ionic liquid having a structure of an imidazole salt comprising an alkoxysilyl group and an urea group at the same time.

Another object of the present invention is to provide a method for preparing a new ionic liquid having a structure of an imidazole salt containing an alkoxysilyl group and a urea functional group at the same time.

In order to achieve the above object, the present invention provides a new ionic liquid having a double functional group containing an alkoxysilyl group and a urea group at the same time.

The present invention also provides a method for producing a new ionic liquid having a structure of an imidazole salt containing an alkoxysilyl group and a urea functional group at the same time.

Hereinafter, the present invention will be described in detail.

The present invention provides a new ionic liquid having a double functional group of an imidazole salt structure simultaneously containing a trialkoxysilyl group and a urea group represented by the following formula (1).

Where

R ₁ is a C ₁ to C ₄ alkyl group,

R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ ,

R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups,

X is any one selected from the group consisting of BF ₄ , PF ₆ , SbF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ ,

n and m are each independently an integer from 1 to 10.

Preferably, R ₁ is an ethyl group,

R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group,

R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group,

X is any one selected from the group consisting of BF ₄ , PF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ ,

n and m are each independently an integer from 1 to 6.

Preferred imidazolium derivatives of the general formula (1) comprising a trialkoxysilyl group and a urea group of the present invention are as follows.

1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate;

1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate;

1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide;

1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate;

1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate;

1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide;

1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate;

1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate; or

1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide.

Intermediate compounds of the ionic liquid having a structure of an imidazole salt containing a trialkoxysilyl group and a urea group of the present invention are represented by the following formulas (2) to (3).

In Chemical Formula 2,

R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ ,

R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups,

m is an integer of 1 to 10 independently of each other.

Preferably, R ₁ is an ethyl group,

R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group,

R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group,

m is independently an integer of 1-6.

Preferred intermediate compound (II) of formula (2) having the structure of imidazole salt comprising urea group of the present invention is as follows.

1- [3- (N-aminoethylcarbonyl)] aminopropylimidazole;

1- [3- (N-aminopropylcarbonyl)] aminopropylimidazole; or

1- [3- (N-aminobutylcarbonyl)] aminopropylimidazole.

In Chemical Formula 3,

R ₁ is a C ₁ to C ₄ alkyl group,

R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ ,

R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups,

Y is any one selected from the group consisting of Cl, Br and I,

n and m are each independently an integer from 1 to 10.

Preferably, R ₁ is an ethyl group,

R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group,

R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group,

Y is any one selected from the group consisting of Cl, Br and I,

n and m are each independently an integer from 1 to 6.

Preferred intermediate compound (III) of the general formula (3) having a structure of imidazole salt containing a trialkoxysilyl group and urea group of the present invention is as follows.

1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride;

1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride; or

1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride.

The present invention also provides a method for producing a new ionic liquid having a structure of an imidazole salt containing an alkoxysilyl group and a urea functional group at the same time.

Specifically, the method for preparing an ionic liquid having a structure of an imidazole salt according to the present invention, as shown in Scheme 1 below, R ² , R ^{3 in} positions ² , ⁴ , ⁵ And R ⁴ Preparing a compound (II) by reacting the substituted amino alkyl imidazole with the compound isocyanate (R ⁵ -N = C═O) (step 1); Preparing a compound (III) by introducing a trialkoxysilyl group into the compound (II) prepared in step 1 (step 2); And replacing the Y of the compound (III) prepared in step 2 with X to produce an imidazole salt comprising a trialkoxysilyl group and a urea group (step 3).

In the above scheme,

R ₁ is a C ₁ to C ₄ alkyl group,

R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ ,

R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups,

X is any one selected from the group consisting of BF ₄ , PF ₆ , SbF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ ,

Y is any one selected from the group consisting of Cl, Br and I,

n and m are each independently an integer from 1 to 10.

Hereinafter, the manufacturing method of the present invention will be described step by step.

Step 1, as shown in Scheme 1, R ² , R ^{3 in} positions ² , ^4, And dissolving an amino alkyl imidazole substituted with R ⁴ and an equivalent of isocyanate (R ⁵ -N = C = O) in dichloromethane, followed by stirring at room temperature for 5 hours to prepare urea compound (II). .

