WO2008111794A1

WO2008111794A1 - 4-methylimidazol-5-ylcarbonylguanidine derivatives, pharmaceutically acceptable salts thereof, preparation method, and pharmaceutical compositions for the prevention and treatment of the ischemic heart diseases containing the same as an active ingredient

Info

Publication number: WO2008111794A1
Application number: PCT/KR2008/001395
Authority: WO
Inventors: Kyu Yang Yi; Sunkyung Lee; Sung-Jun Yoon; Byung Ho Lee; Kwang Seok Oh; Yi-Sook Jung
Original assignee: Korea Reserach Institute Of Chemical Technology
Priority date: 2007-03-12
Filing date: 2008-03-12
Publication date: 2008-09-18
Also published as: KR100820173B1

Abstract

Disclosed are novel 4-methylimidazol-5- ylcarbonylguanidine derivatives, pharmaceutically acceptable salts thereof, preparation methods thereof, and pharmaceutical composition for the prevention and treatment of ischemic heart diseases, comprising the same as an active ingredient. Having potent inhibitory activity against NHE-I and excellent protective effects on the heart against ischemia/reperfusion, the novel 4-methylimidazol-5- ylcarbonylguanidine derivatives can be used for the prophylaxis and treatment of ischemic cardiac diseases such as myocardiac infarction, arrhythmia, and angina pectoris and can serve as a cardioprotective agent applicable for coronary reperfusion therapy with coronary artery bypass, percutaneous transluminal coronary angioplasty, and/or thrombolytics for myocardiac infarction.

Description

[DESCRIPTION]

[invention Title]

4-l^THYLIlyπ:DAZOL-5-YLCLARBONYLGϋANIDINE DERIVATIVES,

PHARMACEUTICALLY ACCEPTABLE SALTS THEREOF, PREPARATION METHOD, AND PHARMACEUTICAL COMPOSITIONS FOR THE PREVENTION

AND TREATMENT OF THE ISCHEMIC HEART DISEASES CONTAINING THE

SAME AS AN ACTIVE INGREDIENT

[Technical Field]

The present invention relates to 4-methylimidazol-5- ylcarbonylguanidine derivatives, pharmaceutically acceptable salts thereof, preparation methods thereof, and compositions for the prevention and treatment of ischemic heart diseases comprising the same as an active ingredient.

[Background Art] Serving as ion channels for Na⁺-H⁺ counter transport across the plasma membrane, the sodium-hydrogen exchangers (hereinafter referred to as "NHE" ) , expressed in various cell species, maintain intracellular pH homeostasis by the electroneutral exchange of intracellular H⁺ for extracellular Na⁺. Seven isoforms of NHEs have been identified, thus far. Of them, NHE-I, the major isoform in myocardial cells, has been known as a plasma protein which is not only involved in the regulation of intracellular pH, sodium ion concentration and cell size, but also plays a pivotal role in myocardial ischemic-reperfusional injury

[Avkiran, M. et al. , (2002) J. Am. Coll. Cardiol. 39: 747-

753] . NHE-I almost never works in the normal physiological pH condition (7.2) . Intracellular energy production depends on glycolysis in an ischemic condition because of the lack of oxygen, resulting in the accumulation of hydrogen ions in the cell (pH 6.4) . In turn, NHE-I, which has a proton sensor, is activated to extrude H⁺ from cells with the counter transport of Na⁺ into the cell, resulting in intracellular Na⁺ overload. Upon ischemia, Na⁺/K⁺ ATPase is inhibited as a result of a decrease in energy production, so that the accumulated Na ions cannot be excluded from the cells by the sodium pump. When it is subjected to intracellular Na+ overload, NCX (Na⁺/Ca²⁺ exchanger) , which functions to transport calcium ions from cells and sodium ions into cells under a normal condition, is altered to operate in a reversal mode, leading to pathologic intracellular Ca²⁺ overload. That is, an increase of intracellular calcium ions activates enzymes, such as proteases, phospholipase, endonucleases , etc., to cause protein degradation, ROS (reactive oxygen species) increase via the defect of lipid metabolism, DNA damage, and finally, cell injury. Therefore, the blockage of intracellular Na ion overload by inhibiting NHE-I suppresses the reverse operation of NCX to limit intracellular Ca ion overload, which affords a presumable mechanism for cardioprotection against ischemia/reperfusion. It is reported that the inhibition of NHE-I dose not induce intracellular acidosis as the increased intracellular hydrogen ion concentration can be regulated by other ion channels .

Although basic and clinical studies thereof have been extensively conducted for the last 50 years, ischemic heart diseases, such as myocardial infarction, arrhythmia, heat failure, etc., caused by myocardial cell injury and cardiac insufficiency upon ischemia/reperfusion, still show high prevalence rate and mortality (Kloner, R.A. et al., (2004) J. Am. Coll. Cardiol., 44: 276-286). Because various physiological mechanisms, such as metabolic changes, immune responses, perturbation of ionic homeostasis, oxygen free radicals, etc. are implicated in ischemia/reperfusion injury, studies on the physiological mechanisms are conducted in association with immune regulators, apoptosis related substances and ion channel regulators . In addition to these studies, new therapeutic approaches and surgical procedures have been actively investigated. Nonetheless, any novel technique to protect myocardial cells from ischemia/reperfusion has not yet been adopted clinically. Although coronary reperfusion therapy with chemicals such as thrombolytic agents, or surgery such as coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty immediately after ischemic heart diseases such as acute myocardial infarction, arrhythmia, heart failure, etc . , increases the chances of survival of patients suffering therefrom, the effect thereof remains controversial because of aftereffects including a significant recurrence frequency of myocardiac infarction or arrhythmia, or a decrease in heart function or neurocognitive ability [Robert, M. (2003) Ann. Thorac. Surg. 75: S700-708] . Thus, there is a need for a safe and effective cardioprotecting agent that can delay the progress of ischemic injury to cardiomyocytes and attenuate reperfusion-caused injuries.

Animal experiments indicated that NHE-I inhibitors reduce intracellular sodium ion concentration and suppress calcium overload, bringing about cardioprotection against ischemic/reperfusional injuries, such as heart failure or cardiomyocyte necrosis (Avkiran, M. et al., (2002) J. Am. Coll. Cardiol., 39, 747). Thus, NHE-I inhibitors are now being under study on the use thereof as protectors against ischemic/reperfusional injuries. The pyrazine derivative amiloride, used as a diuretic agent, was first found to function as an NHE inhibitor [Benos, DJ. (1982) A. J. Physiol. 242: C131] . In a rat heart model, amiloride was observed to promote heart function recovery after ischemia/reperfusion, in addition to inhibiting NHE-I. However, amiloride has a problem as a cardioprotective agent due to poor selectivity for NHE-I, as it was found to inhibit NHE-2 and sodium channels as well as NHE-I.

Hence, extensive research has been done in order to develop drugs specific for NHE-I, and Hoechst Marion Roussel (now Aventis) succeeded in developing cariporide (HOE-694) , a benzoyl guanidine derivative highly specific for NHE-I

[Scholz, W. et. al., (1993) Br. J. Pharmacol. 109: 562]. In an animal model, cariporide was proven to show good cardioprotective effects. Almost all of the NHE-I inhibitors known so far are acyl guanidines, as exemplified by the selective NHE-I inhibitors zoniporide, sabiporide, EMD-7580, etc.

The NHE-I inhibitor has been proven to improve myocardial contractility and metabolic status, and to reduce arrhythmia, apoptosis, necrosis, and intracellular overload of Na⁺ and Ca, indicating that it has cardioprotective activity against ischemic/reperfusional injury [Karmazyn, M (2002) Science & Medcine : 18-26] . Thus, NHE-I selective inhibitor can be a promising candidate for a cardioprotective agent applicable for coronary reperfusion therapy or cardiac surgery with coronary artery bypass graft, percutaneous transluminal coronary angioplasty and/or thrombolytics for acute myocardiac infarction and therefore will live up to the hope of treatment and prevention of a broad spectrum of ischemic heart diseases including heart failure, arrhythmia, etc. Leading to the present invention, intensive and thorough research on selective MHE-I inhibitors, conducted by the present inventors, resulted in the finding that 4- methylimidazol-5-ylcarbonylguanidine derivatives are selectively inhibitory of NHE-I activity and effective in functional recovery of ischeraia/reperfusion-induced myocardial injury in addition to having a significant reduction in cerebral infarction size and myocardiac infarction size, thereby greatly contributing to the treatment and prophylaxis of ischemic heart diseases.

[Disclosure] [Technical Problem]

It is an object of the present invention to provide novel 4-methylimidazol-5-ylcarbonylguanidine derivatives or pharmaceutically acceptable salts thereof.

It is another object of the present invention to provide a method for the preparation of novel 4- methylimidazol-5-ylcarbonylguanidine derivatives or pharmaceutically acceptable salts thereof . It is a further object of the present invention to provide a composition for the prevention and treatment of ischemic heart disease, containing a novel 4-methylimidazol- 5-ylcarbonylguanidine derivative or a pharmaceutically acceptable salt thereof as an active ingredient . [Technical Solution]

In order to accomplish the above objects, the present invention provides novel 4-methylimidazol-5- ylcarbonylguanidine derivatives, pharmaceutically acceptable salts thereof, a method for the preparation of novel 4- methylimidazol-5-ylcarbonylguanidine derivatives, and a pharmaceutical composition for the prevention and treatment of ischemic heart disease, containing a novel 4- methylimidazol-5-ylcarbonylguanidine derivative or a pharmaceutically acceptable salt thereof as an active ingredient .

[Advantageous Effects]

The 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention are found to have potent inhibitory activity against the sodium/hydrogen exchanger NHE-I, promote the functional recovery of ischemia/reperfusion- induced heart injury in isolated ischemic heart models, and significantly reduce the myocardiac infarct size in in vivo ischemic animal models, thereby showing excellent cardioprotective effects. Therefore, the 4-methylimidazol- 5-ylcarbonylguanidine derivatives of the present invention can be effectively used for the prophylaxis and treatment of ischemic heart diseases such as myocardiac infarction, arrhythmia, angina pectoris and the like, and can be used as cardioprotective agents for reperfusion therapy using chemicals such as thrombolytic agents, or surgery such as coronary artery bypass and percutaneous transluminal coronary angioplasty.

[Best Mode] The present invention pertains to novel 4- methylimidazol-5-ylcarbonylguanidine derivatives , represented by the following chemical formula 1, and pharmaceutically acceptable salts thereof :

[Chemical Formula l]

wherein,

R¹ and R² are each independently hydrogen, a halogen atom, trihalomethyl, mesyl, nitro, amino, straight or branched Ci-C₅ alkyl, or OR³ where.in R³ is hydrogen, trihalomethyl, straight or branched Ci-C₅ alkyl, or phenyl, and

X is hydrogen, straight or branched Ci-C₅ alkyl, or benzyl .

In a preferable embodiment,

R¹ and R² are each independently hydrogen, F, Cl, Br, I, -CF₃, -CCl₃, mesyl, nitro, amino, 'straight or branched Ci-C₃ alkyl, or OR³ wherein R³ is hydrogen, -CF₃, -CCl₃, straight or branched Ci-C₃ alkyl, or phenyl, and

X is hydrogen, straight or branched Ci-C₃ alkyl, or benzyl .

In a more preferably embodiment,

R¹ and R² are each independently hydrogen, F, Cl, methyl, or OR³ wherein R³ is methyl, and

X is hydrogen, methyl or benzyl.

