WO2009048274A2

WO2009048274A2 - Benzofuran and benzothiophene derivatives substituted with amide, process for the preparation thereof, and pharmaceutical compositions containing the same

Info

Publication number: WO2009048274A2
Application number: PCT/KR2008/005933
Authority: WO
Inventors: Jeehee Suh; Sung-Eun Yoo; Kyu Yang Yi; Nakjeong Kim; Eunhee Kim; Yong-Sam Jung; Yun-Suk Lee; Haeyoung Suh-Kim
Original assignee: Korea Research Institute of Chemical Technology KRICT
Current assignee: Korea Research Institute of Chemical Technology KRICT
Priority date: 2007-10-12
Filing date: 2008-10-09
Publication date: 2009-04-16
Anticipated expiration: 2010-04-12
Also published as: KR100937134B1; KR20090037744A; WO2009048274A3

Abstract

The present invention relates to a novel benzofuran or benzothiophene derivative substituted with amide. The inventive benzofuran or benzothiophene derivative substituted with amide effectively inhibits ischemic cell death, and thus, can be advantageously used for preventing and treating ischemic diseases such as brain ischemia, heart ischemia, diabetic cardiovascular disease, heart failure, myocardial hypertrophy, retinal ischemia, ischemic colitis, ischemic acute renal failure, stroke, head trauma, Alzheimer's disease, Parkinson's disease, neonatal hypoxia, glaucoma, and diabetic neuropathy.

Description

BENZOFURAN AND BENZOTHIOPHENE DERIVATIVES

SUBSTITUTED WITH AMIDE, PROCESS FOR THE PREPARATION

THEREOF, AND PHARMACEUTICAL COMPOSITIONS CONTAINING

THE SAME

FIELD OF THE INVENTION

The present invention relates to a benzofuran or benzothiophene derivative substituted with amide, a method for the preparation thereof, and a pharmaceutical composition comprising the same.

BACKGROUND OF THE INVENTION

Ischemia, a symptom of reduced blood supply to organs or tissues is caused by contraction or occlusion of the blood vessel. Once ischemia occurs, subsequent reperfusion causes various sequelae due to the damaged nerve cells. Ischemia is frequently associated with coronary artery diseases, cardiovascular diseases, angina pectoris, headache or other symptoms related to such reduced blood supply, which ultimately leads to necrosis of the cells or tissues involved.

Ischemic diseases such as myocardial infarction, arehythmia or heart failure caused by the cell damage and cell dysfunction induced by ischemia-reperfusion are accompanied by high morbidity and mortality rates, and therefore, they have been the subject of extensive researches and clinic studies for the last fifty years (Wang, Q. D. et al., Cardiovasc. Res. 55:25-37, 2002). As the ischemia- reperfusion injury also affects various physiological functions involving the change of metabolism, immune response and ion homeostasis, generation of oxygen free radicals and others, it has been subjected to various studies in the field related to immune modulators, cell death suppressors, and ion channel modulators (Hearse, D. J. et al., MoI. Cell. Biochem. 186:177-184, 1998). Based on the results of such studies, there have been developed a number of therapeutics and surgical operational procedures which employ specific therapeutic compounds, but none of them have been approved for practical application. Therefore, there is a need for a new drug for preventing or treating ischemic heart diseases or for protecting heart, which can delay the progress of ischemic damage of cardiomyocytes and reduce reperfusion-induced injuries. It has also been known that when ischemia is alleviated by restoring the blood supply, the generation of reactive oxygen species (ROS) becomes accelerated, which, in turn, induces a marked decrease in the glutathione level, to cause serious diseases similar to those observed when the blood supply is interrupted or restored during a transplant surgery of an organ such as heart, liver, lung, pancreas or blood vessel. Reactive oxygen species and reactive free radicals are assumed to cause such diseases, and such species have been detected in the cytoplasm cell and organelle constructing tissues, especially in mitochondria producing ATP, the main energy source of cells. Further, it has been observed that the above-mentioned reactive species are released in mitochondria mainly through the respiratory chain, and the concentrations thereof significantly increase during ischemia-reperfusion.

Ischemia leads to cell death, especially after reperfusion, which is the main cause of various ischemic diseases involving brain ischemia, heart ischemia, diabetic cardiovascular disease, heart failure, myocardial hypertrophy, retinal ischemia, ischemic colitis, and ischemic acute renal failure.

