KR100739452B1 - A Process for Preparing ?-Alkylpyrrole Compounds - Google Patents

Abstract

The present invention relates to a method for preparing an α-alkylpyrrole compound. Specifically, in preparing an α-alkylpyrrole compound by reacting a pyrrole compound with an alkyl halide or an alkyl sulfonate under basic conditions, The present invention relates to a method for producing an α-alkylpyrrole compound, which is used as a solvent or a mixed solvent with an organic solvent. The production method of the α-alkylpyrrole compound of the present invention has a high yield and mass production because the reaction conditions are gentle and the reaction time is shortened, and the carbon-carbon bond formation reaction, that is, the selectivity to C-alkylation of the pyrrole compound is excellent. Useful for

Description

A Process for Preparing α-Alkylpyrrole Compounds

The present invention is to prepare an α-alkylpyrrole compound by reacting a pyrrole compound with an alkyl halide or alkyl sulfonate under basic conditions, wherein the imidazolyne salt is used as a single solvent or a mixed solvent with an organic solvent. A method for producing an α-alkylpyrrole compound.

Formation of carbon-carbon bonds that form the backbone of organic compounds is recognized as a very important field in organic synthesis. One of the most basic methods of forming such carbon-carbon bonds is to use C-alkylation reactions of heteroaromatic compounds rich in π electrons [Joule, JA; Mills, K .; Smith, GF Heterocyclic Chemistry , 3rd ed., Chapman & Hall: London, 1995 , p 231; Schofield, K. Heteroaromatic Nitrogen Compounds: Pyrroles and Pyridines , Plenum Press: New York, 1967 p 3 .; Fisher, H .; Orth, H., "Die Chemie des Pyrroles," Vol. 1 and 2, Akademische Verlag, Liepzig, 1934 reproduced by Johnson Reprint Corporation, New York, 1968 (b) Jones, RA; Bean, GP ' The Chemistry of Pyrroles ,' Academic Press, New York, 1977 , Vol. 34, p 525.].

Of the π-rich heteroaromatic compounds, pyrrole is a precursor that can be used as a medicine and is a very useful substance as a basic unit of the polypyrrole macro compounds used in various fields. Important [Livingstone, R. In Rodd's Chemistry of Carbon Compounds; Ansell, MF, Ed .; Elsevier: Oxford, 1984 Vol. 4.].

A method of introducing an alkyl group to the α position of the pyrrole by performing a Wolfs-Kishner reduction reaction after a Vylsmeier-Haack formylation reaction using a conventional C-alkylation method of pyrrole There is this. However, this method is not efficient in terms of yield and economy since it consists of two stage reactions [Skell, PS; Bean, GP 1962 , 84 , 4655 .; Jacobson, MA; Williard, PG J. Org. Chem . 2002 , 67 , 3 .; White, J .; McGillivray, G. J. Org. Chem . 1977 , 42 , 4248 .; Cooper, GH J. Org. Chem . 1971 , 36 , 2897; Kakushima, M .; Hamel, P .; Frenette, R .; Rokach, J. J. Org. Chem . 1983 , 48 , 3214; Anderson, HJ; Loader, CE In Pyrroles; Jones, RA; Ed .; Wiley-Interscience: New York, 1990 , Part 1, p 444.]. Therefore, it is necessary to increase the yield and economy by reducing the reaction process in one step.

In general, the C-alkylation reaction of pyrrole in one step is carried out by reacting pyrrole with an alkyl halide or alkyl sulfonate to form a carbon-carbon bond at the C2 or C5 position of the pyrrole as shown in Scheme 1 below to form α-alkylpyrrole. To prepare a compound.

In the alkyl halide or alkyl sulfonate, the halide is selected from the group consisting of F, Cl, Br and I, sulfonate is -SO ₃ R ¹⁶ , R ¹⁶ is an alkyl group or an aryl group, specifically, an alkyl group A C ₁ to C ₁₂ alkyl group and a halo C ₁ to C ₁₂ alkyl group are preferable, and the aryl group is preferably a phenyl group, a C ₁ to C ₄ alkyl phenyl group, a halophenyl group, a C ₁ to C ₄ alkoxy phenyl group, or a nitrophenyl group. Specific examples of alkyl sulfonates include methanesulfonate, ethanesulfonate, isopropanesulfonate, chloromethanesulfonate, trifluoromethanesulfonate, chloroethanesulfonate, methylphenylsulfonate, ethylphenylsulfonate, chlorophenylsulfonate , Bromophenylsulfonate, methoxyphenylsulfonate or nitrophenylsulfonate.