Concrete examples of useful 4-methylimidazol-5- ylcarbonylguanidine derivatives include:

1) (2-phenyl-4-methyl-1Jf-imidazol-5- ylcarbonyl) guanidine; 2) (2- (2-methylphenyl) -4-methyl-lH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

3) (2- (3-methylphenyl) -4-methyl-liϊ-imidazol-5- ylcarbonyl) guanidine methanesulfonate;

4) (2- (4-methylphenyl) -4-methyl-lH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

5) (2- (2,3-dimethylphenyl) -4-methyl-lff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

6) (2- (2, 5-dimethylphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 7) (2- (3, 5-dimethylphenyl) -4-methyl-l/f-imidazol-5- ylcarbonyl) guanidine methanesulfonate; 8) (2- (2-methoxyphenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

9) (2- (3-methoxyphenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 10) (2- (4-methoxyphenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

11) (2- (2 , 3-dimethoxypheny1) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

12) (2- (2, 5-dimethoxyphenyl) -4-methyl-IJf-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

13) (2- (2-fluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

14) (2- (3-fluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine methanesulfonate; 15) (2- (4-fluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

16) (2- (2, 3-difluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

17) (2- (2, 5-difluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

18) (2- (3 , 5-difluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine methanesulfonate,-

19) (2- (2-chlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 20) (2-(3-chlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine; 21) (2- (4-chlorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

22) (2- (2, 3-dichlorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 23) (2- (2,5-dichlorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

24) (2- (3, 5-dichlorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine;

25) (2- (2-methoxy-5-chlorophenyl) -4 -methyl-IH- imidazol-5-ylcarbonyl) guanidine bismethanesulfonate;

26) (2- (2-methoxy-5-fluorophenyl) -4-methyl-IH- imidazol-5-ylcarbonyl) guanidine bismethanesulfonate;

27) (N-methyl-2-phenyl-4-methyl-IH-imidazol-5- ylcarbonyl) guanidine; 28) (N-methyl-2- (3-methylphenyl) -4-methyl-IH-imidazol- 5-ylcarbonyl) guanidine;

29) (N-methyl-2- (2-chlorophenyl) -4-methyl-IH-imidazol- 5-ylcarbonyl) guanidine;

30) (N-methyl-2- (3 -chlorophenyl) -4-methyl-IH-imidazol- 5-y1carbony1) guanidine;

31) (N-benzyl-2- (3-methylphenyl) -4-methyl-IH-imidazol- 5-y1carbony1) guanidine; and

32) (N-benzyl-2- (3-chlorophenyl) -4-methyl-IH-imidazol- 5-ylcarbonyl) guanidine . The 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention, represented by the Chemical Formula 1, may be used in the form of pharmaceutically acceptable salts . Useful are acid addition salts having pharmaceutically acceptable free acids. The free acids may be inorganic or organic. Examples of useful inorganic free acids include hydrochloric acid, bromic acid, nitric acid, sulfuric acid and phosphoric acid, with preference for hydrochloric acid. As organic acids, citric acid, lactic acid, maleic acid, fumaric acid, gluconic acid, methane sulfonic acid, acetic acid, gluconic acid, succinic acid, tartaric acid, 4-toluenesulfonic acid, galacturonic acid, embonic acid, glutamic acid or aspartic acid may be used, with methane sulfonic acid being preferred. Also, 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention, represented by Chemical Formula 1, may be in the form of conventionally producible salts, hydrates, and solvates thereof as well as pharmaceutically acceptable salts . Addition salts according to the present invention may be prepared using a conventional method. For example, they may be prepared by dissolving the compound of Chemical Formula 1 in a water-miscible organic solvent, such as acetone, methanol, ethanol or acetonitrile and adding an excess of organic acids or an excess of aqueous inorganic acid solutions so as to precipitate or crystallize salts . These addition salts may be obtained by distilling the solvent or excess of acids from the solution or by suctioning and filtering the precipitates .

Also, the present invention is concerned with a method for the preparation of novel 4-methylimidazol-5- ylcarbonylguanidine derivatives and pharmaceutically acceptable salts thereof.

In accordance with an embodiment of the present invention, the method for the preparation of 4- methylimidazol-5-ylcarbonylguanidine derivatives, as illustrated by the following Reaction- Scheme 1, comprises the reaction of a carboxylic acid derivative, having a leaving group (L) , of Chemical Formula 2 with guanidine of Chemical Formula 3 to afford 4-methylimidazol-5- ylcarbonylguanidine derivatives of Chemical Formula 1.

[Reaction Scheme 1]

2 1

wherein, R¹, R² and X are each as defined in Chemical Formula 1 and L is a leaving group. In Reaction Scheme 1, the carboxylic acid derivative of Chemical Formula 2, serving as a starting material, may^¬ be an ester derivative, an acyl halide derivative, an acid anhydride derivative or a carboxylic acid, depending on the leaving group L, with preference for an ester derivative or a carboxylic acid.

The leaving group is readily substitutable with guanidine in the carboxylic acid derivative of Chemical Formula 2. Examples of these leaving groups include a halogen atom, hydroxy, alkoxy, mesylate and tosylate. The leaving group useful in the present invention is a relatively stable, weakly alkaline molecule or ion, and can more readily leave from the carboxylic derivative of Chemical Formula 2 as it is of higher stability. When the carboxylic acid derivative is limited to an ester derivative, it may a general alkyl ester derivative, such as methyl ester, ethyl ester, etc., or an active ester derivative, such as p-nitrophenyl ester, N- hydroxysuccinimide ester, peptafluorophenyl ester, etc. These carboxylic acid derivatives may be readily prepared from carboxylic acids using a typical method well known in the art.

According to the method of the present invention, the carboxylic acid derivative (2) may be reacted with a stoichiometric amount of or an excess of guanidine in the presence of a suitable basic catalyst. In Reaction Formula 1,

1) When the carboxylic acid derivative (2) is an alkyl ester or an active ester, it is allowed to react with a stoichiometric amount of or an excess of guanidine in a suitable solvent to afford the compound (1) . Guanidine is preferably used in an amount of 1 ~ 10 equivalents with regard to the carboxylic acid derivative. The solvent suitable for this reaction may be selected from among alcohols, such as methanol, ethanol and isopropanol, ethers, such as tetrahydrofuran, 1,4-dioxane and 1, 2-dimethoxyethane, and dimethylformamide (DMF) , and mixtures thereof . The reaction is conducted at room temperature to the boiling point of the solvent used.

2) When the carboxylic acid derivative (2) is an acylhalide or an acid anhydride, it is allowed to react with an excess of guanidine in a suitable solvent or with guanidine in the presence of a base to afford the compound (1) . An inorganic base, such as sodium hydroxide, potassium hydroxide, sodium carbonate, etc., or an organic base, such as triethyl amine, pyridine, etc., may be suitable for use in this reaction. As a reaction solvent for use in this reaction, an aromatic hydrocarbon solvent such as benzene, toluene, etc., an ether solvent such as tetrahydrofuran, a halogenated hydrocarbon solvent such as dichloromethane, chloroform, etc., dimethylformamide (DMF), or combinations thereof may be used.

3) When the carboxylic acid derivative (2) is carboxylic acid, with the leaving group being hydroxy, the carboxylic acid compound (2a) , as illustrated in the following Reaction Scheme 2, is allowed to react with guanidine (3) in the presence of a condensing agent to afford the compound (1) :

[Reaction Scheme 2]

2a

wherein, R¹, R² and X are as defined in Chemical Formula 1, and the compound 2a is an compound of Chemical Formula 2.

According to this reaction, the carboxylic acid compound (2a) is reacted with a stoichiometric amount of or an excess of guanidine in the presence of a condensing agent in a suitable solvent to produce the compound of Chemical Formula 1. The reaction temperature may range from room temperature to the boiling point of the solvent used. The condensing agent useful in this reaction is preferably selected from among N₁ N-carbonyldiimidazole, dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-ethyl- 3 - (3-dimethylaminopropyl) carbodiimide, and diphenylphosphonylazide . As the reaction solvent, an ether solvent such as tetrahydrofuran, 1,4-dioxane, etc., an aromatic hydrocarbon solvent such as benzene, toluene, etc., a halogenated hydrocarbon solvent such as dichloromethane, chloroform, etc . , dimethylformamide (DMF) , or combinations thereof may be used.

In Reaction Scheme 1 or 2, when the substitutent R or X of the carboxylic acid derivative is affected by or affects the nucleophilic attack, the substituent needs to be protected by a protecting group. Hence, the method of the present invention may further comprise, as illustrated in the following Reaction Scheme 3 , protecting the substituent with a protecting group in advance of the nucleophilic reaction and deprotecting the substituent subsequent to the nucleophilic reaction.

[Reaction Scheme 3]

wherein,

R¹, R² and L are as defined in Reaction Scheme 1, m is a positive integer, representing the equivalent number of an addition salt associated with the compound, the compounds Ia, Ia' and Ib belong to Chemical Formula 1, and the compound 2b is an compound of Chemical Formula 2.

In Reaction Scheme 1 or 2, when the substituent X of Chemical Formula 1 is H, the method of the present invention may further comprise protecting the amine of the imidazole ring of Chemical Formula 2 with a protecting group in advance of reaction with guanidine 3 and deprotecting the amine subsequent to reaction with guanidine 3. The introduction of a protecting group into the nitrogen atoms may positively affect the yield of the reaction with guanidine. Because a base is used in the preparation of Compound 2b, the protecting group must be stable to base and may be preferably ethoxyethyl. As seen in Reaction Scheme 3, the Λ7-1-ethoxyethyl compound Ib may be prepared from the compound 2b using the method illustrated in Reaction Scheme 1 or 2.

Compound Ia, a compound of Chemical Formula 1 in which X is H, can be prepared by deprotecting compound Ib, a compound of Chemical Formula 1 in which X is 1-ethoxyethyl, through reaction with an inorganic acid, such as hydrochloric acid, sulfuric acid, etc., or an organic acid, such as acetic acid, 4-toluene sulfonic acid, methane sulfonic acid, etc. A solvent for use in this reaction is preferably a mixture of an alcohol such as methanol or ethanol and water when an inorganic acid is used. On the other, when an organic acid is used, a halogenated hydrocarbon, such as methylene chloride, an ether, such as tetrahydrofuran or 1,4-dioxane, acetonitrile, or acetone may be preferably used as a solvent. This reaction may be conducted within a temperature range from 0⁰C to the boiling point of the solvent used. In an alternative embodiment where an organic or inorganic acid is used, compound Ib is reacted to remove the protecting group 1-ethoxyethyl therefrom while producing an acid addition salt (Ia') of compound Ia in which X is H. More preferably, methane sulfonic acid is used to afford a one or two equivalents of the methane sulfonic acid addition salt of compound Ia. Below, a description is given of the preparation of the starting material carboxylic acid derivative . a) When the carboxylic acid derivative (2) used in Reaction Scheme 1 or 2 is ethyl ester (L = OC₂H₅) (2c) , as shown in the following Reaction Scheme 4, a phenylboronic acid compound 4 is allowed to undergo Suzuki-type coupling reaction with a 2-halo-4-methylimidazole compound 5 in the presence of a base and a catalyst to yield compound 2c.

[Reaction Scheme 4]

4 5 2c

wherein, R¹, R² and X are each as defined in Chemical Formula 1, Y is B(OH)₂, BCl₂, or BBr₂, Z is an halogen atom selected from among Cl, Br and I, or OSO₂CF₃, compound 2c is an compound of Chemical Formula 2.

The phenylboronic acid compound 4 may be a commercially available compound or may be prepared from phenyl according to a method known in the art .

The catalyst useful for Reaction Scheme 4 may be a metal catalyst examples of which include palladium, nickel, and platinum complexes, with palladium being preferred. As a palladium catalyst, Pd(PPh₃J₄, Pd-C, PdCl₂ (PPh₃) ₂ , Pd₂(dba)₃, PdCl₂ (dppf), [PdCKaIIyD]₂, Pd(OAc)₂ or PdCl₂ may be used.

In Reaction Scheme 4, a phosphine such as PPh₃, P- (o- tolyl)₃, or PBu₃, or a salt such as lithium chloride, lithium bromide or lithium iodide may be used as an additive in order to promote the reaction and increase the production yield.

The base is used in an amount of 1 to 3 equivalents for the Suzuki-type reaction in Reaction Scheme 4. Useful is a tertiary amine organic base such as triethylamine and isopropylethylamine, or an inorganic base such as sodium carbonate, barium carbonate, potassium hydroxide, sodium hydroxide, cesium carbonate, barium hydroxide, and the like. If an inorganic base is insoluble in an organic solvent, it may be added as a 0.5 to 4 M aqueous solution.

For the reaction in Reaction Scheme 4 , an ether such as tetrahydrofuran, 1,4-dioxane, 1, 2-dimethoxyethane, etc., an aromatic hydrocarbon such as benzene, toluene, xylene, etc., an alcohol such as methanol, ethanol, etc., DMF, acetonitrile, or ethylacetate may be used, alone or in combination, as a solvent. The reaction is conducted at a temperature ranging from room temperature to the boiling point of the solvent used.

Also, the 2-halo-4-methylimidazole compound 5 of Reaction Scheme 4 may be prepared, as illustrated in the following Reaction Scheme 5, from a commercially available 4-methylimidazole compound 6.

[Reaction Scheme 5]

H ° ^OC2H5 " zΛ I! V ° ^0C2Hs _ZΛ X Λr ° ^OC2H5 6 7 5 wherein, X is as defined in Chemical Formula 1, and Z is a halogen atom selected from among Cl, Br and I.

Through halogenation, the 4-methylimidazole compound 6 can be converted into the 2-halo-4-methylimidazole compound 7. The compound of Chemical Formula 7 can be prepared by reacting the compound of Chemical Formula 6 with a halogen molecule in an alcoholic solvent, such as acetic acid, methanol, etc., an ether solvent such as 1,4-dioxane, or water. Alternatively, the compound of Chemical Formula 6 is treated with a base such as lithium diisopropylamide (LDA) or n-Buli, followed by reaction with a halogen molecule in an ether solvent such as tetrahydrofuran or diethylether . Preferably, N-halosuccinimide may be used to prepare the compound of Chemical Formula 7. This reaction may be reacted in a solvent, such as an ether, e.g., tetrahydrofuran and 1,4-dioxane, DMF or acetonitrile, at a temperature ranging from 0⁰C to room temperature. The compound of Chemical Formula 5 can be obtained by reacting the compound of Chemical Formula 5 with a suitable alkyl halide depending on X in the presence of a base such as sodium hydride (NaH) , potassium carbonate, sodium carbonate, etc. For this reaction, an ether such as tetrahydrofuran, acetonitrile, or DMF may be used, with a reaction temperature ranging from 0⁰C to the boiling point of the solvent used.