It has been reported that in the case of brain ischemia, the depletion of the energy supply caused by reduced blood supply induces ischemic cell death, which excessively activates cell membrane receptors, leading to various biochemical alterations, e.g., the accumulation of glutamic acid on the outside and calcium on the inside of the cells, to injure the brain tissues (Liu, P. K., J. Biomed. Sci. 10:4-13, 2003; Lipton, P., Physiol. Rev. 79:1431-1568, 1999; and Renolleau, S. et al., Stroke 29:1454-1460, 1998).

In case of heart ischemia, it has been reported that myocardial infarction, heart failure, and arrhythmia are each linked to ischemic cell death caused by the activation of lipid enzymes, leading to damaged cell membranes among others (Ferrari, R. Rev. Port. Cardiol. 5:7-20, 2000; Webster, K. A. et al., J. Clin. Invest. 104:239-252, 1999; Katz, A. M. et al., J. MoI Cell. Cardiol. 2:11-20, 1985; and Vandeplassche, G. et al., Basic Res. Cardiol. 85:384-391, 1990). The retinal ischemia has been reported to be caused by cell death of retinal cells caused by glutamate salt in combination with ischemic cell death (Napper, G. A. et al., Vis. Neurosci. 16:149-158, 1999). Insufficient blood supply to the colon results in ischemic cell death, causing occlusive artery injuries and hemodynamic disorders, and ultimately ischemic colitis (Saegesser, F. et al., Pathobiol. Annu. 9:303-337, 1979).

Minocycline, a tetracycline antibiotic for inhibiting ischemic cell death, has been known to be effective in treating ischemic diseases such as cerebral infarction (Yrjanheikki, J. et al., Proc. Natl. Acad. ScL USA 96:13496-13500, 1999), myocardial infarction (Scarabelli, T. M. et al., J. Am. Coll. Cardiol. 43:865- 874, 2004), and ischemic acute renal failure (Wang, J. et al., J. Biol. Chem. 279:19948-19954, 2004), which suggests that the above-mentioned diseases are caused by ischemic cell death. It has also been elucidated that nerve cells damage or death induced by ischemia is involved in various nerve diseases such as stroke, head trauma, Alzheimer's disease, Parkinson's disease, neonatal hypoxia, glaucoma, or diabetic neuropathy (G. J. Zoppo et al., Drugs 54, 9 (1997); and I. Sziraki et al., Neurosci. 85, 1101 (1998)). The present inventors have therefore endeavored to develop a compound which has improved activity in treating ischemic diseases, and have found that a benzofuran or benzothiophene derivative substituted with amides inhibits ischemic cell death, and thus, can be used for preventing and treating ischemic diseases such as brain ischemia, heart ischemia, diabetic cardiovascular disease, heart failure, myocardial hypertrophy, retinal ischemia, ischemic colitis, ischemic acute renal failure, stroke, head trauma, Alzheimer's disease, Parkinson's disease, neonatal hypoxia, glaucoma, and diabetic neuropathy.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide a benzofuran or benzothiophene derivative inhibiting ischemic cell death, and thus being capable of preventing and treating ischemic cell death-related diseases such as brain ischemia, heart ischemia, diabetic cardiovascular disease, heart failure, myocardial hypertrophy, retinal ischemia, ischemic colitis, ischemic acute renal failure, stroke, head trauma, Alzheimer's disease, Parkinson's disease, neonatal hypoxia, glaucoma, and diabetic neuropathy; and a method for preparing said compound.

It is another object of the present invention to provide a pharmaceutical composition comprising said compound as an active ingredient.

In accordance with one aspect of the present invention, there is provided a benzofuran or benzothiophene derivative of formula (I), or a pharmaceutically acceptable salt thereof:

wherein,

R¹ is -CO₂R² or , R² being H or a straight, branched or cyclic chain C₁-C₆ alkyl;

B is H, or phenyl optinally substituted with halogen or Ci-C₃ alkyl; n is an integer ranging from 0 to 2;

Y is S; z is H or halogen;

X is O or S;

W is H or halogen; and

A and A' are each independently CH or N.

In accordance with another aspect of the present invention, there is provided a method for preparing the compound of formula (I). In accordance with further aspect of the present invention, there is provided a pharmaceutical composition for preventing or treating ischemic diseases, which comprises the compound of formula (I) or the pharmaceutically acceptable salt thereof as an active ingredient.