The pyrrole compound is any compound having a pyrrole ring, R ¹² R ¹³ R ¹⁴ and R ¹⁵ are each independently hydrogen, C ₁ ~ C ₁₈ alkyl group, aryl group, nitro group, hydroxyl group, cyano group, halogen group Are various substituents. Among the pyrrole compounds, pyrrole has been widely used as a source of the pyrrole compound because it is inexpensive, economical and stable.

In the method for preparing the α-alkylpyrrole compound, an α-alkyl is introduced by introducing an alkyl group to the α-position of pyrrole, a heteroaromatic compound rich in pi electrons, through a Friedel-Crafts alkylation reaction under acidic conditions. A method for obtaining pyrrole compounds has been reported. However, the Bronsted acid or Lewis acid used in this reaction is not practical because it has the disadvantage of causing polyalkylation, ring opening or polymer reaction of pyrrole [Joule, JA; Mills, K .; Smith, GF Heterocyclic Chemistry , 3rd ed., Chapman & Hall: London, 1995 ; p 231; Schofield, K. Heteroaromatic Nitrogen Compounds: Pyrroles and Pyridines , Plenum Press: New York, 1967 p 3.].

The method of carrying out the nucleophilic substitution reaction of pyrrole in the presence of a base at a high temperature as shown in Scheme 2 is accompanied by N-alkylation of pyrrole because there is no selectivity to C-alkylation [Patterson, JM; Soedigdo, S. J. Org. Chem . 1968 , 33 , 2057.]. In order to avoid such N-alkylation of pyrrole, pyrrolyl magnesium halide may be prepared and then optionally used to obtain an α-alkylpyrrole compound. However, this method has the disadvantage that the reaction conditions are severe, dangerous and not economical [Baltazzi, E .; Krimen, E. Chem. Rev. 1963 , 63 , 511; Loader, CE; Anderson, HJ Can. J. Chem . 1971 , 49 , 1064; Nicolaou, KC; Claremon, DA; Papahatjis, DP Tetrahedron Lett . 1981 , 22 , 4647.].

Accordingly, in preparing the α-alkylpyrrole compound by reacting a pyrrole compound with an alkyl halide or an alkyl sulfonate under basic conditions, the reactivity of the pyrrole compound is shortened to increase reaction time and increase selectivity to produce byproduct N-alkylpyrrole. There is a need for the development of effective and economical manufacturing methods that can reduce the production of compounds.

On the other hand, salts composed of organic cation groups (imidazolizol, pyridinini, ammonia) and anions, which are stable to air and moisture, are not volatile and flammable, and generally exist as liquids below 100 ° C. It is called (Ionic Liquid), and it has excellent dissolving ability in various organic and inorganic substances, does not decompose in water, and has stable characteristics under various chemical reaction conditions.

Among the ionic liquids, especially imidazolysin salts have a unique solvent effect due to the strong ionicity not observed in general organic solvents, which greatly contributes to the improvement of reaction rate and selectivity in various chemical reactions, and has no volatility. Therefore, it can be recovered without loss after the reaction, attracting attention as a next-generation clean solvent [Welton, T. Chem. Rev. 1999 , 99 , 2071 .; Wasserscheid, P .; Keim, W. Angew. Chem. Int. Ed . 2000 , 39 , 3772 .; Song, CE; Shim, WH; Roh, EJ; Lee, S.-g .; Choi, JH Chem. Commun . 2001 , 1122 .; Song, CE; Shim, WH; Roh, EJ; Choi, JH Chem. Commun . 2000 , 1695.].