In Step 2, as shown in Scheme 1, the urea compound (II) prepared in Step 1 and the equivalent of the trialkoxysilyl compound are dissolved in acetonitrile, and heated and refluxed for 12 hours to form an imidazolium compound (III). ) Step.

In step 3, as shown in Scheme 1, the imidazolium compound (III) prepared in step 2 is substituted with Y by X using an excess of MX to simultaneously include a trialkoxysilyl group and a urea group. It is the step of preparing a sol salt. In this case, M of MX is an alkali metal of Na, K or Li, X is from the group consisting of BF ₄ , PF ₆ , SbF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ It is either one selected.

Since the ionic liquid of the present invention has a structure of an imidazole salt containing a trialkoxysilyl group and a urea group at the same time, it is easy to modify the nanosilica surface.

In addition, ionic liquids modified with silica can be applied to supported ionic liquid phase (SILP) catalytic reaction systems. The ionic liquid modified on the silica used as a catalyst is easy to recover after the reaction, and does not melt well from the silica upon separation. Therefore, it can be used repeatedly.

Suzuki reaction for carbon-carbon bonds was carried out using a silica-palladium catalyst modified with an ionic liquid having a double functional group according to the present invention, and the reaction yield was over 90%. The palladium metal catalyst immobilized on the silica was not only recoverable by filtration but also maintained its catalytic efficiency even after repeated use, so that it was easy to recover and reuse the silica-metal catalyst modified with an ionic liquid having a double functional group. Could be (see Table 1 ).

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the content of the present invention is not limited by the following Examples.

Example 1 Preparation of Double Functional Ionic Liquid

Step 1. Of ureimidazole  Produce

1-1. 1- [3- (N- Aminoethylcarbonyl )] Of aminopropylimidazole  Produce

After dissolving 1- (3-aminopropyl) imidazole (100 mmol) and equivalents of ethylisocyanate in dichloromethane, the reaction mixture was stirred at room temperature for 5 hours. After the completion of the reaction, the solvent was removed by distillation under reduced pressure to obtain 1- [3- (N-aminoethylcarbonyl)] aminopropylimidazole (II-98%, 19.2 g).

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 7.39 (s, 1H), 6.92 (s, 1H), 6.87 (s, 1H), 6.09 (bs, 1H), 5.61 (bs, 1H), 3.91 ( t, J = 7.5 Hz, 2H), 3.09 (m, 4H), 1.85 (m, 2H), 1.0 (t, J = 7.5 Hz, 3H);

¹³ C-NMR (63 MHz, CDCl ₃ ) δ: 159.1, 136.9, 128.8, 119.0, 44.1, 36.5, 34.6, 31.7, 15.3.

1-2. 1- [3- (N- Aminopropylcarbonyl )] Of aminopropylimidazole  Produce

After dissolving 1- (3-aminopropyl) imidazole (100 mmol) and the equivalent of propyl isocyanate in dichloromethane, the reaction mixture was stirred at room temperature for 5 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure to obtain 1- [3- (N-aminopropylcarbonyl)] aminopropylimidazole (II-98%, 21.1 g) was obtained.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 7.46 (s, 1H), 7.01 (s, 1H), 6.96 (s, 1H), 5.88 (bs, 1H), 5.48 (bs, 1H), 4.00 ( t, J = 7.5 Hz, 2H), 3.12 (m, 4H), 1.94 (m, 2H), 1.49 (m, 2H), 0.88 (t, J = 7.5 Hz, 3H);

¹³ C NMR (63 MHz, CDCl ₃ ) δ: 159.1, 137.0, 129.0, 119.0, 44.3, 41.8, 36.7, 31.7, 23.4, 11.2.

1-3. 1- [3- (N- Aminobutylcarbonyl )] Of aminopropylimidazole  Produce

After dissolving 1- (3-aminopropyl) imidazole (100 mmol) and the equivalent of butyl isocyanate in dichloromethane, the reaction mixture was stirred at room temperature for 5 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure to obtain 1- [3- (N-aminobutylcarbonyl)] aminopropylimidazole (II-98%, 22.4 g) was obtained.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 7.49 (s, 1H), 7.00 (s, 1H), 6.97 (s, 1H), 5.80 (bs, 1H), 5.40 (bs, 1H), 4.00 ( t, J = 7.5 Hz, 2H), 3.14 (m, 4H), 1.93 (m, 2H), 1.49 (m, 2H), 1.32 (m, 2H), 0.89 (t, J = 7.5 Hz, 3H);

¹³ C-NMR (63 MHz, CDCl ₃ ) δ: 157.6, 135.3, 127.2, 117.4, 42.6, 38.0, 34.9, 30.6, 30.2, 18.2, 12.0.