In accordance with still further aspect of the present invention, there is provided a pharmaceutical composition for protecting organs, which comprises the compound of formula (I) or the pharmaceutically acceptable salt thereof as an active ingredient.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects and features of the present invention will become apparent from the following description of the invention, when taken in conjunction with the accompanying drawings which respectively show:

FIG. 1: inhibitory effects of the benzofuran and benzothiophene derivatives of the present invention against hypoxemia-induced ischemic cell death, and

FIG. 2: inhibitory effects of the benzofuran and benzothiophene derivatives of the present invention against cerebral ischemia- induced cerebral infarction.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a benzofuran or benzothiophene derivative substituted with amide, a method for the preparation thereof, and a pharmaceutical composition for preventing or treating ischemic diseases, comprising the same.

Preferably, the present invention provides the compound of formula (I), wherein:

R¹ is -CO₂R² or , R² being H₅ methyl or ethyl;

B is H, or phenyl optinally substituted with halogen or C₁-C₃ alkyl; n is 0 or 1; Y is S; z is H or halogen; X is O or S;

W is H or halogen; and

A and A' are each independently CH or N.

In the present invention, representative examples of the benzofuran or benzothiophene derivative substituted with amide include:

1) 3-(2-phenylsulfanyl-acetylamino)-benzofuran-2-carboxylic acid methyl ester;

2) 3 - [2-(4-bromo-phenylsulfanyl)-acetylamino] -benzofuran-2-carboxylic acid methyl ester;

3) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-4-chloro-benzofuran-2- carboxylic acid methyl ester;

4) 3 - [3 -(4-bromo-phenylsulfanyl)-propionylamino]-benzofuran-2- carboxylic acid methyl ester; 5) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-benzoflιran-2-carboxylic acid;

6) 4-chloro-3-(3-(pyridin-2-ylsulfanyl)-propionylamino]-benzofuran-2- carboxylic acid methyl ester;

7) 3 - [2-(4-bromo-phenylsulfanyl)-acetylamino] -fϊiro[2,3 -b]pyridin-2- carboxylic acid methyl ester;

8) 3-(3-(pyridin-2-ylsulfanyl)-propionylamino]-furo[2,3-b]pyridin-2- carboxylic acid methyl ester;

9) 3-[2-(4-bromo-phenylsulfanyl)-2-phenyl-acetylamino]-benzofuran-2- carboxylic acid methyl ester; 10) 2-(4-bromo-phenylsulfanyl)-N-[2-(4,5-dihydro-oxazol-2-yl)- benzofuran-3-yl]-2-phenyl-acetamide;

11) 3-(2-phenylsulfanyl-acetylamino)-benzo[b]thiophene-2-carboxylic acid methyl ester;

12) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-benzo[b]thiophene-2- carboxylic acid methyl ester;

13) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-4-chloro- benzo[b]thiophene-2-carboxylic acid methyl ester; 14) 3-(3-phenylsulfanyl-propionylamino]-benzo[b]thiophene-2-carboxylic acid methyl ester;

15) 3-[3-(4-bromo-phenylsulfanyl)-propionylamino]-benzo[b]thiophene- 2-carboxylic acid methyl ester; 16) 4-chloro-3-(3-(pyridin-2-ylsulfanyl)-propionylamino]- benzo[b]thiophene-2-carboxylic acid methyl ester;

17) 3-[2-(4-bromo-phenylsulfanyl)-2-phenyl-acetylamino]- benzo[b]thiophene-2-carboxylic acid methyl ester;

18) 3 - [2-(4-bromo-phenylsulfanyl)-acetylamino]-thieno [2,3 -b]pyridin-2- carboxylic acid methyl ester; and

19) 3 -(3 -(pyridin-2-ylsulfanyl)-propionylamino]-thieno [2,3 -b]pyridin-2- carboxylic acid methyl ester.

Further, the respective structures of the compounds listed above are shown in Table 1 :

The benzofuran or benzothiophene derivative of the present invention may exist in the form of a pharmaceutically acceptable salt, a solvate, a hydrate or an enantiomer thereof. The pharmaceutically acceptable salt of the benzofuran or benzothiophene derivative of the present invention may be an acid addition salt formed with a pharmaceutically acceptable free acid, and the free acid may be an organic or inorganic acid. Examples of the organic acid include citric acid, maleic acid, fumaric acid, gluconic acid, methane sulfonic acid, acetic acid, glycolic acid, succinic acid, tartaric acid, 4-toluenesulfonic acid, galacturonic acid, embonic acid, glutamic acid and aspartic acid, while the inorganic acid may be hydrochloric acid, hydrobromic acid, sulfuric acid, sulfurous acid, or phosphoric acid, preferably methane sulfonic acid or hydrochloric acid.