In order to solve the above problems with respect to C-alkylation of the pyrrole compound, the present inventors have reacted the pyrrole compound with an alkyl halide or alkyl sulfonate under basic conditions to prepare an α-alkylpyrrole compound. As a result of using as a single solvent or a mixed solvent with an organic solvent, the present invention was completed by obtaining an α-alkylpyrrole compound having remarkably improved selectivity and yield for C-alkylation under mild reaction conditions.

The present invention is to prepare an α-alkylpyrrole compound by reacting a pyrrole compound with an alkyl halide or an alkyl sulfonate under basic conditions, wherein the α-alkylpyrrole compound has mild reaction conditions and significantly improved selectivity and yield for C-alkylation. To provide a method for manufacturing

The present invention is to prepare an α-alkylpyrrole compound in which a pyrrole compound is reacted with an alkyl halide or alkyl sulfonate under basic conditions to form a carbon-carbon bond at the C2 or C5 position of the pyrrole compound. Provided is a method for producing an α-alkylpyrrole compound, which is used as a single solvent or a mixed solvent with an organic solvent.

(Wherein

R ¹ is a C ₁ to C ₁₈ alkyl group;

R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen or a C ₁ to C ₁₈ alkyl group;

A ^n- is an anion capable of forming a salt;

n is an integer of 1-3.)

Hereinafter, the present invention will be described in detail.

The imidazolysin salt represented by Formula 1 may improve melting point, affinity with water, and chemical stability depending on the composition of the macromolecular cationic group. The higher the carbon number of the alkyl group of the imidazolysin ion, which is a cation, and the more alkyl substituents, the higher the melting point of the salt, and thus the reaction temperature of the reaction using the same as a solvent should be increased. In consideration of this tendency, R ¹ is a C ₁ to C ₁₈ alkyl group, preferably a C ₁ to C ₈ alkyl group, and more preferably a C ₁ to C ₄ alkyl group. C ₁ -C ₄ alkyl groups include methyl, ethyl, propyl, butyl, isopropyl, t -butyl and the like.

R ² is hydrogen or a C ₁ to C ₁₈ alkyl group, preferably hydrogen or a C ₁ to C ₆ alkyl group, more preferably hydrogen or methyl.

R ³ is hydrogen or a C ₁ to C ₁₈ alkyl group, preferably hydrogen or a C ₁ to C ₈ alkyl group, and more preferably R ³ is a C ₂ to C ₈ alkyl group. C ₂ to C ₈ alkyl groups include ethyl, propyl, butyl, pentyl, hectyl, heptyl, octyl and the like.

R ⁴ and R ⁵ are each independently hydrogen or a C ₁ to C ₁₈ alkyl group, preferably hydrogen or a C ₁ to C ₆ alkyl group, and most preferably hydrogen.

Preferred examples of the imidazolysin ion which is a cation of the imidazolysin salt represented by the formula (1) are as follows:

1-ethyl-3-methyl-imidazolium (emyl),

1-methyl-3-propyl-imidazolium (1-methyl-3-propyl-imidazolium; pmim),

1-butyl-3-methyl-imidazolium 윰 (1-buthyl-3-methyl-imidazolium; bmim),

1-methyl-3-pentyl-imidazolium (mpim),

1-hecyl-3-methyl-imidazolium (hmim),

1-heptyl-3-methyl-imidazolium (hpmim),

2,3-dimethyl-1-propyl-imidazolium (2,3-dimethyl-1-propyl-imidazolium),

1-propyl-2,3,4,5-tetramethyl-imidazolium (1-propyl-2,3,4,5-tetramethyl-imidazolium).

The most preferred of these is 1-butyl-3-methyl-imidazolysin.

In addition, the imidazolysin salt may improve melting point, affinity with water, and chemical stability depending on the composition of the anion [A ⁿ⁻ ]. The anion affects the physical, chemical and chemical stability of the imidazolysin salt and should not cause side reactions or degrade. Any such anion can be used as long as it is an anion capable of forming a salt.