Step 2. Trialkoxysilyl - Urea-imidazolium  Produce

2-1. 1- [3- (N- Aminopropylcarbonyl )] Aminopropyl-3- [3- ( Triethoxysilyl )] Propylimidazolium  Preparation of Chloride

1- [3- (N-aminopropylcarbonyl)] aminopropylimidazole (0.247 mmol) prepared in Example 1-2 and an equivalent amount of triethoxysilyl propyl chloride for 12 hours in an acetonitrile solvent Heated to reflux. After the completion of the reaction, the solvent was removed by distillation under reduced pressure to obtain 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride (III-99% , 0.11 g) was obtained.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 10.42 (s, 1H), 7.87 (s, 1H), 7.35 (s, 1H), 5.92 (bs, 1H), 5.64 (bs, 1H), 4.43 ( t, J = 7.2 Hz, 2H), 4.25 (t, J = 7.5 Hz, 2H), 3.74 (q, J = 7.2 Hz, 6H), 3.11 (m, 4H), 2.11 (m, 2H), 1.94 ( m, 4H), 1.49 (m, 2H), 1. 15 (t, J = 7.2 Hz, 9H), 0.88 (t, J = 7.5 Hz, 3H);

¹³ C-NMR (63 MHz, CDCl ₃ ) δ: 159.1, 137.1, 122.9, 121.4, 78.7, 58.3, 51.4, 46.9, 36.3, 30.4, 28.1, 24.0, 23.4, 11.2, 6.8.

Step 3. Trialkoxysilyl - Ureaimidazole  Preparation of the compound

3-1. 1- [3- (N- Aminopropylcarbonyl )] Aminopropyl-3- [3- ( Triethoxysilyl )] Propylimidazolium Of hexafluorophosphate  Produce

3 equivalents of 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride (0.22 mmol) prepared in Example 2-1. Sodium hexafluorophosphate (NaPF ₆ ) was stirred for 24 hours at room temperature under acetone solvent. After the reaction was completed, sodium chloride, which was a solid precipitate, was filtered off. After filtration, the filtrate was distilled under reduced pressure to give chloride anion PF _6. 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate (I-99%, 0.12 g) Got.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 10.21 (s, 1H), 7.70 (s, 1H), 7.30 (s, 1H), 5.92 (bs, 1H), 5.64 (bs, 1H), 4.43 ( t, J = 7.2 Hz, 2H), 4.25 (t, J = 7.5 Hz, 2H), 3.74 (q, J = 7.2 Hz, 6H), 3.11 (m, 4H), 2.11 (m, 2H), 1.94 ( m, 4H), 1.49 (m, 2H), 1. 15 (t, J = 7.2 Hz, 9H), 0.88 (t, J = 7.5 Hz, 3H).

3-2. 1- [3- (N- Aminopropylcarbonyl )] Aminopropyl-3- [3- ( Triethoxysilyl )] Propylimidazolium Tetrafluoroborate  Produce

3 equivalents of 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride (0.22 mmol) prepared in Example 2-1. Sodium tetrafluoroborate (NaBF ₄ ) was stirred at room temperature under acetone solvent for 24 hours. After completion of the reaction, the solid precipitate sodium chloride was filtered off. After filtration, the filtrate was distilled under reduced pressure to replace the chloride anion with BF ₄ anion to yield 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimide. Zolium tetrafluoroborate (I-99%, 0.11 g) was obtained.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 10.01 (s, 1H), 7.77 (s, 1H), 7.45 (s, 1H), 5.92 (bs, 1H), 5.64 (bs, 1H), 4.43 ( t, J = 7.2 Hz, 2H), 4.25 (t, J = 7.5 Hz, 2H), 3.74 (q, J = 7.2 Hz, 6H), 3.11 (m, 4H), 2.11 (m, 2H), 1.94 ( m, 4H), 1.49 (m, 2H), 1. 15 (t, J = 7.2 Hz, 9H), 0.88 (t, J = 7.5 Hz, 3H).