The acid addition salt of the present invention may be prepared by a conventional method, for example, by dissolving the benzofuran or benzothiophene derivative of formula (I) in a water-miscible organic solvent such as acetone, methanol, ethanol and acetonitrile, adding thereto an excess amount of the organic acid or an aqueous solution of the inorganic acid, to induce the precipitation of the salt from the resulting mixture, removing the solvent and remaining free acid therefrom, and isolating the precipitated salts.

Also, the present invention provides a method for preparing the compound of formula (I).

The benzofuran or benzothiophene derivative of formula (I) may be prepared by reacting a benzofuran or benzothiophene derivative of formula (II) with a compound of formula (III) in the presence of a solvent and a base:

wherein, R¹, B, n, Y, z, X, W, A and A' have the same meanings as defined in formula (I); and

L is a leaving group.

In the present invention, a compound of formula (Ia), which is the compound of formula (I) wherein R¹ is ester, may be prepared by reacting a compound having a leaving group, i.e., L, of formula (Ila) with the compound of formula (III) in the presence of a solvent and a base:

wherein, B, n, Y, z, X, W, A and A' have the same meanings as defined in formula (I);

R² is H, methyl or ethyl; and

L is a leaving group, i.e., halide, mesylate or tosylate.

In this reaction, the base, which may be an organic base such as pyridine, triethylamine, N,N~diisopropylethylamine, and l,8-diazabicyclo[5,4,0]-unde-7- cene(DBU), or an inorganic base such as NaOH, Na₂CO₃, K₂CO₃ and Cs₂CO₃, is used in an equivalent or excess amount. The solvent used in the above reaction may be tetrahydrofuran, dioxane,

1,2-dimethoxyethane, dichloromethane, dimethylformamide (DMF), dimethylsulfoxide, or a mixture thereof. The reaction may be conducted at a temperature ranging from O ^°C to the boiling point of the solvent used.

Meanwhile, as shown in Reaction Scheme I, a compound of formula (Ilaa), which is the compound of formula (Ha) wherein L is Br, may be prepared by performing 1) nucleophilic substitution reaction and cyclization, and 2) amidation using a substituted benzonitrile derivative of formula (V) as a starting material. Representative examples of the compound of formula (V) may include o- fluorobenzonitrile, 6-chloro-2-nitrobenzonitrile and 2-chloro-3- pyridinecarbonitrile (e.g., currently marketed by Sigma- Aldrich).

reaction

and Cyclizatiou

wherein, R² , B, n, X, W and A have the same meanings as define formula (Ia); G is F or NO₂; and D is OH, Br or Cl.

As shown in Reaction Scheme I, in the nucleophilic substitution reaction and cyclization, a compound of formula (VI) may be prepared by reacting the compound of formula (V) with methyl glycolate or methyl thioglycolate in the presence of a base. The base may be an inorganic base such as sodium hydride, potassium ^-butoxide, sodium methoxide, K₂CO₃, NaOAc, KOAc, NaOH, KOH, Na₂CO₃, BaCO₃ and Cs₂CO₃ in an equivalent or excess amount, and the solvent used in the above reaction may be a ether-based solvent such as tetrahydrofuran, dioxane, 1,2-dimethoxyethane and dichloromethane, dimethylformamide (DMF), dimethylsulfoxide, or a mixture thereof. The reaction may be conducted at a temperature ranging from 0°C to the boiling point of the solvent used.

In Reaction Scheme I, when D is Br or Cl, the amidation may be conducted in the presence of a base in a manner similar to that described for the preparation of the compound of formula (Ia). When D is hydroxyl, the amidation may be conducted in the presence of a condensation agent such as 1,3- dicyclohexylcarbodiimide(DCC), l,3-diisopropylcarbodiimide(DIC), l-(3- dimethylaminopropyl)-3-ethylcarbodiimide(EDC), and 1, 1-carbonyldiimidazole (CDI), in a solvent such as dichloromethane, chloroform, tetrahydrofuran and DMF, at a temperature in the range of room temperature to the boiling point of the solvent used.

Also, a compound of formula (Iaa), which is the compound of formula (Ia) in which n is 1, may be prepared by conducting a 1,4-addition reaction of a compound of formula (VI) with an equivalent or excess amount of the compound of formula (III) in the presence of a suitable solvent and a base. The base and the reaction conditions may be those used in the preparation of the compound of formula (Ia).

wherein, R , B, Y, z, X, W, A and A' have the same meanings as defined in formula (Ia).