When X is 1-ethoxyethyl, the compound of Chemical Formula 5 can be obtained by reacting the compound of Chemical Formula 7 with ethyl vinylether in the presence of an acid catalyst . This reaction may be conducted in a halogenated hydrocarbon such as dichloromethane, or acetonitrile at a temperature ranging from O⁰C to room temperature.

b) When L is -OH, as shown in Reaction Scheme 2, the starting material carboxylic acid derivative 2a can be obtained from the ester derivative 2c through hydrolysis in the presence of a base.

c) When the starting material 2 in Reaction Scheme 1 is a derivative other than ethyl ester, it can be prepared as illustrated in Reaction Scheme 4 or can be synthesized from the carboxylic acid derivative (2a) using a typical method. Also, the present invention pertains to a cardioprotective pharmaceutical composition for use in the prophylaxis and treatment of ischemic heart diseases, comprising the 4-methylimidazol-5-ylcarbonylguanidine derivatives or pharmaceutically acceptable salts thereof as an active ingredient.

The NHE-I inhibitor has been proven to improve myocardial contractility and metabolic status, and to reduce arrhythmia, apoptosis, necrosis, and intracellular overload of Na⁺ and Ca, indicating that it has cardioprotective activity against ischemic/reperfusional injury [Karmazyn, M (2002) Science & Medcine : 18-26] .

Compounds of the present invention and pharmaceutically acceptable salts thereof are proven to have highly potent inhibitory activity against NHE-I in human NHE-I expressed cells, highly promote the functional recovery (LVDP) of the isolated ischemic/reperfusional rat Langendorff heart model, and significantly reduce myocardiac infarction rates in rat in vivo ischemic heart model .

Having potent inhibitory activity against NHE-I and excellent protective effects on the heart against ischemia/reperfusion in in vivo and in vitro models, therefore, the novel 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention or pharmaceutically acceptable salts thereof can be used for the prophylaxis and treatment of ischemic cardiac diseases such as myocardiac infarction, arrhythmia, and angina pectoris and can serve as a cardioprotective agent applicable for coronary reperfusion therapy with coronary artery bypass, percutaneous transluminal coronary angioplasty, and/or thrombolytics for myocardiac infarction.

The compound of Chemical Formula 1 according to the present invention or a pharmaceutically acceptable salt thereof may be clinically administered in oral or non-oral ^'forms. It is usually formuated in combination with a diluent or excipient, such as a filler, a thickening agent, a binder, a wetting agent, a disintegrant, a surfactant, etc. Solid agents intended for oral administration of the compound of the present invention may be in the form of tablets, pills, powders, granules, capsules, troches, and the like. These solid agents are formulated in combination with at least one excipient such as starch, calcium carbonate, sucrose, lactose, or gelatine. Besides, a lubricant such as magnesium stearate, talc, and the like may be added, as well . Liquid agents intended for oral administration include suspensions, internal use solutions, emulsion, syrups, and the like. In addition to a simple diluent such as water or liquid paraffin, various excipients, such as wetting agents, sweetening agents, aromatics, preservatives, and the like may be contained in the liquid agents for the oral administration of the compound of the present invention. Also, the compound of the present invention may be administered via a non-oral route. For this, sterile aqueous solutions, non-aqueous solvents, suspensions, emulsions, lyophilics, suppositories, and the like may be used. Injectable propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and esters such as ethyl olate may be suitable for non-aqueous solvents and suspensions . The basic materials of suppositories include witepsol, macrogol, tween 61, cacao paper, laurin paper, glycerol, and gelatine.

Depending on the conditions of patients, including age, body weight, sex, administration route, health state, and disease severity, the administration dose of the compound of the present invention to humans may vary. Typically, the compound of the present invention is administered at a dose from 0.1 to 1,000 mg a day for an adult weiging 70 kg, and preferably at a dose from 1 to 500 mg a day. The compound may be administered in a single dose or in divided doses per day according to the instruction of the physician or pharmacist. [Mode for Invention]

A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed as the limit of the present invention.

PREPARATION EXAMPLE 1: Preparation of 2-Bromo-4- Methyl-lIf-Imidazole-5-Carboxylic acid Ethyl ester

To a solution of ethyl 4-methyl-5-imidazole carboxylate (10 g, 64.86 mmol) in acetonitrile (150 ml) was added W-bromosuccinimide (12.7 g, 71.35 mmol) at 0⁰C and the temperature was slowly elevated to the room temperature before stirring the solution for 16 hrs . After the completion of the reaction, the reaction mixture was added with water, extracted twice with ethyl acetate and washed with brine. The extract was dried over magnesium sulfate (MgSO₄) and filtered, followed by the vacuum concentration of the filtrate. The purification of the concentrate through silica gel column chromatography (hexene:ethylacetate=2 : 1) afforded the title compound as a white solid (9.5 g, 63%).

¹H-NMROOO MHz, CDCl₃) σ 1.34 (t, 3H), 2.53 (s, 3H), 4.34 (q, 2H); MS 234 (M⁺) . PREPARATION EXAMPLE 2: Preparation of N-(I- Ethoxyethyl) ^-Bromo^-Methyl-IΗ-Imidazole-S-Carboxylic acid Ethyl ester

To a solution of ethyl vinylether (6.6 ml, 68.65 mmol) in methylene chloride (CH₂Cl₂, 20 ml) was added trifluoroacetic acid (3 mmol%) at 0⁰C at which reaction was conducted for 5 min, followed by mixing with a solution of the compound (8 g, 34.33 mmol) of Preparation Example 1 in CH₂Cl₂OO ml) . Reaction at room temperature for 3 hrs was precedent to the addition of water to the reaction mixture which was then extracted twice with CH₂Cl₂ and washed with saturated brine . The extract was dried over magnesium sulfate (MgSO₄) and filtered, followed by the vacuum concentration of the filtrate. The purification of the concentrate through silica gel column chromatography (hexene:ethylacetate=2 : 1) afforded the title compound as a colorless oil (9.8 g, 93%).

¹H-NMROOO MHz, CDCl₃) σ 5.68(q, IH), 4.37 (q, 2H), 3.44-3.35(m, 2H), 2.71(s, 3H), 1.67 (d, 3H), 1.39(t, 3H), 1.20 (t, 3H) ;

MS 304 (M⁺) .

PREPRARATION EXAMPLE 3: Preparation of 2V-(I- Ethoxyethyl) ^-Aryl^-methyl-lH-Imidazole-S-Carboxylic acid Ethyl ester Preparation Example 3-1: N- (1-Ethoxyethyl) -2-Phenyl-4- Methyl-l.H-Imidazole-5-Carboxylic acid Ethyl ester

The compound obtained in Preparation Example 2 (600 mg, 1.97 mmol) was dissolved, together with Pd(PPh₃) ₄ (68 mg, 3 mmol%, 0.059 mmol) and phenylboronic acid (408 mg , 3.34 mmol) in toluene (7 ml) . To the solution was added an aqueous solution of 2M potassium carbonate (K₂CO₃, ImI) , and the solution mixture was heated under reflux with stirring for 16 hrs. After the completion of reaction, the reaction mixture was added with an aqueous 2 N sodium hydroxide (NaOH) solution, extracted twice with ethyl acetate, and washed with brine. The extract was dried over MgSO₄ and filtered, followed by the vacuum concentration of the filtrate. The purification of the concentrate through silica gel column chromatography (hexene : ethylacetate=2 : 1) afforded the title compound as a pale yellow oil (560 mg, 94%) .

¹H-NMROOO MHz, CDCl₃) σ 1.08 (t, 3H, J = 7.0 Hz), 1.40(t, 3H, J = 7.1 Hz), 1.71(d, 3H, J = 6.2 Hz), 2.79(s, 3H), 3.19(m, 2H), 4,41(q, 2H, J = 7.1 Hz), 5.47(q, 2H, J = 6.2 Hz) , 7.45 (m, 5H) ; MS 303 (M⁺) . Preparation Example 3-2: N- (1-Ethoxyethyl) -2- (2- methylphenyl) -4-methyl-lH-imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2-methylphenyl boronic acid (201 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (230 mg, 74%) .

¹H-NMR(SOO MHz, CDCl₃) σ l.ll(t, 3H, J = 7.1 Hz), 1.39(t, 3H, J = 7.2 Hz), 1.62 (d, 3H, J = 6.5 Hz), 2.19(s, 3H), 2.78(S, 3H), 3.25(q, 2H, J = 7.1 Hz), 4.40(q, 2H, J^" = 7.2 Hz), 5.14 (q, IH, J = 6.5 Hz), 7.20-7.39 (m, 4H);

MS 316 (M⁺) .

Preparation Example 3-3: Preparation of Af-(I- ethoxyethyl) -2- (3-methylphenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3 -methylphenyl boronic acid (201 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (240 mg, 77%) . 1H-NMROOO MHz, CDCl₃) σ 1.08 (t, 3H, J = 7.1 Hz), 1.39(t, 3H, J = 7.1 Hz), 1.71 (d, 3H, J = 6.2 Hz), 2.38(s, 3H), 2.78(s, 3H), 3.19(q, 2H, J = 7.1 Hz), 4.40(q, 2H, J = 7.1 Hz), 5.50 (q, IH, J= 6.2 Hz), 7.20-7.39 (m, 4H); MS 316 (M⁺) . Preparation Example 3-4: Preparation of N-(I- ethoxyethyl) -2- (4-methylphenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 4-methylphenyl boronic acid (201 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (245 mg, 79%) .

¹H-NMROOO MHz, CDCl₃) σ 1.07 (t, 3H, J = 7.0 Hz),

1.39(t, 3H, J = 7.2 Hz), 1.71(d, 3H, J = 6.3 Hz), 2.39(s, 3H), 2.78(s, 3H), 3.18(q, 2H, J = 7.0 Hz), 4.40(q, 2H, J =

7.2 Hz), 5.47(q, IH, J = 6.3 Hz), 7.23(d, 2H, J = 7.8 Hz),

7.35 (d, 2H, J= 7.8 Hz) ;

MS 316 (M⁺) .

Preparation Example 3-5: Preparation of N-(I- ethoxyethyl) -2- (2, 3-dimethylphenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2, 3-dimethylphenyl boronic acid (369 mg, 2.46 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (483 mg, 89%) .

¹H-NMROOO MHz, CDCl₃) σ l.ll(t, 3H, J = 6.9 Hz) ,

1.39(t, 3H, J = 6.9 Hz) , 1.60(d, 3H, J = 6.0 Hz) , 2.04(s, 3H), 2.29(s, 3H), 2.78(s, 3H) , 3.33(q, 2H, J = 6.9 Hz) , 4.38(q, 2H, J = 6.9 Hz) , 5.12 (q, IH, J = 6.0 Hz) , 7.10- 7.24 (m, 3H) ;

MS 330 (M⁺) .

Preparation Example 3-6: Preparation of JV-(I- ethoxyethyl) -2- (2, 5-dimethylphenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2, 5-dimethylphenyl boronic acid (369 mg, 2.46 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (402 mg, 74%) .

¹H-NMROOO MHz, CDCl₃) σ 1.11 (t, 3H, J - 7.0 Hz) ,

1.39(t, 3H, J = 7.1 Hz) , 1.62(d, 3H, J = 6.2 Hz) , 2.13(s, 3H) , 2.31(S, 3H) , 2.77(s, 3H) , 3.15-3.35(m, 2H) , 4.40(q, 2H,

J = 7.1 Hz) , 5.15 (q, IH, J = 6.2 Hz) , 7.01 (s, IH) , 7.14(s,

2H) ;

MS 330 (M⁺) .

Preparation Example 3-7 : N-(I-ethoxyethyl) -2- (3 , 5- dimethylphenyl) -4-methyl-IH-imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3, 5-dimethylphenyl boronic acid (221 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (249 tng, 77%) .

¹H-NMROOO MHz, CDCl₃) σ 1.03 (t, 3H, J = 7.3 Hz), 1.39(t, 3H, J = 6.9 Hz), 1.71(d, 3H, J = 6.1 Hz), 2.34(s, 6H), 2.78(s, 3H), 3.19(q, 2H, J = 7.3 Hz), 4.40(q, 2H, J = 6.9 Hz), 5.50 (q, IH, J= 6.1 Hz), 7.07 (m, 3H); MS 330 (M⁺) .

Preparation Example 3-8: Preparation of Af-(I- ethoxyethyl) -2- (2-methoxyphenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2-methoxyphenyl boronic acid (374 mg, 2.46 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (316 mg, 58%) . 1H-NMROOO MHz, CDCl₃) σ 1.05 (t, 3H, J = 6.9 Hz), 1.39 (t, 3H, J = 6.9 Hz), 1.65 (d, 3H, J = 5.4 Hz), 2.78(s, 3H), 3.13 (m, 2H), 3.76(s, 3H), 4.40(q, 2H, J = 6.9 Hz), 5.14 (q, IH, J = 5.4 Hz), 6.93 (d, IH, J = 8.4 Hz), 7.02 (dd, IH, J= 7.5, 7.5 Hz), 7.39-7.46(m, 2H); MS 332 (M⁺) .