The anion is _{^{preferably, MF k -, R 6 O}} -, R 7 R 8 N - or R ⁹ R ¹⁰ R ¹¹ C ^-, and wherein M is an element of 3 to group 15 on the periodic table, k is 2 to Is an integer of 6. R ⁶ is C ₁ to C ₁₂ alkylsulfone, halo C ₁ to C ₁₂ alkylsulfone, C ₁ to C ₄ alkyl arylsulfone, halo arylsulfone, halosulfone, phosphoryl or perfluoro C ₁ to C ₁₂ alkylcarbons R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are each independently C ₁ -C ₁₂ alkylsulfone, halo C ₁ -C ₁₂ alkylsulfone, C ₁ -C ₄ alkyl arylsulfone or halo aryl It's a sulfone.

Preferred examples of the anion [A ^n-] is borate (BF ₄ ^-) tetrafluoroborate, hexafluorophosphate (PF ₆ ^-), antimonate hexafluorophosphate (SbF ₆ ^-), trifluoromethanesulfonate ( _{^{OSO 2 CF 3 -; OTf -}} ) and bis (trifluoromethyl sulfonyl) imide _{(N (SO 2 CF 3)} 2 -; NTf 2 - , and a), most preferably antimonate hexafluoropropane.

The imidazolysin salt used in the present invention is used as a mixed solvent of a single solvent or an organic solvent to increase the solubility of the pyrrole compound and the alkyl halide or alkyl sulfonate, and to increase the alkylation rate of the C2 or C5 position of the pyrrole compound. Increase and inhibits side reactions, N-alkylation. The organic solvents include chemically stable solvents that can be used for the reaction, specifically, acetonitrile, tetrahydrofuran, 1,4-dioxane and t -butanol are preferred, and acetonitrile is most preferred.

The amount of imidazolysin salt used in the present invention is preferably 0.5 to 18.0 equivalents, more preferably 10.0 to 12.0 equivalents, to the alkyl halide or alkyl sulfonate when used as a single solvent or as a mixed solvent mixed with an organic solvent. Do.

The pyrrole compound used in the preparation of the α-alkylpyrrole compound of the present invention is an arbitrary compound having a pyrrole ring, as represented by the following Formula 2, and R ¹² R ¹³ R ¹⁴ and R ¹⁵ are each independently hydrogen, C ₁ to C ₁₈ alkyl group, aryl group, nitro group, hydroxyl group, cyano group, halogen group or alkoxy group.

Under the present circumstances, it is preferable to use 2.0-20.0 equivalent with respect to an alkyl halide or alkyl sulfonate, More preferably, 8.0-12.0 equivalent is used.

The base used in preparing the α-alkylpyrrole compound of the present invention is used to neutralize the acid generated during the reaction. The base includes carbonate salts, bicarbonate salts or hydroxide salts of alkaline earth metals including magnesium, calcium, strontium and barium, or alkali metals including sodium, potassium, rubidin, and cesium, among which potassium Carbonate salts are preferred. The metal base is used in the amount of 0.1 to 2.0 equivalents based on the alkyl halide or alkyl sulfonate.

In preparing the α-alkylpyrrole compound of the present invention, the reaction conditions are 10 hours to 7 days at 50 to 200 ° C, preferably 24 to 72 hours at 80 to 130 ° C, and most preferably 40 to 100 to 120 ° C. It is-48 hours.

When the α-alkylpyrrole compound of the present invention is used, the imidazolysin salt is used as a single solvent or a mixed solvent with a mixed solvent to suppress side reactions to selectively obtain the α-alkylpyrrole compound as a main product in a high yield of 80% or more. Can be. On the other hand, if the reaction proceeds without the addition of imidazoline, the α-alkylpyrrole compound is hardly produced. Therefore, the method of preparing the α-alkylpyrrole compound of the present invention increases the reactivity and the reaction rate by using the imidazolysone salt as a single solvent or a mixed solvent with an organic solvent, thereby making the reaction conditions milder and shortening the reaction time. The yield is markedly improved by increasing the carbon bond formation reaction, i.e. the selectivity to C-alkylation of the pyrrole compound.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, the following examples are merely to illustrate the content of the present invention, the present invention is not limited by the following examples.