3-3. 1- [3- (N- Aminopropylcarbonyl )] Aminopropyl-3- [3- ( Triethoxysilyl )] Propylimidazolium Of bistrifluoromethanesulfonylamide  Produce

3 equivalents of 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride (0.22 mmol) prepared in Example 2-1. Lithium bistrifluoromethanesulfonylamide (LiN (SO ₂ CF ₃ ) ₂ ) was stirred at room temperature under acetone solvent for 24 hours. After completion of the reaction, the solid precipitate sodium chloride was filtered off. After filtration, the filtrate was distilled under reduced pressure to replace the chloride anion with NTf ₂ anion to yield 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimide. Zolium bistrifluoromethanesulfonylamide (I-99%, 0.13 g) was obtained.

¹ H-NMR (250 MHz, CDCl ₃ ) δ: 10.21 (s, 1H), 7.67 (s, 1H), 7.60 (s, 1H), 5.92 (bs, 1H), 5.64 (bs, 1H), 4.43 ( t, J = 7.2 Hz, 2H), 4.25 (t, J = 7.5 Hz, 2H), 3.74 (q, J = 7.2 Hz, 6H), 3.11 (m, 4H), 2.11 (m, 2H), 1.94 ( m, 4H), 1.49 (m, 2H), 1. 15 (t, J = 7.2 Hz, 9H), 0.88 (t, J = 7.5 Hz, 3H).

Experimental Example 1 Surface Modification of Spherical Nanosilica Using Ionic Liquid

1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide synthesized in Example 3-3 ( 0.1 g) and spherical silica having a diameter of 200 nm were mixed in a 1: 1 weight ratio to prepare a chloroform solution having a 1 M concentration. After the chloroform solution was heated to reflux for 24 hours, the silica was filtered under reduced pressure. The solid silica was washed with dichloromethane and ethanol several times and dried under reduced pressure.

Elemental analysis yielded spherical nanosilica in which the imidazole salt containing 20 mmol of urea functionality per gram of silica was modified on the silica surface.

Experimental Example 2 Immobilization of a Metal Catalyst Using Modified Spherical Nanosilica

Surface-modified with 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide prepared in Experiment 1 200 nm diameter spherical silica (0.1 g, content of urea functionality: 20 mmol / g) and the equivalent amount of palladium acetate [Pd (OAc) ₂ ] (5 g) corresponding to urea functionality are mixed in a dichloromethane solvent Stir for 12 hours. After completion of the reaction, the solid silica was collected by filtration, washed sequentially with dichloromethane and methanol, and dried under reduced pressure at room temperature to obtain a palladium catalyst immobilized on silica at a concentration of 7 mmol / g.

Experimental Example 3 Catalytic Reaction of Metal Catalyst Using Modified Spherical Nanosilica

Suzuki reaction for the carbon-carbon bond of phenylboronic acid and para-bromoacetophenyl using a palladium catalyst immobilized on silica prepared in Experimental Example 2 was carried out as follows (see Scheme 2). .

In a mixture of phenylboronic acid (0.017 g, 0.14 mmol) and para-bromoacetophenyl (0.028 g, 0.14 mmol) dissolved in 5 mL of dimethyl formamide, 1.5 equivalents of potassium acetate (0.02 g) and in Experiment 2 Palladium catalyst (0.1 g, 5 mol% Pd) immobilized on the prepared silica was added at room temperature, and then heated to reflux at 120 ° C. for 5 hours. After the reaction was completed, the reaction temperature was cooled to room temperature, and then the solid silica was collected by filtration. After removing solvent from the filtrate, the reaction product was separated and purified by column chromatography (0.026 g, 95%). The catalyst immobilized on silica recovered by filtration was washed sequentially with water and methanol, dried at reduced pressure, and recovered, and the Suzuki reaction was repeated.

reaction One 2 3 4 5 6 7 8 9 10 Yield (%) 95 94 96 93 92 94 93 92 93 91

As shown in Table 1, the Suzuki reaction for the carbon-carbon bond of phenylboronic acid and para-bromoacetophenyl using the immobilized palladium catalyst prepared in Experimental Example 2 was 90. The reaction yield was more than%, and after completion of the reaction, the palladium metal catalyst immobilized on silica was not only recoverable by filtration, but also the catalyst efficacy was maintained even after repeated use.