Preparation Example 3-9: Preparation of N-(I- ethoxyethyl) -2- (3-methoxyphenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3-methoxyphenyl boronic acid (224 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (227 mg, 70%) . 1H-NMROOO MHz, CDCl₃) σ 1.08 (t, 3H, J = 7.1 Hz),

1.39 (t, 3H, J = 7.1 Hz), 1.71(d, 3H, J = 6.2 Hz), 2.78(s, 3H), 3.19(m, 2H), 3.83(s, 3H, ) , 4.40(q, 2H, J = 7.1 Hz), 5.50 (q, IH, J = 6.2 Hz), 6.99-7.06(m, 3H), 7.33(dd, IH, J = 7.9, 7.9 Hz) ; MS 332 (M⁺) .

Preparation Example 3-10: Prepartion of N-(I- ethoxyethyl) -2- (4-methoxyphenyl) -4 -methyl-IH-imidazole-5- carboxylic acid ethyl ester The same procedure as in Preparation Example 3-1 was carried out, with the exception that 4-methoxyphenyl boronic acid (224 mg, 1.48 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (264 mg, 81%) . 1H-NMROOO MHz, CDCl₃) σ 1.08 (t, 3H, J = 6.9 Hz), 1.40(t, 3H, J = 7.2 Hz), 1.70(d, 3H, J = 6.3 Hz), 2.77(s, 3H), 3.20(m, 2H), 3.85(s, 3H), 4.38(q, 2H, J = 7.2 Hz), 5.46 (q, IH, J = 6.3 Hz), 6.95 (dd, 2H, J = 2.1, 7.2 Hz), 7.40 (dd, 2H, J= 2.1, 7.2 Hz);

MS 316 (M⁺) . Preparation Example 3-11: Preparation of N-(I- ethoxyethyl) -2- (2, 3-dimethoxyphenyl) -4-methyl-IH-imidazole- 5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2, 3-dimethoxyphenyl boronic acid (447 mg, 2.46 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (466 mg, 79%) .

¹H-NMROOO MHZ, CDCl₃) σ l.04(br, 3H) , 1.40(t, 3H, J = 6.9 Hz) , 1.67 (d, 3H, J = 6.0 Hz) , 2.79 (s, 3H) , 3.16 (br, 2H) ,

3.61(s, 3H) , 3.91(s, 3H) , 4.39(q, 2H, J = 6.9 Hz) , 5.20(q, IH, J = 6.0 Hz) , 7.00(m, 2H) , 7.11 (dd, IH, J = 7.8, 7.8 Hz) ;

MS 362 (M⁺) .

Preparation Example 3-12: Preparation of N-(I- ethoxyethyl) -2- (2, 5-dimethoxyphenyl) -4-methyl-IJf-imidazole-

5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2, 5-dimethoxyphenyl boronic acid (447 mg, 2.46 mmol) was used instead of phenyl boronic acid, to afford the object compound as an oil (350 mg, 69%) .

¹H-NMROOO MHz, CDCl₃) σ 1.06(t, 3H, J = 6.9 Hz) ,

1.39(t, 3H, J = 7.2 Hz) , 1.68(br, 3H) , 2.78(s, 3H) , 3.15 (br, 2H) , 3.70(S, 3H) , 3.77 (s, 3H) , 4.38 (m, 2H) , 5.16 (q, IH) , 6 . 86 (d, IH , J = 9 . 3 Hz ) , 6 . 95 (dd, IH , J = 3 . 0 , 9 . 3 Hz ) , 6 . 98 (d, IH , J = 3 . 0 Hz ) ; MS 290 (M⁺- 72 ) .

Preparation Example 3-13: Preparation of N-(I- ethoxyethyl) -2- (2-fluorophenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester

The compound obtained in Preparation Example 2 (500 mg, 1.64 mmol) was dissolved, together with Pd(PPh₃J₄ (152 mg, 8 mmol%) and 2-fluorophenylboronic acid (344 mg , 2.46 mmol) in toluene (10 ml) . To the solution was added 2 M sodium carbonate (Na₂CO₃, 2.1 ml) and anhydrous lithium chloride (208 mg, 4.92 mmol), and the solution mixture was heated under reflux with stirring for 16 hrs . After the completion of reaction, the reaction mixture was concentrated in a vacuum to remove ethanol, and the residue was added with an aqueous 2 N sodium hydroxide (NaOH) solution, subjected twice to extraction with ethyl acetate, and washed with brine. The extract was dried over MgSO₄ and filtered, followed by the vacuum concentration -of the filtrate. The purification of the concentrate through silica gel column chromatography (hexene : ethylacetate=2 : 1) afforded the title compound as an oil (311mg, 0.97mmol, 60%) .

¹H-NMROOO MHz, CDCl₃) σ 1.07 (t, 3H, J = 7.2 Hz), 1.40(t, 3H, J = 6.9 Hz), 1.70(d, 3H, J = 6.0 Hz), 2.79(s, 3H), 3.18 (m, 2H), 4.40 (q, 2H, J = 6.9 Hz), 5.23 (q, IH, J = 6 . 0 Hz ) , 7 . 14 (dd, IH , J = 8 . 1 , 9 . 3 Hz ) , 7 . 23 (m, IH) , 7 . 48 (m, 2H) ;

MS 320 (M⁺) .

Preparation Example 3-14: Preparation of N-(I- ethoxyethyl) -2- (3-fluorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that phenyl boronic acid (206 mg, 1.48 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (260 mg, 83%) .

¹H-NMROOO MHz, CDCl₃) σ 1.10(t, 3H, J = 6.9 Hz),

1.41(t, 3H, J = 7.2 Hz), 1.71(d, 3H, J = 6.3 Hz), 2.79(s,

3H), 3.21(q, 2H, J = 6.9 Hz), 4.40(q, 2H, J = 7.2 Hz), 5.47(q, IH, J = 6.3 Hz), 7.16 (m, IH), 7.23-7.28(m, 2H),

7.40 (m, IH) ;

MS 320 (M⁺) .

Preparation Example 3-15: Preparation of AJ-(I- ethoxyethyl) -2- (4-fluorophenyl) -4-methyl-lH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 4-fluorophenyl boronic acid (206 mg, 1.48 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (210 mg, 67%) . ¹H-NMROOO MHz, CDCl₃) σ 1.09(t, 3H, J = 6.9 Hz), 1.40(t, 3H, J = 7.2 Hz), 1.69(d, 3H, J = 6.3 Hz), 3.20(m, 2H), 4.40(q, 2H, J = 7.2 Hz), 5.42(q, IH, J = 6.3 Hz), 7.13 (ra, 2H) , 7.47 (m, 2H) ; MS 320 (M⁺) .

Preparation Example 3-16: Preparation of N-(I- ethoxyethyl) -2- (2, 3-difluorophenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester The same procedure as in Preparation Example 3-13 was carried out, with the exception that 3-fluorophenyl boronic acid (206 mg, 1.48 mmol) was used instead of 2- fluorophenylboronic acid, to afford the object compound as an oil (260 mg, 83%) . 1H-NMR(SOO MHz, CDCl₃) σ 1.09(t, 3H, J = 7.2 Hz),

1.39(t, 3H, J = 7.2 Hz), 1.70(d, 3H, J = 6.0 Hz), 2.79(s, 3H), 3.21(m, 2H), 4.40(q, 2H, J = 7.2 Hz), 5.23(q, IH, J = 6.0 Hz), 7.19(m, IH), 7.25-7.31(m, 2H); MS 338 (M⁺) .

Preparation Example 3-17: Preparation of AJ-(I- ethoxyethyl) -2- (2, 5-difluorophenyl) -4-methyl-lff-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-13 was carried out, with the exception that 2, 5-difluorophenyl boronic acid (388 mg, 2.46 mmol) was used instead of 2- fluorophenylboronic acid, to afford the object compound as an oil (147 mg, 27%) .

¹H-NMROOO MHz, CDCl₃) σ 1.09(t, 3H, J = 7.2 Hz), 1.41(t, 3H, J = 7.2 Hz), 1.70(d, 3H, J = 6.3 Hz), 2.79(s, 3H), 3.18 (q, 2H, J = 7.2 Hz), 4.40(q, 2H, J = 7.2 Hz), 5.24 (q, IH, J= 6.3 Hz), 7.10-7.17 (m, 2H), 7.25 (m, IH); MS 338 (M⁺) .

Preparation Example 3-18: Preparation of N- (1- ethoxyethyl) -2- (3, 5-difluorophenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3, 5-difluorophenyl boronic acid (388 mg, 2.46 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil

(336 mg, 61%) .

¹H-NMROOO MHz, CDCl₃) σ 1.15(t, 3H, J = 7.0 Hz), 1.40(t, 3H, J = 7.1 Hz), 1.71(d, 3H, J = 6.2 Hz), 2.78(s, 3H), 3.23(q, 2H, J = 7.0 Hz), 4.40(q, 2H, J = 7.1 Hz), 5.48 (q, IH, J= 6.2 Hz), 6.88 (m, IH), 7.06(m, 2H); MS 338 (M⁺) .

Preparation Example 3-19: Preparation of JV-(I- ethoxyethyl) -2- (2-chlorophenyl) -4-methyl-Iff-imidazole-5- carboxylic acid ethyl ester The same procedure as in Preparation Example 3-13 was carried out, with the exception that 2-chlorophenyl boronic acid (344 mg, 2.46 mmol) was used instead of 2- fluorophenylboronic acid, to afford the object compound as an oil (398 mg, 72%) .

¹H-NMROOO MHz, CDCl₃) σ 1.10 (t, 3H, J = 6.6 Hz) , 1.39(t, 3H, J = 6.9 Hz) , 1.66(br, 3H) , 2.79(s, 3H) , 3.21(br, 2H) , 4.40(m, 2H) , 5.10 (q, IH, J = 6.0 Hz) , 7.35-7.49(m, 4H) ;

MS 336 (M⁺) .

Preparation Example 3-20: Preparation of N-(I- ethoxyethyl) -2- (3-chlorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3-chlorophenyl boronic acid (231 mg, 1.48 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (275 mg, 83%) .

¹H-NMROOO MHz, CDCl₃) σ l.ll(t, 3H, J = 7.1 Hz),

1.41(t, 3H, J = 7.2 Hz), 1.72(d, 3H, J = 6.1 Hz), 2.79(s, 3H), 3.22 (q, 2H, J = 7.1 Hz), 4.40(q, 2H, J = 7.2 Hz),

5.47(q, IH, J = 6.1 Hz), 7.35-7.53(m, 3H), 7.55(d, IH, J =

1.8 Hz) ;

MS 336 (M⁺) . Preparation Example 3-21: Preparation of AZ-(I- ethoxyethyl) -2- (4-chlorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 4-chlorophenyl boronic acid (231 mg, 1.48 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (254 mg, 77%) .

¹H-NMR(SOO MHz, CDCl₃) σ 1.09(t, 3H, J = 6.9 Hz), 1.40(t, 3H, J = 7.2 Hz), 1.70(d, 3H, J = 6.3 Hz), 2.77(s, 3H), 3.20 (m, 2H), 4.40(m, 2H), 5.43 (q, IH, J = 6.3 Hz), 7.43 (m, 4H) ;

MS 336 (M⁺) .

Preparation Example 3-22: Preparation of AJ-(I- ethoxyethyl) -2- (2, 3-dichlorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-13 was carried out, with the exception that 2, 3-dichlorophenyl boronic acid (469 mg, 2.46 mmol) was used instead of 2- fluorophenylboronic acid, to afford the object compound as an oil (257 mg, 42%) .

¹H-ISIMROOO MHz, CDCl₃) σ 1.10(br, .3H), 1.39(t, 3H, J = 7.2 Hz) , 1.64(br, 3H) , 2.78(s, 3H) , 3.21(br, 2H) , 4.40(q, 2H, J = 7.2 Hz) , 5.09(q, IH, J = 6.3 Hz) , 7.29 (m, 2H) , 7.58(d, IH, J = 6.9 Hz) ;

MS 370 (M⁺) . Preparation Example 3-23: Preparation of N-[I- ethoxyethyl) -2- (2, 5-dichlorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester The same procedure as in Preparation Example 3-13 was carried out, with the exception that 2, 5-dichlorophenyl boronic acid (469 mg, 2.46 mmol) was used instead of 2- fluorophenylboronic acid, to afford the object compound as an oil (271 mg, 45%) . 1H-NMROOO MHz, CDCl₃) σ 1.14 (t, 3H, J = 6.9 Hz),

1.40(t, 3H, J= 6.9 Hz), 1.68(br, 3H), 2.78(s, 3H), 3.24(br, 2H), 4.40(q, 2H, J = 6.9 Hz), 5.11(q, IH, J = 6.0 Hz), 7.40 (m, 3H);

MS 370 (M⁺) .

Preparation Example 3-24: Preparation of AJ-(I- ethoxyethyl) -2- (3, 5-dichlorophenyl) -4-methyl-IH-imidazole-5- carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 3, 5-dichlorophenyl boronic acid (469 mg, 2.46 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil

(513 mg, 84%) .