I. Reactivity with Changing Composition of Mixed Solvents.

<Example 1>

1-Bromo-3-phenylpropane (199 mg, 1.0 mmol), potassium carbonate (110 mg, 0.8 mmol) and pyrrole (0.7 mL, 10 mmol) were dissolved in 1-butyl-3-methyl-imidazolysin hexafluor Roantimonate (hereinafter, referred to as '[bmim] [SbF ₆ ]') was added to a 3.0 ml single solvent to prepare a reaction solution. The reaction solution was stirred at a reaction temperature of 115 ° C. for 44 hours, and then extracted 5 times with 7 ml of ethyl ether. The extract was dried over anhydrous sodium sulfate, filtered and concentrated using a distillation under reduced pressure. The concentrate was subjected to column chromatography (ethyl acetate: n-hexane = 1:20) to obtain 2- (3-phenylpropyl) -1 H -pyrrole (150 mg, 81%).

<Examples 2 to 8>

The composition and the reaction time of the mixed solvent containing [bmim] [SbF ₆ ] were changed in the same manner as in Example 1, except that the composition was changed as shown in Table 1 below.

Scheme 3 below shows the by-product 2,5-bis- (3-phenylpropyl) -1 together with 2- (3-phenylpropyl) -1 H -pyrrole ( A ) as the main product in the reactions of Examples 1-9. It is shown that H -pyrrole ( B ) or 3-phenylpropyl 1 H -pyrrole-1-carbonylate ( C ) can be produced.

Comparative Example 1

1-bromo-3-phenylpropane (199 mg, 1.0 mmol), potassium carbonate (110 mg, 0.8 mmol) and pyrrole (0.7 mL, 10 mmol) were added to acetonitrile (CH without addition of [bmim] [SbF ₆ ]). ₃ CN) was added to 3 ml of a single solvent to prepare a reaction solution. The reaction solution was stirred at a reaction temperature of 115 ° C. for 7 days.

The results of Examples 1 to 9 and Comparative Examples are shown in Table 1 below.

Solvent Composition Reaction time yield(%) [bmim] [SbF ₆ ] mL (equivalent) CH ₃ CN ml Starting material ( SM ) Substance A B C Example 1 3.0 - 44 - 81 10 - Example 2 3.0 - 48 - 80 8 - Example 3 2.7 0.3 44 - 84 7 - Example 4 2.4 0.6 44 - 86 5 - Example 5 2.0 1.0 48 - 83 6 - Example 6 1.0 2.0 72 29 53 10 a very small amount Example 7 0.5 2.5 72 36 45 11 a very small amount Example 8 0.1 2.9 7 days 55 26 4 5 Comparative Example 1 - 3.0 7 days 85 5 4 a very small amount

As shown in Table 1 above, when the reaction of Scheme 3 was carried out using the imidazolysin salt [bmim] [SbF ₆ ] of the present invention as a single solvent or a mixed solvent mixed with acetonitrile, α-alkyl 2- (3-phenylpropyl) -1 H -pyrrole ( A ) as a pyrrole compound can be obtained in a yield of 80% or more.

On the other hand, when [bmim] [SbF ₆ ] is mixed with other organic solvents acetonitrile and used as a mixed solvent, the reactivity decreases significantly and the reaction time increases as the number of equivalents of [bmim] [SbF ₆ ] decreases. It can be seen that the yield of the main product 2- (3-phenylpropyl) -1 H -pyrrole ( A ) is significantly reduced and the production rate of the by-product is increased. (Example 6-Example 8).

In addition, in Comparative Example 1 without using [bmim] [SbF ₆ ], almost no reaction proceeded for 7 days, which is the maximum reaction time. Therefore, it can be seen that the role of [bmim] [SbF ₆ ] is essential in the preparation of the α-alkylpyrrole compound according to the present invention.

II. Reactivity with Change of Anion

Example 9

1-Bromo-3-phenylpropane (199 mg, 1.0 mmol), potassium carbonate (110 mg, 0.8 mmol), and pyrrole (0.7 mL, 10 mmol) were dissolved in 1-butyl-3-methyl-imidazolysin hexa. A reaction solution was prepared by adding 2.4 ml of fluorophosphate (hereinafter referred to as '[bmim] [PF ₆ ]') and a mixed solvent of 0.6 ml of acetonitrile. The reaction solution was stirred at a reaction temperature of 115 ° C. for 44 hours, and then extracted 5 times with 7 ml of ethyl ether. The extract was dried over anhydrous sodium sulfate, filtered and concentrated using a distillation under reduced pressure. The concentrate was subjected to column chromatography (ethyl acetate: n-hexane = 1: 20) to give 2- (3-phenylpropyl) -1 H -pyrrole ( A ) (126 mg, 68%) and 3-phenylpropyl 1 H -pyrrole-1-carbonylate ( C ) was obtained (48 mg, 21%).