In this reaction, the compound of formula (IV) may be prepared by a conventional method of reacting the compound of formula (Ha) in which n is 1 with an equivalent or excess amount of a base, or alternatively by another conventional method of subjecting the compound of formula (VI) in Reaction Scheme I to an amidation reaction with an acryloyl halide. Further, other benzofuran or benzothiophene derivatives of the present invention may be prepared from the benzofuran or benzothiophene derivative substituted with amide of formula (Ia) through modification of the ester group, as shown in Reaction Scheme II.

wherein, R², B, n, Y, z, X, W₅ A and A' are the same as defined in formula Ia.

In Reaction Scheme II, the carboxylic acid derivative of formula (Ib) may be prepared by hydrolyzing the ester group of the compound of formula (Ia) using 1 to 5 equivalent amount of a base in a solvent, e.g., an alcohol such as methanol, an ether such as tetrahydrofuran and dioxane, and a mixture thereof. The base used in the above reaction is preferably sodium hydroxide or potassium hydroxide, and the reaction is conducted at a temperature in the range of O⁰C to the boiling point of the solvent used.

Further, the compound of formula (Ic) is prepared by reacting the compound of formula (Ib) with a condensation agent such as 1,3- dicyclohexylcarbodiimide(DCC), l,3-diisopropylcarbodiimide(DIC) and l-(3- dimethylaminopropyl)-3-ethylcarbodiimide(EDC), and then with 2- chloroethylamine hydrochloride in the presence of an equivalent or excess amount of a base. The solvent which can be used in this reaction is an ether such as tetrahydrofuran, dioxane, dichloromethane and 1,2-dimethoxyethane, dimethylformamide(DMF), dimethylsulfoxide, or a mixture thereof, while the base may be an organic base such as pyridine, triethylamine, N₃N- diisopropylethylamine, and DBU(1, 8-diazabicyclo[5,4,0]-unde-7-cene) or an inorganic base such as NaOH₅ Na₂CO₃, K₂CO₃, and Cs₂CO₃. The reaction is conducted at a temperature in the range of O ^°C to the boiling point of the solvent used.

Further, the present invention provides a pharmaceutical composition for preventing and treating ischemic diseases or protecting organs, comprising the compound of formula (I) or the pharmaceutically acceptable salt thereof as an active ingredient. The inventive pharmaceutical composition comprising the benzofuran or benzothiophene derivative of formula (I) or the pharmaceutically acceptable salt thereof may be administered in oral or parentally, and may be formulated with a diluent or excipient such as a filler, a thickening agent, a binder, a wetting agent, a disintegrant and a surfactant, in accordance with one of the known methods. In the present invention, the solid formulation for oral administration may be prepared by mixing at least one of the benzofuran or benzothiophene derivatives of formula (I) with at least one of excipients including starch, calcium carbonate, sucrose, lactose and gelatine. Besides, a lubricant such as magnesium stearate, talc and the like may be added, as well. Further, representative examples of the liquid formulations for oral administration may include suspensions, internal use solutions, emulsion and syrups, which may comprise a diluent such as water and liquid paraffin, and may further comprise various excipients including wetting agents, sweetening agents, aromatics and preservatives. For parentally administration, the inventive composition may be formulated into sterile aqueous solutions, non-aqueous solvents, suspensions, emulsions, lyopphilics and suppositories. The non-aqueous solvents and suspensions may comprise injectable vegetable oil (e.g., propylene glycol, polyethylene glycol and olive oil) and esters (e.g., ethyl olate), and the base materials for suppositories may comprise witepsol, macrogol, tween 61, cacao butter, laurin better, glycerol and gelatine. A proposed daily dose of the composition of the present invention for administration to a human (of approximately 70 kg body weight) is about from 0.1 mg/kg to 1000 mg/kg, more preferably about from 1 mg/kg to 500 mg/kg, and the inventive composition may be administered in a single dose or in divided doses per day. It should be understood that the daily dose should be determined in light of various relevant factors including the conditions to be treated, including age, body weight, sex, administration route, health state and disease severity; and, therefore, the dosage suggested above should not be construed to limit the scope of the invention in anyway.

The following Examples are intended to further illustrate the present invention without limiting its scope.

In the present invention, the molecular structures of the compounds were determined by infrared spectroscopy, NMR spectroscopy, mass spectroscopy, liquid chromatography, X-ray crystallography, optical rotation spectroscopy, elemental analysis, or comparison studies between the calculated values and the experimentally observed values of representative compounds.