¹H-NMROOO MHz, CDCl₃) σ 1.14 (t, 3H, J = 7.1 Hz) , 1.40(t, 3H, J = 7.1 Hz) , 1.71 (d, 3H, J = 6.2 Hz) , 2.78(s, 3H) , 3.25(q, 2H, J = 7.1 Hz) , 4.40(q, 2H, J^" = 7.1 Hz) , 5.46(q, IH, J = 6.2 Hz) , 7.42-7.44 (m, 3H) ; MS 298 (M⁺-72) .

Preparation Example 3-25:' Preparation of IV-(I- ethoxyethyl) -2- (2-methoxy-5-chlorophenyl) -4-methyl-IH- imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2-methoxy-5- chlorophenyl boronic acid (458 mg, 2.46 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (349 mg, 58%) .

¹H-NMROOO MHz, CDCl₃) σ 1.08 (t, 3H, J = 7.2 Hz) ,

1.39(t, 3H, J = 6.9 Hz) , 1.68(d, 3H, J = 6.3 Hz) , 2.78(s, 3H) , 3.16(br, 2H) , 3.76(s, 3H) , 4.36(q, 2H, J = 6.9 Hz) ,

5.10 (q, IH, J = 6.3 Hz) , 6.87 (d, IH, J = 8.7 Hz) , 7.37-

7.42 (m, 2H) ;

MS 367 (M+l)⁺.

Preparation Example 3-26: Preparation of JV-(I- ethoxyethyl) -2- (2-methoxy-5-fluorophenyl) -4-methyl-IH- imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 3-1 was carried out, with the exception that 2-methoxy-5- fluorophenyl boronic acid (251 mg, 1.48 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (219 mg, 64%) .

¹H-ISIMROOO MHz, CDCl₃) σ 1.07 (t, 3H, J = 7.1 Hz), 1.39(t, 3H, J = 7.1 Hz), 1.67(d, 3H, J = 6.3 Hz), 2.78(s, 3H), 3.16 (br, 2H), 3.74 (s, 3H), 4.40 (q, 2H, J = 7.1 Hz), 5.14 (q, IH, J = 6.3 Hz), 6.87 (dd, IH, J = 4.4, 8.9 Hz), 7.09-7.19 (m, 2H) ; MS 350 (M⁺) .

PREPARATION EXAMPLE 4: Preparation of iV-Methyl-2- Bromo-4-Methyl-lH-Imidazole-5-Carboxylic acid Ethyl ester

A solution of 2-bromo-4-methyl-lH-imidazole-5- carboxylic acid ethyl ester (1.0 g, 4.29 mmol) in dimethylformamide (DMF, 30 ml) was cooled to O⁰C, added with 60% sodium hydride (NaH, 343 mg, 8.58 mmol) and stirred for 30 min. Iodomethane (0.8 ml, 12.87 mmol) was slowly added in droplets to the resulting solution which was then heated from 0⁰C to room temperature with stirring for 4 hrs and added with water, followed by extraction with ethyl acetate. The extract was dried over MgSO₄, filtered and concentrated in a vacuum. The purification of the concentrate thus obtain through silica gel column chromatography

(hexane : ethyl acetate=5:l) afforded the object compound as a white solid (693 mg, 2.81 mmol, 65%) . 1H-NMROOO MHz, CDCl₃) σ 1.38 (t, 3H, J = 7.1 Hz) ,

2.46(s, 3H) , 3.88(s, 3H) , 4.33(q, 2H, J = 7.1 Hz); MS 246 (M⁺) .

PREPARATION EXAMPLE 5: Preparation of N-Methyl-2-Aryl- 4-methyl-lH-Imidazole-5-Carboxylic acid Ethyl ester

Preparation Example 5-1: Preparation of N-methyl-2- phenyl-4-methyl-llf-imidazole-5-carboxylic acid ethyl ester

The compound obtained in Preparation Example 4 (230 mg, 0.93 mmol) was dissolved, along with Pd(PPh₃J₄ (32 mg, 3 mmol%, 0.028 mmol) and phenylboronic acid (193 mg, 1.58 mmol) , in toluene (5 ml) . To the solution was added 2 M K₂CO₃ (0.6 ml), and the solution mixture was heated under reflux with strring for 16 hrs . After the completion of reaction, the reaction mixture was added with an aqueous 2 N sodium hydroxide (NaOH) solution, extracted twice with ethyl acetate, and washed with brine . The extract was dried over MgSO₄ and filtered, followed by the vacuum concentration of the filtrate. The purification of the concentrate through silica gel column chromatography (hexane:ethylacetate=5:l) afforded the object compound as an oil (231 mg, 60%) .

¹H-NMROOO MHz, CHDCl₃) σ 1.41 (t, 3H, J = 7.1 Hz), 2.54(s, 3H), 3.88(s, 3H), 4.35(q, 2H, J = 7.1 Hz), 7.49 (m, 3H), 7.59(m, 2H);

MS 244 (M⁺) . Preparation Example 5-2: Preparation of iV-methyl-2- (3- methylphenyl) -4-methyl-lΗ^'-imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 5-1 was conducted with the exception that 3-methylphenylboronic acid (187 mg, 1.38 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (238 mg, 67%) .

¹H NMR(300 MHz, CDCl₃) σ 1.37 (t, 3H, J = 7.1 Hz), 2.54(s, 3H), 3.88(s, 3H), 4.36(q, 2H, J = 7.1 Hz), 7.25- 7.55 (m, 4H) ;

MS 258 (M⁺) .

Preparation Example 5-3: Preparation of Λf-methyl-2- (2- chlorophenyl) -4-methyl-lJf-imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 5-1 was conducted with the exception that 2-chlorophenylboronic acid (285 mg, 1.82 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (239 mg, 71%) . 1H-NMROOO MHz, CDCl₃) σ 1.41 (t, 3H, J = 7.2 Hz),

2.55(s, 3H), 3.69(s, 3H), 4.37(q, 2H,^" J = 7.2 Hz), 7.36- 7.51(m, 4H) ;

MS 278 (M⁺) .

Preparation Example 5-4: N-methyl-2- (3 -chlorophenyl) -

4-methyl-lH-imidazole-5-carboxylic acid ethyl ester The same procedure as in Preparation Example 5-1 was conducted with the exception that 3-chlorophenylboronic acid (285 mg, 1.82 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (260 mg, 77%) . 1H-NMROOO MHz, CDCl₃) σ 1.41 (t, 3H, J = 7.2 Hz),

2.53(s, 3H), 3.89(s, 3H), 4.37(q, 2H, J = 7.2 Hz), 7.43- 7.46 (m, 3H), 7.61(d, IH, J= 1.8 Hz); MS 278 (M⁺) .

PREPARATION EXAMPLE 6: Preparation of N-Benzγl-2- Bromo-4-Methyl-lE-Imidazole-5-Carboxylic acid Ethyl ester

After the addition of K₂CO₃(1.05 g, 7.63 mmol) thereto, a solution of 2-bromo-4-methyl-lH-imidazole-5-carboxylic acid ethyl ester (1.2 g, 5.08 mmol) in DMF (45 ml) was stirred at room temperature for 30 min and mixed with benzyl chloride (0.7 ml, 6.10 mmol). The reactants were induced to react therewith by elevating the temperature to 120°C with stirring for 8 hrs. After the completion of reaction, the reaction mixture was cooled and added with water. Then, extraction with ethyl acetate was precedent to drying over MgSO₄, followed by filtration and vacuum concentration. Through silica gel column chromatography (hexane : ethyl acetate = 8:1), the concentrate thus obtained was purified to the object compound as a white solid (1.06 g, 3.28 mmol, 65%) . ¹H-NMROOO MHz, CDCl₃) σ 1.40 (t, 3H, J = 7.1 Hz) , 2.48(s, 3H) , 4.37(q, 2H, J = 7.1 Hz) , 5.17(s, 2H) , 7.03 (m, 2H) , 7.32 (m, 3H) ;

MS 323 (M⁺) .

PREPARATION EXAMPLE 7: Preparation of Λ/-Benzyl-2-Aryl- 4-Methyl-lH-Imidazole-5-Carboxylic acid Ethyl ester

Preparation Example 7-1: Preparation of JV-benzyl-2- (3- methylphenyl) -4-methyl-lJ^cf-imidazole-5-ca.rboxylic acid ethyl ester

The compound obtained in Preparation Example 6 (600 mg, 1.86 mmol) was dissolved, along with Pd(PPh₃J₄ (65 mg, 3 mmol%, 0.056 mmol) and 3-methylphenylboronic acid (429 mg, 3.16 mmol), in toluene (10 ml) . To the ' solution was added 2 M K₂CO₃ (1.8 ml), and the solution mixture was heated under reflux with stirring for 16 hrs . After the completion of reaction, the reaction mixture was added with an aqueous 2 N sodium hydroxide (NaOH) solution, extracted twice with ethyl acetate, and washed with brine. The extract was dried over MgSO₄ and filtered, followed by the vacuum concentration of the filtrate. The purification of the concentrate through silica gel column chromatography. (hexane:ethylacetate=5 : 1) afforded the object compound as an oil (266 mg, 45%) . ¹H-ISIMROOO MHz, CDCl₃) σ 1.25 (t, 3H, J = 7.1 Hz) , 2.56(s, 3H) , 4.22(q, 2H, J = 7.1 Hz) , 5.57(s, 2H) , 6.94 (m, 2H) , 7.24-7.41 (m, 6H) , 7.55 (d, IH, J = 1.5 Hz) ;

MS 334 (M⁺) . Preparation Example 7-2: Preparation of iV-Benzyl-2- (3- chlorophenyl) -4-methyl-lg-imidazole-5-carboxylic acid ethyl ester

The same procedure as in Preparation Example 7-1 was conducted with the exception that 3-chlorophenylboronic acid (494 mg, 3.16 mmol) was used instead of phenylboronic acid, to afford the object compound as an oil (282 mg, 44%) .

¹H-NMROOO MHz, CDCl₃) σ 1.26(t, 3H, J = 7.2 Hz), 2.41(s, 3H), 3.88(s, 3H), 4.36(q, 2H, J = 7.2 Hz), 6.94 (m, 2H), 7.24-7.41(m, 6H), 7.55(s, IH); MS 354 (M⁺) .

EXAMPLE 1: Preparation of 2-Phenyl-4-methyl-IH- imidazol-5-ylcarbonyl) guanidine

A solution of 2 M guanidine in methanol (4.2 ml, 8.4 mmol) was evaporated in a vacuum and the residue was added to a solution of the compound obtained in Preparation Example 3-1 (419 mg, 1.39 mmol) in DMF (5 ml), followed by stirring at 80⁰C for 16 hrs. After the reaction was terminated with water, the reaction mixture was alkalinized with 6 N NaOH and extracted twice with ethyl acetate . The organic layer was washed with brine, dried over MgSO₄, filtered and concentrated in a vacuum. The concentrate was dissolved in methanol and mixed with 1 N HCl (5 eq.) before heating under reflux with stirring for 5 hrs. Concentration in a vacuum, alkalinization with 6N NaOH, and two rounds of extraction with ethyl acetate were performed in the order after which the organic layer thus obtained was washed with brine. This extract was dried over MgSO₄, filtered and concentrated in a vacuum. The concentrate was purified through silica gel column chromatography (methanol :dichloro methane=2:l) into the object compound as a white solid (47 mg, 14%) .

¹H-NMROOO MHz, CD₃OD) σ 2.47 (s, 3H), 7.32 (in, 3H), 7.81(m, 2H); MS 243 (M⁺) .

EXAMPLE 2 : Preparation of (2- (2-methylphenyl) -4 - me thyl - IH- imidazol - 5 -ylcarbonyl ) guanidine bismethanesulfonate

A solution of 2 M guanidine in methanol (2.3 ml, 4.36 mmol) was evaporated in a vacuum and the residue was added to a solution of the compound obtained in Preparation Example 3-2 (230 mg, 0.73 mmol) in DMF (6 ml), followed by stirring at 80⁰C for 16 hrs. After the reaction was terminated with water, the reaction mixture was extracted twice with ethyl acetate. The organic layer was washed with brine, dried over MgSO₄, filtered and concentrated in a vacuum. The concentrate was dissolved- in acetone and mixed with methane sulfonic acid before stirring at room temperature for 1 hr. After the reaction was terminated with water, the precipitate thus • formed was filtered and washed many times with water and diethyl ether to afford the object object compound as a white solid (150 mg, 0.34 mmol, 70%) . 1H-NMROOO MHz, CD₃OD) σ 2.48 (s, 3H), 2.59(s, 3HO,

7.25-7.33(m, 3H), 7.48(d, IH, J = 6.7 Hz); MS 258 (M⁺) .

EXAMPLE 3: Preparation of (2- (3-methylphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine methanesulfonate

The object compound was prepared as a. white solid (105 mg, 61%) in the same procedure as in- Example 2 with the exception that the compound obtained in Preparation Example 3-3 (230 mg, 0.73 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.4β(s, 3H), 2.67(s, 3H), 2.73(s, 3H), 7.36(d, IH, J = 7.5 Hz), 7.42(dd, IH, J = 7.5, 7.7 Hz), 7.78 (d, IH, J= 1.1 Hz), 7.86 (s, IH);

MS 258 (M⁺) . EXAMPLE 4: Preparation of (2- (4-methylphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (190 mg, 67%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-4 (200 mg, 0.63 mmol) was used.