<Examples 10 to 14>

The same process as in Example 9 was carried out except that the type of imidazolysin salt, the type of organic solvent used together with the reaction time were changed as shown in Table 2 below.

Imidazolysinitis Organic solvent Response time (H) Yield SM A B C Example 9 [bmim] [PF ₆ ] CH ₃ CN 46 - 68 2 21 Example 10 [bmim] [NTf ₂ ] CH ₃ CN 48 - 65 3 24 Example 11 [bmim] [OTf] CH ₃ CN 72 35 51 2 4 Example 12 [bmim] [BF ₄ ] CH ₃ CN 45 - 25 2 2 Example 13 [bmim] [SbF ₆ ] toluene 46 - 57 10 2 Example 14 [bmim] [SbF ₆ ] 1,4-dioxane 46 - 60 8 2

As shown in Table 2 above, when the anion constituting the salt of imidazolizin was BF ₄ ⁻ , the main product 2- (3-phenylpropyl) -1 H -pyrrole ( A ) was obtained in low yield. When NTf ₂ ^- _and PF ₆ ^- were used as the anion constituting the salts of imidazolidone, the main product ( A ) was obtained in a yield of 60% or more, but 3-phenylpropyl 1 H -pyrrole-1-carbo as a by-product. Nilate ( C ) was more than 20% produced. It was also found that the reactivity was quite low when the anion was OTf ⁻ . Therefore, it can be seen that SbF ₆ ⁻ is most preferable as an anion constituting the salt of imidazolizin in the production method of the present invention.

In addition, when imidazolysin was used as a mixed solvent, satisfactory yield of 50 to 60% or more was obtained even when toluene or 1,4-dioxane was used in addition to acetonitrile as the organic solvent.

III. Reactivity with various alkyl halides and alkyl sulfonates

<Example 15>

1-methanesulfonyloxy-3-phenylpropane (214 mg, 1.0 mmol), potassium carbonate (110 mg, 0.8 mmol), and pyrrole (0.7 mL, 10 mmol) in 2.4 mL [bmim] [SbF ₆ ], aceto The reaction solution was prepared in a mixed solvent of 0.6 ml of nitrile. The reaction solution was stirred at a reaction temperature of 115 ° C. for 44 hours, extracted five times with 7 ml of ethyl ether, and the extract was dried over anhydrous sodium sulfate, filtered, and concentrated using a vacuum distillation unit. The concentrate was subjected to column chromatography (ethyl acetate: n-hexane = 1:20) to obtain 2- (3-phenylpropyl) -1 H -pyrrole (152 mg, 82%).

<Examples 16 to 26>

Instead of 1-methanesulfonyloxy-3-phenylpropane (214 mg, 1.0 mmol) used in Example 15, 1.0 mmol of various alkyl halides or alkyl sulfonates was used as shown in Table 3 , and the reaction time was changed. Except that, it was carried out in the same manner as in Example 15.

Alkyl halides or alkyl sulfonates Response time (h) yield(%) Example 15

44 82 Example 16

48 60 Example 17

36 76 Example 18

72 80 Example 19

3 80 Example 20

58 82 Example 21

56 72 Example 22

62 82 Example 23

60 70 Example 24

68 78 Example 25

66 75 Example 26

72 73

Shown in Table 3 above As described above, the method of preparing the α-alkylpyrrole compound of the present invention may vary in reaction time and reactivity depending on the alkyl halide or alkyl sulfonate used, but in the case of Examples 15 to 26, 115 ° C and 3 to 72 hours. The α-alkylpyrrole compound could be prepared in good yield under mild reaction conditions.