As described above, according to the present invention, by preparing a double functional ionic liquid having a triethoxysilyl group and a urea group, the silica surface can be easily modified since it has a structure of an imidazole salt. The surface-modified silica can be used for various purposes such as immobilization of a metal catalyst, and also by developing a supported ionic liquid phase catalyst system in which an ionic liquid adsorbed on silica does not melt. It is economical because it enables the recovery and reuse of.

Claims (10)

An ionic liquid having a double functional group of an imidazole salt structure simultaneously containing a trialkoxysilyl group and a urea group represented by the following formula (1). <Formula 1>

(Wherein R ₁ is a C ₁ to C ₄ alkyl group, R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ , R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups, X is any one selected from the group consisting of BF ₄ , PF ₆ , SbF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ , n and m are each independently an integer from 1 to 6.) According to claim 1, wherein in Formula 1 R ₁ is an ethyl group, R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group, R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group, X is any one selected from the group consisting of BF ₄ , PF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ , n and m independently of each other ionic liquid having a double functional group, characterized in that an integer of 1 to 3. According to claim 1 or claim 2, wherein the imidazole salt of Formula 1 is 1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate; 1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate; or 1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide. 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate; 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate; 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide; 1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium hexafluorophosphate; 1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium tetrafluoroborate; or 1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium bistrifluoromethanesulfonylamide Sex liquid. The intermediate compound (II) of claim 1 represented by the following general formula (2): <Formula 2>

(Wherein R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ , R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups, m is independently an integer from 1 to 6) The method according to claim 4, wherein in Formula 2 R ₁ is an ethyl group, R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group, R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group, intermediate compound (II), wherein m is independently an integer from 1 to 3; The compound (II) of claim 4, wherein 1- [3- (N-aminoethylcarbonyl)] aminopropylimidazole; 1- [3- (N-aminopropylcarbonyl)] aminopropylimidazole; or 1- [3- (N-aminobutylcarbonyl)] aminopropylimidazole. An intermediate compound characterized by the above-mentioned. The intermediate compound (III) of claim 1 represented by the following general formula (3): <Formula 3>

(Wherein R ₁ is a C ₁ to C ₄ alkyl group, R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ , R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups, Y is any one selected from the group consisting of Cl, Br and I, n and m are each independently an integer from 1 to 6.) The method according to claim 7, wherein in Formula 3 R ₁ is an ethyl group, R ² , R ³ and R ⁴ are each independently one selected from the group consisting of H, propyl group, butyl group and hexyl group, R ⁵ is any one selected from the group consisting of H, ethyl group, propyl group, butyl group, hexyl group and aryl group, Y is any one selected from the group consisting of Cl, Br and I, Intermediate compound (III), wherein n and m are each independently an integer of 1 to 3. According to claim 7 or 8, wherein the compound of formula (III) 1- [3- (N-aminoethylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride; 1- [3- (N-aminopropylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride; or 1- [3- (N-aminobutylcarbonyl)] aminopropyl-3- [3- (triethoxysilyl)] propylimidazolium chloride. As shown in Scheme 1, R ² , R ^{3 in} positions ² , ⁴ , and ⁵ And R ⁴ Preparing a compound (II) by reacting the substituted amino alkyl imidazole with isocyanate (R ⁵ -N = C═O) (step 1); Preparing a compound (III) by introducing a trialkoxysilyl group into the compound (II) prepared in step 1 (step 2); And Claim 1 to claim 1 characterized by comprising the step (step 3) to prepare a imidazole salt containing a trialkoxysilyl group and urea group at the same time by replacing the Y of the compound (III) prepared in step 2 to X Process for preparing an ionic liquid having a double functional group of formula (1) <Scheme 1>

(Wherein R ₁ is an alkyl group of C ₁ to C ₄ , R ² , R ³ and R ⁴ are, independently from each other, H or an alkyl group of C ₁ to C ₆ , R ⁵ is any one selected from the group consisting of H, C ₁ to C ₁₆ alkyl groups and aryl groups, X is any one selected from the group consisting of BF ₄ , PF ₆ , SbF ₆ , NO ₃ , ClO ₄ , OSO ₂ CF ₃ and N (SO ₂ CF ₃ ) ₂ , Y is any one selected from the group consisting of Cl, Br and I, n and m are each independently an integer from 1 to 6.)