¹H-NMR(SOO MHz, CD₃OD) σ 2.41(S, 3H), 2.64(s, 3H), 2.71(s, 6H), 7.35 (d, 2H, J = 8.1 Hz), 7.86 (d, 2H, J = 8.1 Hz);

MS 258 (M⁺) .

EXAMPLE 5 : Preparation of (2- (2 , 3-dimethylphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (365 mg, 61%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-5 (430 mg, 1.30 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.42 (s, 3H), 2.43 (s, 3H), 2.71(s, 3H), 2.75(s, 6H), 7.29(dd, IH, J = 7.6, 7.7 Hz), 7.41 (m, IH); MS 271 (M⁺) . EXAMPLE 6: Preparation of (2- (2, 5-dimethylphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (300 mg, 54%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-6 (400 mg, 1.21 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.37 (s, 3H), 2.47 (s, 3H), 2.65(s, 3H), 2.70(s, 6H), 7.25(s, IH), 7.38(s, 2H), 7.78 (d, IH, J= 7.7 Hz) , 7.86 (S, IH) ; MS 271 (M⁺) .

EXAMPLE 7 : Preparation of (2- (3 , 5-dimethylphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine methanesulfonate

The object compound was prepared as a white solid (77 mg, 35%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-7 (200 mg, 0.61 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.37 (s, 6H), 2.61(s, 3H), 2.69 (s, 3H), 7.08 (s, IH), 7.59(s, 2H);

MS 271 (M⁺) . EXAMPLE 8: Preparation of (2- (2-methoxyphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (180 mg, 71%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-8 (180 mg, 0.54 mmol) was used.

¹H-NMROOO MHZ, CD₃OD) σ 2.71(s, 3H), 2.73(s, 6H), 4.06(s, 3H), 7.18(dd, IH, J = 7.5, 7.7 Hz), 7.28(d, IH, J = 8.4 Hz), 7.60 (m, IH), 8.07 (dd, IH, J= 1.7, 7.7 Hz); MS 273 (M⁺) .

EXAMPLE 9: Preparation of (2- (3-methoxyphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (108 mg, 41%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-9 (190 mg, 0.57 mmol) was used.

¹H-NMR(SOO MHz, CD₃OD) σ 2.67 (s, 3H), 2.73 (s, 6H), 3.91(s, 3H), 7.12 (m, IH), 7.47(dd, IH, J = 8.2, 8.2 Hz), 7.58 (m, 2H); MS 273 (M⁺) . EXAMPLE 10: Preparation of (2- (4-methoxyphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (230 mg, 69%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-10 (240 mg, 0.72 mmol) was used. xH-NMR(300 MHz, CHD₃OD) σ 2.68 (s, 3H), 2.74 (s, 6H), 3.91(s, 3H), 7.16 (dd, 2H, J = 2.1, 6.9 Hz), 7.98 (d, 2H, J = 2.1, 6.9 Hz) ;

MS 273 (M⁺) .

EXAMPLE 11: Preparation of (2- (2, 3-dimethoxyphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (400 mg, 68%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-11 (430 mg, 1.19 mmol) was used..

¹H-NMROOO MHz, CD₃OD) σ 2.70 (s, 3H), 2.73 (s, 6H), 3.92 (s, 3H), 3.95 (s, 3H), 7.27 (m, 2H), 7.62 (m, IH); MS 303 (M⁺) . EXAMPLE 12: Preparation of (2- (2, 5-dimethoxyphenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidiμe bismethanesulfonate

The object compound was prepared as a white solid (200 mg, 97%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-12 (150 mg, 0.42 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.70 (s, 3H), 2.73 (s, 6H), 3.87(s, 3H), 4.01(s, 3H), 7.18 (m, 2H)/ 7.65 (d, IH, J = 2.7 Hz) ;

MS 303 (M⁺) .

EXAMPLE 13: Preparation of (2- (2-fluorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (220 mg, 56%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-13 (280 mg, 0.87 mmol) was used. 1H-NMRUOO MHz, CD₃OD) σ 2.67 (s, 3H), 2.72 (s, 6H),

7.35 (m, IH), 8.13 (m, IH); MS 261 (M⁺) .

EXAMPLE 14: Preparation of (2- (3-fluorophenyl) -4- methyl-Iff-imidazol-5-ylcarbonyl) guanidine methanesulfonate The object compound was prepared as a white solid (170 mg, 69%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-14 (220 mg, 0.69 mmol) was used. 1H-NMROOO MHz, CD₃OD) σ 2.66(s, 3H), 2.73(s, 3H), 7.20 (m, IH), 7.53 (m, IH), 7.74-7.82 (m, 2H);

MS 261 (M⁺) .

EXAMPLE 15: Preparation of (2- (4-fluorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (150 mg, 60%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-15 (180 mg, 0.56 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.66(s, 3H), 2.73 (s, 6H), 7.29 (m, 2H) , 8.04 (m, 2H) ; MS 261 (M⁺) .

EXAMPLE 16: Preparation of (2- (2, 3-difluorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (110 mg, 66%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example

3-16 (120 mg, 0.36 mmol) was used. ¹H-NMROOO MHz, CD₃OD) σ 2.69(s, 3H), 2.73 (s, 6H), 7.30-7.42 (m, 2H), 7.91(m, IH); MS 279 (M⁺) .

EXAMPLE 17: Preparation of (2- (2, 5-difluorophenyl) -A- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared, as a white solid (75 mg, 54%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-17 (100 mg, 0.30 mmol) was used.

¹H-NMR(SOO MHz, CD₃OD) σ 2.67 (s, 3H), 2.73(s, 6H), 7.23-7.36 (m, 2H), 7.89-7.95 (m, IH);

MS 279 (M⁺) .

EXAMPLE 18: Preparation of (2- (3, 5-difluorophenyl) -4~ methyl-IH-imidazol-5-ylcarbonyl) guanidine methanesulfonate

The object compound was prepared as a white solid (170 mg, 51%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-18 (300 mg, 0.89 mmol) was used.

¹H-NMR(SOO MHz, CD₃OD) σ 2.66(s, 3H), 2.73 (s, 3H), 7.02-7.10 (m, 2H), 7.62 (m, IH);

MS 279 (M⁺) . EXAMPLE 19: Preparation of (2- (2-chlorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (300 mg, 62%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-19 (350 mg, 1.04 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.68 (s, 3H), 2.72 (s, 6H), 7.53 (m, 2H), 7.61(dd, IH, J= 1.4, 7.7 Hz), 7.85 (dd, IH, J= 1.7, 7.3 Hz) ;

MS 277 (M⁺) .

EXAMPLE 20: (2- (3-chlorophenyl) -4-methyl-IE-imidazol- 5-ylcarbonyl) guanidine The object compound was prepared as a white solid (120 mg, 73%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-20 (200 mg, 0.59 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.58(s, 3H), 7.73-7.46(m, 2H), 7.87 (m, IH), 7.99 (s, IH); MS 277 (M⁺) .

EXAMPLE 21: Preparation of (2- (4-chlorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate The object compound was prepared as a white solid (210 mg, 75%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-21 (200 mg, 0.59 mmol) was used. 1H-NMROOO MHz, CD₃OD) σ 2.50 (s, 3H), 2.57 (s, 6H),

7.39 (d, 2H, J = 8.5 Hz) , 7.82 (d, IH, J= 8.5 Hz); MS 277 (M⁺) .

EXAMPLE 22: Preparation of (2- (2, 3-dichlorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (190 mg, 64%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-22 (220 mg, 0.59 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.60 (s, 3H), 2.65(s, 6H), 7.38 (dd, IH, J = 7.7, 7.9 Hz), 7.62-7.70 (m, 2H);

MS 311 (M⁺) .

EXAMPLE 23: Preparation of (2- (2, 5-dichlorophenyl) -A- methyl-IH-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (280 mg, 76%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example

3-23 (271 mg, 0.73 mmol) was used. ¹H-NMROOO MHz, OD₃OD) σ 2.66(s, 3H) , 2.72 (s, 6H), 7.49(dd, IH, J = 2.5, 8.6 Hz) , 7.57(d, IH, J = 8.6 Hz) , 7.93 (d, IH, J = 2.5 Hz) ;

MS 311 (M⁺) .

EXAMPLE 24: Preparation of (2- (3, 5-dichlorophenyl) -4- methyl-IH-imidazol-5-ylcarbonyl) guanidine

The object compound was prepared as a white solid (262 mg, 64%) in the same procedure as in Example 1 with the exception that the compound obtained in Preparation Example 3-24 (485 mg, 1.31 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.40(s, 3H), 7.25(d, IH, J = 1.5 Hz) , 7.76 (m, 2H) ;

MS 311 (M⁺) .

EXAMPLE 25: Preparation of (2- (2-methoxy-5- chlorophenyl) -4-methyl-IE-imidazol-5-ylcarbonyl) guanidine bismethanesulfonate

The object compound was prepared as a white solid (280 mg, 69%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-25 (300 mg, 0.82 mmol) was used.

¹H-NMR(SOO MHz, CD₃OD) σ 2.68 (s, 3H), 2.73 (s, 6H), 4.04(s, 3H), 7.22 (d, IH, J = 8.8 Hz), 7.46(dd IH, J = 2.6, 8.8 Hz) , 8.20 (d, IH, J= 2.6 Hz);

MS 308 (M+l)⁺. EXAMPLE 26: Preparation of (2- (2-methoxy-5- fluorophenyl) -4-methyl-IH-iraidazol-5-ylcarbonyl) guanidine bismethanesulfonate The object compound was prepared as a white solid (130 mg, 50%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 3-26 (190 mg, 0.54 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.68 (s, 3H), 2.73 (s, 6H), 4.03 (s, 3H), 7.23 (m, 2H), 7.95(dd, IH, J= 2.3, 9.2 Hz);

MS 291 (M⁺) .

EXAMPLE 27: Preparation of (Λ7-methyl-2-phenyl-4- methyl-IH-imidazol-5-ylcarbonyl) guanidine The object compound was prepared as a white solid (34 mg, 16%) in the same procedure as in Example 1 with the exception that the compound obtained in Preparation Example 5-1 (195 mg, 0.80 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.52 (s, 3H), 3.86(s, 3H), 7.50-7.54 (m, 3H), 7.5-7.63 (m, 2H); MS 258 (M⁺) .

EXAMPLE 28: Preparation of (Λ7-methyl-2- (3- methylphenyl) -4-methyl-IH-imidazol-5-ylcarbonyl) guanidine The object compound was prepared as a white solid (8.4 mg, 8%) in the same procedure as in Example 1 with the exception that the compound obtained in Preparation Example 5-2 (100 rag, 0.39 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.44 (s, 3H), 2.52 (s, 3H), 3.90(s, 3H), 7.34-7.42(m, 4H); MS 271 (M⁺) .

EXAMPLE 29: Preparation of (IV-methyl-2- (2- chlorophenyl) -4-methyl-liϊ-imidazol-5-ylcarbonyl) guanidine

The object compound was prepared as a white solid (115 mg, 66%) in the same procedure as in Example 1 with the exception that the compound obtained in Preparation Example 5-3 (166 mg, 0.60 mmol).

¹H-NMROOO MHz, CD₃OD) σ 2.53 (g, 3H), 3.69(s, 3H), 7.47-7.67 (m, 4H) ; MS 291 (M⁺) .

EXAMPLE 30: Preparation .of (N-methyl-2- (3- chlorophenyl) -4-methyl-IH-imidazol-5-ylcarbonyl) guanidine

The object compound was prepared as a white solid (184 mg, 80%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 5-4 (220 mg, 0.80 mmol).

¹H-NMROOO MHz, CD₃OD) σ 2.^'53(s, 3H), 3.87 (s, 3H), 7.51-7.55 (m, 3H), 7.65 (s, IH); MS 291 (M⁺) . EXAMPLE 31 : Preparation of (N-benzyl-2- (3- methylphenyl) -4-methyl-IH-imidazol-5-ylcarbonyl) guanidine

The object compound was prepared as a white solid (98 mg, 38%) in the same procedure as in Example 2 with the exception that the compound obtained in Preparation Example 7-1 (250 mg, 0.75 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.38 (s, 3H), 2.56(s, 3H), 5.73(s, 2H), 6.89-6.94(m, 3H), 7.21-7.37 (m, 6H);

MS 348 (M⁺) .

EXAMPLE 32 : Preparation of (N-benzyl-2- (3- chlorophenyl) -4-methyl-IH-imidazol-5-ylcarbonyl) guanidine

The object compound was prepared as a white solid (99 mg, 31%) in the same procedure as in Example 1 with the exception that the compound obtained in Preparation Example 7-2 (300 mg, 0.85 mmol) was used.

¹H-NMROOO MHz, CD₃OD) σ 2.4β(s, 3H), 5.65 (s, 2H), 6.81(m, 2H), 7.14 (m, 3H), 7.32-7.40 (m, 4H);

MS 370 (M⁺) .

The structures and compounds of the present invention prepared in the examples are represented, along with the substituents thereof, in Table 1 below.

Table 1

Compounds of Chemical Formula 1 according to the present invention were assayed for various medicinal and pharmaceutical activities through the following tests .