Preparation Example 1: Preparation of 3-amino-benzofuran-2-carboxylic acid methyl ester

0.22 g (1.18 mmol) of σ-fluorobenzonitrile was dissolved in 5 ml of N₅N- dimethylformamide, 0.16 ml (2.18 mmol) of methyl glyconate and 0.62 g (4.54 mmol) of potassium carbonate were added thereto at room temperature, and the mixture was refluxed with heating for 12 hrs. After the reaction was completed, the reaction mixture was diluted with 10 ml of ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and concentrated under a reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate = 4:1) to obtain the title compound (0.10 g, 48% yield).

¹H NMR (300MHz, DMSO-d₆): δ 3.97(s, 3H), 4.98(s, 2H), 7.23-7.28(m, IH), 7.44-7.47(m, 2H), 7.56(d, IH)

Mass(m/e, M⁺): 192

Preparation Example 2: Preparation of 3-(2~bromo-acetyIamino)~ benzofuran-2-carboxylic acid methyl ester

0.75 g (3.92 mmol) of the compound obtained in Preparation Example 1 was dissolved in 5 ml of tetrahydrofuran, 1.09 g (7.84 mmol) of bromoacetic acid and 1.21 ml (7.84 mmol) of 1,3-diisopropyl carbodiimide were added thereto at room temperature, and the mixture was reacted for 5 hrs. After the reaction was completed, the reaction mixture was diluted with 10 ml of ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and concentrated under a reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate = 4:1) to obtain the title compound (0.96 g,

79% yield).

¹H NMR (300MHz, DMSO-d₆): δ 4.04(s, 2H), 4.12(s, 3H), 7.49-7.52(m, 3H), 7.32-7.36(m, 3H), 8.38(d, IH), 10.18(s, IH) MaSs(InZe₅ M⁺): 312, 314

Preparation Example 3: Preparation of 3-amino-4-chIoro-benzofuran-2- carboxylic acid methyl ester

The procedure of Preparation Example 1 was repeated except for using

513 mg (2.81 mmol) of 6-chloro-2-nitrobenzonitrile as a start material, and the residue was subjected to silica gel column chromatography(n-hexane: ethyl acetate = 10:1) to obtain 222 mg of the title compound (yield 35.0%).

¹H NMR (300 MHz, CDCl₃): δ 3.97 (s, 3H), 5.51 (brs, 2H), 7.17 (t, J = 4.2 Hz, IH), 7.34-7.35 (m, 2H) MS(m/e, M⁺): 224 Preparation Example 4: Preparation of 4-chloro-3-(2-chloro-acetyIamino)- benzofuran-2-carboxylic acid methyl ester

200 mg (0.89 mmol) of the compound obtained in Preparation Example 3 was dissolved in 3 ml of tetrahydrofuran, 0.37 ml(2.67 mmol) of triethylamine and 0.18 ml (2.23 mmol) of chloroacetyl chloride were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 2 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent, and the resulting solid was washed with, ether, filtered and dried to obtain 195 mg of the title compound (yield 73%).

¹H NMR (300 MHz, DMSO-^₆): δ 3.94 (s, 3H), 4.43 (s, 2H), 7.49 (d, J = 7.8 Hz, IH), 7.62 (t, J= 7.8 Hz, IH), 7.81 (d, J= 7.8 Hz, IH), 10.37 (brs, IH). MS(m/e, M⁺): 302

Preparation Example 5: Preparation of 3-acryIoylamino-benzofuran-2- carboxylic acid methyl ester

640 mg (3.35 mmol) of the compound obtained in Preparation Example 1 was dissolved in 3 ml of tetrahydrofuran, 1.48 ml (10.05 mmol) of triethylamine and 0.54 ml (6.70 mmol) of acryloyl chloride were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 1 hr. The reaction mixture was distilled under a reduced pressure to remove the solvent, followed by extracting the resulting mixture with ethyl acetate and aqueous NaCl. The separated organic layer was dried over anhydrous sodium sulfate, filtered, and distilled under a reduced pressure. The residue was subjected to column chromatography (hexane:ethyl acetate= 4:1) to obtain 590 mg (yield 72%) of the title compound.