 The production method of the α-alkylpyrrole compound of the present invention has a high yield and is useful for mass production because the reaction conditions are gentle and the reaction time is shortened, and the selectivity to the carbon-carbon bond formation reaction, ie, C-alkylation is excellent. .

Claims (15)

The pyrrole compound of formula (2) is reacted with an alkyl halide of formula (3) or an alkyl sulfonate of formula (4) under basic conditions selected from the group consisting of carbonate salts, bicarbonate salts and hydroxy salts of alkaline earth metals or alkali metals. In the method for preparing the α-alkylpyrrole compound by forming a carbon-carbon bond in the C2 or C5 position, the imidazolysin salt of the formula (1 ) is used as a single solvent or mixed solvent with an organic solvent Process for preparing α-alkylpyrrole compound. <Formula 1>

(Wherein R ¹ is a C ₁ to C ₈ alkyl group; R ² , R ³ , R ⁴ and R ⁵ are each independently hydrogen or an alkyl group of C ₁ to C ₄ ; A ⁿ of A is BF ₄ , PF ₆ , SbF ₆ , NTf ₂ Or TfO; n is 1) <Formula 2>

(Wherein R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are each independently hydrogen, a C ₁ to C ₄ alkyl group, a nitro group, a hydroxyl group, a cyano group or a halogen group.) <Formula 3> R-X (In Chemical Formula 3, R is a C ₁ to C ₄ alkyl group substituted with a phenyl, naphthyl group or naphthyl oxy group; Or a C ₁ to C ₁₅ alkyl group; X is F, Cl, Br or I.) <Formula 4> -SO ₃ R ¹⁶ (In Formula 4, R ¹⁶ is a C ₁ to C ₄ alkyl group substituted with a phenyl, naphthyl group or naphthyloxy group; Or a C ₁ to C ₄ alkyl group.) delete The compound according to claim 1, wherein in the imidazolysin salt of Formula 1, R ¹ is a C ₁ to C ₄ alkyl group; R ² is Hydrogen or methyl; R ³ is a C ₂ to C ₈ alkyl group; R ⁴ and R ⁵ are each a method for producing an α-alkylpyrrole compound. The method of claim 3, wherein the cation of the imidazolizin salt of Formula 1 is 1-ethyl-3-methyl-imidazolysin, 1-methyl-3-propyl-imidazolysin, 1-butyl-3-methyl -Imidazolizin, 1-methyl-3-pentyl-imidazoli 윰, 1-hexyl-3-methyl-imidazoli 윰, 1-heptyl-3-methyl-imidazoli 윰, and 2,3-dimethyl 1-propyl-imidazolybene, the method for producing an α-alkylpyrrole compound, characterized in that selected from the group consisting of. delete delete The method according to claim 1, wherein the cation of the imidazolysin salt of Formula 1 is 1-butyl-3-methyl-imidazolium (1-buthyl-3-methyl-imidazolium), and the anion is BF ₄ ⁻ , PF ₆ ^-, SbF ₆ ^-, NTf ₂ ^- and TfO ^- a method for producing an α-alkylpyrrole compound, characterized in that one selected from the group consisting of. The method for producing α-alkylpyrrole compound according to claim 1, wherein the imidazolysin salt of the formula (1) is used in an amount of 0.5 to 18.0 equivalents relative to the alkyl halide or alkyl sulfonate. delete The method for producing α-alkylpyrrole compound according to claim 1, wherein the pyrrole compound is used in an amount of 2.0 to 20 equivalents based on the alkyl halide or alkyl sulfonate. delete The method for producing α-alkylpyrrole compound according to claim 1, wherein the base is potassium carbonate. The method for producing an α-alkylpyrrole compound according to claim 1, wherein the base is used in an amount of 0.1 to 2.0 equivalents based on alkyl halide or alkyl sulfonate. The alpha solvent according to claim 1, wherein the organic solvent used with the imidazolysin salt is at least one solvent selected from the group consisting of acetonitrile, tetrahydrofuran 1,4-dioxane and t -butanol. Process for the preparation of alkylpyrrole compounds. The process for producing α-alkylpyrrole compound according to claim 14, wherein the organic solvent is acetonitrile.