EXPERIMENTAL EXAMPLE 1: Inhibitory Activity against

NHE-I

The novel 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention were examined for NHE-I inhibition in cells through the following experiment .

<!-!> Preparation of PS120/NHE-1 cells Human NHE-I was expressed in CCL39-derived PS120 cells. These human NHE-I expressed cells were cultured in DMEM (Dulbecco's modified Eagle's medium) supplemented with 10% fetal bovine serum, 1% penicillin/streptomycin (10Ox solution) , 1% L-glutamine (200 mM aqueous solution) . The PS120/NHE-1 cells grown in 100 mm dishes were treated with trypsin at 80-90% confluency, followed by washing once with PBS (phosphate buffer saline) , and then once with an Na-free buffer (138.2 mM choline chloride, 4.9 mM KCl, 1.5 mM CaCl₂ -2H₂O, 1.2 mM MgSO₄ -7H₂O, 1.2 mM KH₂PO₄, 15 mM D-glucose, 20 mM HEPES, at pH 7.4). After centrifugation, the pellet was suspended in an Na-free buffer containing 20 mM NH₄Cl and 10 μM BCECF-AM (2' , 7' -bis (2-carboxyethyl) -5, 6-carboxy- fluorescein acetoxymethyl ester) and incubated at 37°C for 30 min in a CO₂ incubator. After being harvested by centrifugation, the PS120/NHE-1 cells were washed once with an Na-free buffer to remove both NH₄Cl and extracellular BCECF-AM, suspended at a density of 2.5xlO⁴ cells/10 μl and stored at 4°C in a dark room until reuse.

<l-2> Evaluation of NHE-I inhibition

In each well of 96-well microplates, 180 μl of HBS (137 mM NaCl, 4.9 mM KCl, 1.5 mM CaCl₂-2H₂O, 1.2 mM MgSO₄-7H₂O, 1.2 mM KH₂PO₄, 15 mM D-glucose, 20 mM HEPES, at pH 7.4), together with 10 μl of DMSO or 10 μl of a solution of the compound (0.03 ~ 10 μM) of the present invention in DMSO, was plated and well mixed, after which 10 μl aliquots of the intracellular acidosis-induced PS120/NHE-1 cells were added thereto. 4 min after the cell addition, fluorescence (excitation: 485/444 nm, emission: 535 nm) was measured in the XEMINI-XS Microplate Spectrofluorometer (Molecular Devices) . The fluorescence measured was converted into pH values using a high-K⁺/nigericin technique. The cells in which intracellular acidosis was induced with NH₄Cl prepulses recovered normal pH values as the NHE-I operated. The inhibitory activity of the compound against NHE-I was evaluated as concentrations at which the recovery from the intracellular acidosis to a normal state was 50% inhibited (IC₅₀ values) , with cariporide (cardioprotector) used as a control. The results are given in Table 2, below.

As seen in Table 2, the control cariporide showed a high inhibitory effect on NHE-I, with an IC₅₀ value of 1.0 μM. Compounds of Examples 2, 6-9, 12, 14, 17-19, and 22-26 according to the present invention were also inhibitory of NHE-I, with IC₅₀ values as low as or less than 5.0 μM. Of them, compounds of Examples 22, 23, 25 and 26 had IC₅₀ values less than 0.8 μM, showing more potent inhibitory activity against NHE-I than that of cariporide. Particularly, the compound of Example 23 has an IC₅₀ of 0.10 μM, which is 10- fold more potent than cariporide.

Hence, the novel 4-methylimidazol-5- ylcarbonylguanidine derivatives of • the present invention can be used as cardioprotectors against ischemia/reperfusion thanks to their potent inhibitory effect on NHE-I.

EXPERIMENTAL EXAMPLE 2: Cardioprotective Effect in Isolated Ischemic Rat Heart

For use as an ischemic heart model in the experiment for examining whether the novel 4-methylimidazol-5- ylcarbonylguanidine derivatives of the present invention were cardioprotective, the heart was excised from rats as follows .

Male rats (300-450 g, the Korea Research Institute of Chemical Technology, Experimental Animal Lab) were anesthetized by intraperitoneal injection with sodium pentobarbital at a dose of 100 mg/kg and were intravenously administered with heparine at a dose of 1000 U/kg, followed by the excision of the heart. In detail, a tracheotomy was performed and a tracheal cannula (PE 240) was inserted into the trachea for subsequent artificial ventilation with room air using a rodent ventilator. Following thoracotomy, the heart was rapidly excised, mounted on a Langendorff apparatus and perfused via retrograde cannulation of the aorta at a constant perfusion pressure of 85 mmHg using a

37°C physiological buffer saturated _t with 95% O₂/5% CO₂

(modified Krebs-Henseleit bicarbonate buffer; 116 mM/L NaCl,

4.7 mM/L KCl, 1.1 mM/L MgSO4, 1.17 mM/L KH₂PO₄, 24.9 mM/L NaHCO₃, 2.52 mM/L CaCl₂, 8.32 mM/L Glucose, 2.0 mM/L pyruvate) . A catheter tip manometer connected to a latex balloon filled with a mixture of ethanol and distilled water

(1:1 v/v) was inserted via an incision in the left atrium into the left ventricle, and the intraventricular pressure thereof transmitted to the latex balloon was measured isovolumetrically with a pressure transducer and recorded on a recording system (Linearcorder mark 8 WR 3500) with the aid of an amplifier (Plugsys bridge amplifier) . After stabilizing the heart for 15 min, the balloon volume was adjusted to create a left ventricular end-diastolic pressure (LVEDP) of 5 mmHg during the initial baseline period. The volume of the balloon was not modified until the end of the experiment .

Baseline heart contraction function, spontaneous heart rate (HR) and coronary flow (CF) were determined from the left ventricular contraction interval. The left ventricular developed pressure (LVDP) , which is regarded as an index of contractile function of the isolated heart, was calculated by subtracting left ventricular end-diastolic pressure (LVEDP) from left ventricular peak systolic pressure (LVSP) . In contrast to the heart in the body, the Langendorff heart cannot be measured for cardiac output and thus, RPP (rate- pressure product) , which is an important indirect indicator for cardiac performance, was calculated by multiplying heart rate (HR) by LVDP. Throughout the experiment, the temperature of the heart was maintained constant by immmersing the heart in a 37⁰C physiological solution to which 95% O₂/5% CO₂ was continuously supplied. The heart thus stabilized was perfursed for 10 min with a solution of the compounds of the invention or control drugs in DMSO

(dimethylsulfoxide) diluted with HBS (final DMSO cone.

0.04%), or with the solvent only (a negative control; 0.04%

DMSO) and then measured again for contractile function, heart rate (HR) and coronary flow (CF) . The supply of perfusates was completely stopped for 30 min in order to induce global ischemia in the heart, followed by reperfusion for 30 min. The indices (LVDP, HR, LVEDP, and CF) were measured again. After the reperfusion, the total level of lactate dehydrogenase (LDH) in the reperfusates was measured using a kit and taken as an index of ischemic myocardial injury. A negative control group was treated with the solvent only while cariporide was used as a positive control . The results are summarized in Table 3, below.

TABLE 3

In the isolated ischemia/reperfusion rat heart experiment, as shown in Table 3, the negative control was significantly lowered in contractile function as its RPP (LVDP x HR) , an index of the contractile function of the heart, was reduced to as low as 15.5% relative to that before the ischemia induction. The reperfusional LVEDP, which indicates the myocardiac contracture upon ischemia/reperfusion, serving as an index of cardioprotective activity, significantly increased from 5 mmHg to 55.3 mmHg in the negative control.

The group treated with 10 μM of cariporide was considerably improved with respect to myocardiac contractile function (LVDP x HR) after the reperfusion, amounting to as large as 47.6% of that before the ischemia induction, as compared with the negative control . The LVEDP of the cariporide-treated group was 22.4 mmHg, which was significantly low relative to that of the negative control, implying that it had a protective effect on the ischemic heart. When the rat hearts were treated with 10 μM of each of the compounds of Examples 6 and 26, .they were observed to have myocardiac contractile functions of 33.5% and 45.5% of that before the ischemia induction/ and LVEDP of 31.7 mmHg and 39.5 mmHg, respectively, significantly increasing in cardioprotective activity as compared with the negative control (15.5%, 55.3 mmHg) . The compounds of Examples 23 and 25, which have 10-fold and 4-fold more potent inhibitory activity against NHE-I than that of cariporide (Table 2) , were found to have higher cardioprotective effects after ischemic/reperfusional heart injury as they recovered myocardiac contractile functions to 59,2% and 60.2% of that before for ischemia induction and decreased LVEDP to 25.0 mmHg and 27.7 mmHg, respectively. The compound of Example 19, which is slightly lower in NHE-I inhibitory activity than cariporide (0.7-fold), ensured a myocardiac contractile function of 68.9% of that before the ischemia induction, which demonstrates superior myocardiac contractile function than that of cariporide. Therefore, the compounds of the present invention show excellent protective effects on ischemic hearts by effectively promoting the functional recovery of ischemia/reperfusion-induced heart injury, so that they can be effectively used for the prophylaxis and treatment of ischemic heart diseases. EXPERIMENTAL EXAMPLE 3 : Cardioprotective Effect on in vivo Ischemic Rat Heart Model

The cardioprotective activity of the novel 4- methylimidazol-5-ylcarbonylguanidine derivatives according to the present invention in in vivo ischemic hearts was judged with regard to their antiischemic effects (myocardiac infarction reduction) on rats as follows.

Each male rat (300-450 g, the Korea Research Institute of Chemical Technology, Experimental Animal Lab) was anesthetized by intraperitoneal injection with sodium pentobarbital at a dose of 75 mg/kg. Tracheotomy was performed and a tube was inserted into the trachea for subsequent artificial ventilation with a stroke volume of 10 ml/kg and a respiratory rate of 60 breaths/min. The femoral vein and the femoral artery were cannulated for the administration of the compounds and for the measurement of blood pressures, respectively. Meanwhile, the body temperature of the rats, an important factor to influence experimental results in the ischemic myocardiac injury model, was maintained constant at 37⁰C using a homeothermic blanket control unit, with a body temperature-monitoring probe inserted into the rectum. Subsequently, rats were continuously measured for mean arterial blood pressure and heart rate HR throughout the experimental time period using a Statham P23XL pressure transducer (Grass Ins . , MA, USA) and an ECG/RATE Coupler (Hugo Sachs Electronic, Germany) , respectively, with all continuous changes thereof recorded by Graphtec Linearcorder WR 3310 (Hugo Sachs Electronic) .

The left coronary artery was occluded according to Selye H.'s method. In detail, after the chest of each rat was partially opened by left thoracotomy, the middle finger of the left hand was pressed against the right side of the chest of the rat to thrust out the heart which was then slightly fixed with the forefinger and the thumb of the same hand. Then, immediately after the left anterior descending coronary artery (LAD) was sutured with a 5-0 silk ligature, the heart was repositioned back in the thoracic cavity with both ends of the suture positioned outside . The ends of the suture were threaded through a PE tube (PElOO, 2.5 cm) and allowed to stand for 20 min for stabilization. Through the cannula inserted into the femoral, vein, a vehicle or the compounds of the invention were administered and 30 min was needed for sufficient effects of the administered compounds . Cariporide was used as a control . The ends of the suture threaded through the PE tube were pulled taut with a hemostatic pincette to vertically press the PE tube against the coronary artery. After occlusion for 45 min, the hemostatic pincette was removed and reperfusion was conducted for 90 min. The coronary artery was reoccluded in the same manner as described above, followed by the intravenous injection of 2 ml of 1% Evans blue. The intravenous injection of an excess of pentobarbital killed the rats, from which the hearts were then excised. The left ventricle was removed alone from the isolated heart and transected from the cardiac apex into 5 or 6 slices. Each slice was weighed. The image of each of the heart slices was captured using a Hi-scope, a compact vision system, and analyzed for blue- stained normal areas and non-stained areas with an image analyzing program (Image Pro Plus) . In each slice, the area at risk (AAR) was calculated by multiplying the ratio of the non-stained area to the total area of the slice with the weight of the slice. Sum of the individual area at risk (AAR) for each slice was divided by the total weight of the left ventricle to obtain AAR (%) according to the following mathematical formula 1.

Mathematical Formula 1

V AAR for each Slice

AAR(%) = —±± x 100

Total Left Ventricle Weight

Separately, the heat slices were incubated in 1% 2, 3, 5-triphenyltetrazolium chloride (TTC) phosphate buffer (pH 7.4), 37°C, for 15 min and fixed in 10% formalin for 20-24 hours. In the normal area of the tissue, 2, 3, 5- triphenyltetrazolium chloride was reduced by the myocardial dehydrogenase in the presence of the cofactor NADH to form formazan dye, which appeared as a brick-red color, . In contrast, infarction areas of the tissue did not appear dark red because 2,3, 5-triphenyltetrazolium chloride was not reduced due to their lack of the dehydrogenase and the cofactor.