¹H NMR (300 MHz₅ CDCl₃): δ 4.03(s, 3H), 5.88(d, IH), 6.36(m, 2H), 7.29(m, IH), 7.49(d, 2H), 8.51(d, IH), 9.57(Br, NH) MS(m/e, M⁺): 245 Preparation Example 6: Preparation of 3-(3-bromo-propionyIamino)-4- chIoro-benzofuran-2-carboxyIic acid methyl ester

241 mg (1.33 mmol) of the compound obtained in Preparation Example 3 was dissolved in 5 ml of N,N-dimethylformamide, 0.27 ml (2.66 mmol) of 3- bromopropionyl chloride was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 1 hr. The reaction mixture was distilled under a reduced pressure to remove the solvent, and the resulting solid was washed with ether, filtered, and dried to obtain 372 mg (yield 78%) of the title compound, 1H NMR (300 MHz, DMSO-ci₆): δ 3.05 (t, J= 6.6 Hz, 2H), 3.74 (t, J= 6.6

Hz, 2H), 3.89 (s, 3H), 7.42 (d, J= 7.5 Hz, IH), 7.55 (t, J= 8.4 Hz, IH), 7.74 (d, J = 8.4 Hz, IH), 10.09 (brs, IH) MS(m/e, M⁺): 360

Preparation Example 7: Preparation of 3-acryloylamino-4-chloro- benzofuran-2-carboxylic acid methyl ester

200 mg (0.56 mmol) of the compound obtained in Preparation Example 6 was dissolved in 3 ml of N,N-dimethylformamide, 0.23 ml (1.67 mmol, 3.0 eq) of triethylamine was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 2 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent, and the resulting solid was washed with ether, filtered and dried to obtain 140 mg (yield 90.9%) of the title compound.

¹H NMR (300 MHz, DMSO-^₆): δ 3.91 (s, 3H), 5.80 (d, J= 9.9 Hz, IH), 6.25 (d, J= 17.1 Hz, IH), 6.47-6.56 (m, IH), 7.40 (d, /= 7.8 Hz, IH), 7.55 (t, J= 8.4 Hz, IH), 7.74 (d, J= 8.4 Hz, IH), 10.13 (brs, IH)

Preparation Example 8: Preparation of 3-amino-furo[2,3,~#]pyridin-2- carboxylic acid methyl ester

The procedure of Preparation Example 1 was repeated except for using 600 mg (4.33 mmol) of 2-chloro-3-pyridinecarbonitrile as a start material, and the residue was subjected to silica gel column chromatography (hexane: ethyl acetate = 3:1) to obtain 105 mg of the title compound (yield 13 %).

¹H NMR (300 MHz, CDCl₃): δ 3.97 (s, 3H), 5.07 (brs, 2H), 7.24-7.28 (m, 2H), 7.96 (dd, J= 7.8, 1.8 Hz, IH), 8.51 (dd, J= 4.8, 1.8 Hz, IH) MS(m/e, M⁺): 192

Preparation Example 9: Preparation of 3-(2-chIoro-acetylamino)-furo[2,3r Z>]pyridin-2-carboxylic acid methyl ester

200 mg (1.0 mmol) of the compound obtained in Preparation Example 8 was dissolved in 5 ml of N,N-dimethylformamide, 0.17 ml (2.1 mmol, 2.0 eq) of chloroacetyl chloride was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 1 hr. The reaction mixture was distilled under a reduced pressure to remove the solvent, and the resulting solid was washed with ether, filtered and dried to obtain 241 mg (yield 86.4%) of the title compound.

¹H NMR (300 MHz, DMSO-J₆): δ 3.94 (s, 3H), 4.53 (s, 2H), 7.50 (dd, J= 8.1, 4.5 Hz, IH), 8.40 (dd, J= 8.1, 1.8 Hz, IH), 8.57 (dd, J= 4.5, 1.8 Hz, IH), 10.47 (brs, IH) MS(m/e, M⁺): 268

Preparation Example 10: Preparation of 3-acryIoyI-furo[2,3_>-^]pyridin-2- carboxylic acid methyl ester

The procedure of Preparation Example 5 was repeated using 531 mg (2.76 mmol) of the compound obtained in Preparation Example 8 to obtain 208 mg of the title compound (yield 31%).