Taking advantage of 2, 3, 5-tr.iphenyltetrazolium chloride, each slice was analyzed to determine normal area and infarct size (IS) in the same manner as in AAR. The sum of the individual infarct sizes for each slice was divided by the total weight of AAR or left ventricle to calculate IS (%) according to the following Mathematical Formula 2. In this experimental model, lower IS (%) reflected smaller infarct sizes, implying more potent anti-ischemic effects of the compounds . The results are shown in Table 4.

Mathematical Formula 2

^ Infarct Size for each Slice

IS(%) = x 100

Total Weight of AAR or Left Ventricle

TABLE 4

Cariporide 0 .1 mg/kg 40.5

1: IS/AAR(infarct size/area risk)

As is apparent from the data of Table 4 , the novel 4- methylimidazol-5-ylcarbonylguanidine derivatives of the present invention were found to significantly reduce myocardiac infarction rates with regard to area at risk in the in vivo ischemic myocardiac injury model. In more detail, the vehicle-administered group had a myocardiac infarction rate relative to area at risk (IS/AAR, %) of as high as 58.6%, suffering from very serious myocardiac injury. The positive control cariporide showed significant anti- ischemic activity, as it allowed myocardiac infarction rates to be 40.5% at an injection dose of 0.1 mg/kg. Compounds of Examples 20 and 23 showed myocardiac infarction rates of 40.0% and 40.3% respectively, which were similar to that of cariporide. When the compound of Example 25 was injected at a dose of 0.1 mg/kg, the myocardiac infarction rate was observed to be 34.2%, demonstrating significantly more potent cardioprotective activity than that of cariporide

(40.5%). Particularly, the compound of Example 25 was evaluated to have four-fold more potent inhibitory activity against NHE-I, highly promote the functional recovery of the isolated ischemic/reperfusional rat Langendorff heart model, significantly reduce myocardiac infarction rates in rat in vivo ischemic heart model than cariporide. Therefore, the novel ^■ 4-methylimidazol-5- ylcarbonylguanidine derivatives of the present invention, as demonstrated by the low myocardiac infarction rates in in vivo ischemic heart models, effectively protect the heart from ischemia so that they can be useful for the prophylaxis and treatment of ischemic heart disease such as myocardiac infarction, arrhythmia, angina pectoris, and the like, and are effective as cardioprotective agents for cardiac surgery, such as coronary artery bypass and percutaneous transluminal coronary angioplasty immediately.

EXPERIMENTAL EXAMPLE 4 : Assay for Acute Oral Toxicity in Rat

The novel 4-methylimidazol-5-ylcarbonylguanidine derivatives of the present invention were assayed for acute oral toxicity as follows .

Specific pathogen free (SPF) SD rats 6 weeks old were used for this assay. The compound of Example 25 was suspended in a 0.5% methylcellulose solution, and the suspension was orally administered at a dose of 10 mg/kg/15 ml to respective groups of two rats .

After the oral administration, the rats were observed for death, clinical symptoms, change in body weight, and the like, and subjected to hematological and serobiochemical tests . Autopsy was performed to examine the abnormality of thoracic and abdominal organs with the naked eyes .

Neither particular clinical symptoms nor perished animals were observed. In addition, no acute toxicity was observed in body weight change, haematological test, serobiochemical test, and autopsy examination. These results demonstrate that the compounds tested do not induce toxicity to the dose of 10 mg/kg in rats, and are proven safe with an LD₅₀ of 100 mg/kg or more upon oral administration.

Furthermore, the compounds according to the present invention may be formulated in various forms according to the intended purpose. Formulations containing the compounds of the present invention as effective ingredients are illustrated in the following examples, but are not construed to limit the scope of the invention.

FORMULATION EXAMPLE 1: Tablet (Direct Compression)

Cpd. Of the present invention 5.0 mg

Lactose 14.1 mg

Crospovidone USNF 0.8 mg

Mg Stearate 0.1 mg After being sieved, the compound of the present invention was mixed with lactose, crospovidone USUF and magnesium stearate and compressed into tablet form.

FORMUALATION EXAMPLE 2: Tablet (Wetting Formula)

Cpd. Of the present invention 5.0 mg, Lactose 16.0 mg

Glucose 4.0 mg Polysolvate 80 0.3 mg

Colloidal silicon dioxide 2.7 mg

Mg Stearate 2.0 mg

Distilled water suitable amount

After being sieved, the compound of the present invention was mixed with lactose and starch. To a solution of polysolvate 80 in distilled water was added the mixture. After section to a fine size, the fine powder was dried, sieved, and mixed with colloidal silicon dioxide and magnesium stearate. Compression of the mixture gave a tablet.

FORMULATION EXAMPLE 3: Powder

Cpd. Of the present invention 5.0 mg, Lactose 14.8 mg

Polyvinyl pyrrolidone 10.0 mg Mg Stearate 0.2 mg

The compound of the present invention was sieved and mixed with lactose, polyvinyl pyrrolidone, and magnesium stearate. The mixture was filled in an air-tight sac.

FORMULATION EXAMPLE 4: Capsule

Cpd. Of the present invention 5.0 mg, Lactose 14.8 mg Polyvinyl pyrrolidone 10.0 mg

Mg Stearate 0.2 mg

The compound of the present invention was sieved and mixed with lactose, polyvinyl pyrrolidone, and magnesium stearate. The mixture was filled in a hard gelatine capsule, using a suitable apparatus.

FORMULATION EXAMPLE 4: Injection

Cpd. Of the present invention 100 mg, Mannitol 180 mg

Na₂HPO₄ ^• 12H₂O 26 mg

Distilled water 2974 mg

The compound of the present ,^φ invention was dissolved, along with mannitole and Na₂HPO₄. 12H₂O, in distilled water and the pH of the solution was adjusted into 7.4 before sterilizing. An injection was prepared according to a typical procedure .

Claims

[CLAIMS]

[Claim l]

A 4-methylimidazol-5-ylcarbonylguanidine derivative represented by the following Chemical Formula 1 or a pharmaceutically acceptable salt thereof . [Chemical Formula 1]

(wherein, R¹ and R² are each independently hydrogen, a halogen atom, trihalomethyl, mesyl, nitro, amino, straight or branched Ci-C₅ alkyl, or OR³ wherein R³ is hydrogen, trihalomethyl, straight or branched Ci-C₅ alkyl, or phenyl, and X is hydrogen, straight or branched Ci-C₅ alkyl, or benzyl . )

[Claim 2]

The 4-methylimidazol-5-ylcarbonylguanidine derivative or the pharmaceutically acceptable salt according to claim 1, wherein,

R¹ and R² are each independently hydrogen, F, Cl, Br, I, -CF₃, -CCl₃, mesyl, nitro, amino, s.traight or branched Ci-C₃ alkyl, or OR³ wherein R³ is hydrogen, -CF₃, -CCl₃, straight or branched C₁-C₃ alkyl, or phenyl, and

X is hydrogen, straight or branched C₁-C₃ alkyl, or benzyl .

[Claim 3]

R¹ and R² are each independently hydrogen, F, Cl, methyl, or OR³ wherein R³ is methyl, and X is hydrogen, methyl or benzyl.

[Claim 4]

The 4-methylimidazol-5-ylcarbonylguanidine derivative or the pharmaceutically acceptable salt according to claim 1, being selected from a group consisting of :

1) (2-phenyl-4-methyl-lff-imidazol-5- ylcarbonyl) guanidine;

2) (2- (2-methylphenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 3) (2- (3-methylphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine methanesulfonate;

4) (2- (4-methylphenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 5) (2- (2, 3-dimethylphenyl) -4-methyl-lH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

6) (2- (2, 5-dimethylphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 7) (2- (3,5-dimethylphenyl) -4-methyl-lH-imidazol-5- ylcarbonyl) guanidine methanesulfonate;

8) (2- (2-methoxyphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

9) (2- (3-methoxyphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

10) (2- (4-methoxyphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

11) (2- (2,3-dimethoxyphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 12) (2- (2,5-dimethoxyphenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

13) (2- (2-fluorophenyl) -4-methyl-lH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

14) (2- (3-fluorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine methanesulfonate;

15) (2- (4-fluorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

16) (2- (2, 3-difluorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 17) (2- (2, 5-difluorophenyl) -4-methyl-IH-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 18) (2- (3, 5-difluorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine methanesulfonate,-

19) (2- (2-chlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate; 20) (2- (3-chlorophenyl) -4-methyl-IJf-imidazol-5- ylcarbonyl) guanidine;

21) (2- (4-chlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

22) (2- (2,3-dichlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

23) (2- (2, 5-dichlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine bismethanesulfonate;

24) (2- (3, 5-dichlorophenyl) -4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine; 25) (2- (2-methoxy-5-chlorophenyl) -4-methyl-Iff- imidazol-5-ylcarbonyl) guanidine bismethanesulfonate;

26) (2- (2-methoxy-5-fluorophenyl) -4-methyl-lff- imidazol-5-ylcarbonyl) guanidine bismethanesulfonate;

27) (N-methyl-2-phenyl-4-methyl-Iff-imidazol-5- ylcarbonyl) guanidine;

28) (Af-methyl-2- (3-methylphenyl) -4-methyl-Iff-imidazol- 5-ylcarbonyl) guanidine;

29) (Λf-methyl-2- (2-chlorophenyl) -4-methyl-Iff-imidazol- 5-ylcarbonyl) guanidine; 30) (N-methyl-2- (3-chlorophenyl) -4-methyl-Iff-imidazol- 5-ylcarbonyl) guanidine; 31) (N-benzyl-2- (3 -methylphenyl) -4-methyl-IH-imidazol- 5-ylcarbonyl) guanidine; and

32) (JV-benzyl-2- (3-chlorophenyl) -4-methyl-IH-imidazol- 5-ylcarbonyl) guanidine .

[Claim 5)

A method of preparing a 4-methylimidazol-5- ylcarbonylguanidine derivative of claim 1 or a pharmaceutically acceptable salt thereof, as illustrated by the following Reaction Scheme 1, comprising reacting a carboxylic acid derivative, having a leaving group (L) , of Chemical Formula 2 with guanidine to afford the 4- methylimidazol-5-ylcarbonylguanidine derivative of Chemical Formula 1.

[Reaction Scheme 1]

2 1

(wherein, R¹, R² and X are each as defined in Chemical Formula 1 and L is a leaving group . )

[Claim 6] The method according to claim 5, wherein the leaving group (L) is selected from a group consisting of a halogen atom, hydroxy, alkoxy, mesylate and tosylate..

[Claim 7] The method according to claim 5, wherein the guanidine is used in an amount of 1 ~ 10 equivalents of the carboxylic acid derivative in the absence of a base catalyst.

[Claim 8]

The method according to claim 7, wherein the reaction solvent is an alcoholic solvent selected from a group consisting of methanol, ethanol, isopropanol and combinations thereof; an ether solvent selected from a group consisting of tetrahydrofuran, 1,4-dioxane, 1,2- dimethoxyethanol and combinations thereof; dimethylformamide; or a combination thereof.

[Claim 9]

The method according to claim 5, wherein guanidine is used in the same equivalent as that of the carboxylic acid derivative in the presence of a base catalyst .

[Claim 10]

The method according to claim 9, wherein the base catalyst is an inorganic or organic base selected from a group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, triethylamine and pyridine.

[Claim ll]

The method according to claim 9, wherein the reaction solvent is an aromatic hydrocarbon selected from a group consisting of benzene, toluene and combinations thereof; an ether solvent selected from a group consisting of tetrahydrofuran, 1,4-dioxane, and combinations thereof; a halogenohydrocarbon selected from a group consisting of dichloromethane, chloroform and combinations thereof; dimethylformamide; or a combination thereof.

[Claim 12]

The method according to claim 5 or 6, wherein the method is conducted in the presence of a condensing agent when the leaving group is hydroxyl .

[Claim 13]

The method according to claim 12, wherein the condensing agent is selected from a group consisting of N, N- carbonyldiimidazole, dicyclohexylcarbodiimide, diisopropylcarbodiimide, l-ethyl-3- (3- dimethylaminopropyl) carbodiimide, and diphenylphosphonylazide . [Claim 14]

The method according to claim 5, wherein when he carboxylic acid derivative needs to be protected by a protecting group, the method further comprises protecting the carboxylic acid derivative and deprotecting the carboxylic acid derivative before and after the reacting, respectively.

[Claim 15]

A pharmaceutical composition for prevention and treatment of an ischemic heart disease, comprising a 4- methylimidazol-5-ylcarbonylguanidine derivative represented by Chemical Formula 1 of claim 1 or a pharmaceutically acceptable salt thereof as an active ingredient.

[Claim 16] A pharmaceutical composition according to claim 15, wherein the ischemic heart disease is selected from a group consisting of myocardiac infarction, arrhythmia, angina pectoris and combinations thereof.

[Claim 17] A pharmaceutical composition for use in cardioprotection upon surgery or chemical therapy, comprising a 4-methylimidazol-5-ylcarbonylguanidine derivative represented by Chemical Formula 1 of claim 1 or a pharmaceutically acceptable salt thereof as an active ingredient .

[Claim 18] A pharmaceutical composition according to claim 17, wherein the surgery is coronary artery bypass or percutaneous transluminal coronary angioplasty and the chemical therapy is a reperfusion therapy using a thrombolytic agent.