¹R NMR (300 MHz, DMSO-J₆): δ 3.93 (s, 3H), 5.90 (dd, J= 10.2, 1.2 Hz, IH), 6.37 (d, J= 16.8 Hz, IH), 6.62 (dd, J= 16.8, 10.2, Hz, IH), 7.47 (dd, J= 8.1, 4.8 Hz, IH), 8.20 (d, J= 8.1 Hz, IH), 8.77 (dd, J= 4.8, 0.9 Hz, IH), 10.32 (brs, IH)

MS(m/e, M⁺): 246 Preparation Example 11: Preparation of 3-(2-bromo-2-phenyl-acetyIamino)- benzofuran-2-carboxyIic acid methyl ester

2.00 g (10.46 mmol) of the compound obtained in Preparation Example 1 was dissolved in 40 ml of dichloromethane, 6.75 g (31.38 mmol) of bromophenylacetic acid and 4.86 ml (31.38 mmol) of 1,3-diisopropyl carbodiimide were added thereto at room temperature, and the mixture was reacted for 24 hrs. After the reaction was completed, the reaction mixture was diluted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, and concentrated under a reduced pressure. The residue was subjected to silica gel column chromatography (hexane:ethyl acetate = 9:1) to obtain the title compound (1.75 g, 43% yield).

¹H NMR (300 MHz, DMSO): δ 4.02(s, 3H), 5.62(s, IH), 7.25-7.27(m, IH), 7.39-7.49(m, 5H), 7.52(d, 2H), 8.37(d, IH), 10.29(br, NH)

Preparation Example 12: Preparation of 3-[2-(4-bromo-phenylsuIfanyl)-2- phenyl-acetylamino]-benzofuran-2-carboxylic acid

1.7O g (3.42 mmol) of the compound obtained in Preparation Example 9 was dissolved in 30 ml of tetrahydrofuran, 2.57 ml (5.13 mmol, 1.5 eq) of 2 N NaOH was added dropwise thereto, and the mixture was stirred with heating under a nitrogen atmosphere for 24 hrs. The reaction mixture was acidified with 1 N HCl and extracted with ethyl acetate and aqueous NaCl, and the residue was subjected to subjected to silica gel column chromatography (10% methanol/ dichloromethane) to obtain 0.75 g of the title compound (yield 45%).

¹H NMR (300MHz, CDCl₃); δ 5.1 l(s, IH), 7.25-7.41(m, 9H), 7.49-7.60(m, 4H), 8.36(d, IH), 10.33(br, NH)

Preparation Example 13: Preparation of 3-[2-(4-bromo-phenylsulfanyI)-2- phenyI-acetyIamino]-benzofuran-2-carboxylic acid(2-chloro-ethyl)-amide 700 mg (1.45 mmol) of the compound obtained in Preparation Example

12 was dissolved in 15 ml of tetrahydrofuran, 471 mg (2.18 mmol) of di(2-

pyridyl)carbonate and 18 nig (0.15mmol, 0.1 eq) of dimethylaminopyridine were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 1 hr. After adding 0.60 ml (4.35 mmol) of triethyl amine and 510 mg (4.35 mmol) of 2-chloroethylamine hydrochloride thereto, the reaction mixture was stirred under a nitrogen atmosphere for 24 hrs, distilled under a reduced pressure to remove the solvent, and extracted with ethyl acetate and aqueous NaCl. The separated organic layer was dried over anhydrous sodium sulfate, filtered, and distilled under a reduced pressure, and the resulting residue was subjected to column chromatography (hexane:ethyl acetate = 4:1) to obtain 663 mg (yield

84%) of the title compound.

¹H NMR (300MHz, CDCl₃); δ 3.76(t, 2H), 3.88(t, 2H), 5.05(s, IH), 6.84(t, IH), 7.27(d, IH), 7.34-7.43(m, 8H), 7.56(d, 2H), 8.41(d, IH), 10.93(br, NH)

Preparation Example 14: Preparation of 3-amino-benzo[Z>]thiophene-2- carboxylic acid methyl ester

0.90 ml (8.26 mmol) of ø-fluorobenzonitrile was dissolved in 6 ml of N₃N- dimethylformamide, 0.90 ml (9.91 mmol) of methyl thioglyconate and 3.42 g

(24.78 mmol) of potassium carbonate was added thereto at room temperature, and the mixture was refluxed with heating for 12 hrs. After the reaction was completed, the reaction mixture was diluted with 10 ml of ethyl acetate, washed with water, dried over anhydrous magnesium sulfate, and concentrated under a reduced pressure. The resulting residue was subjected to silica gel column chromatography (hexane:ethyl acetate = 4:1) to obtain the title compound (1.53 g,

89% yield).

¹H NMR (300MHz, CDCl₃); δ 3.90(s, 3H), 5.87(br₅ 2H), 7.35(t, IH), 7.45(t, IH), 7.63(d, IH), 7.72(d, IH) MS(m/e, M⁺): 207

Preparation Example 15: Preparation of 3-(2-bromo-acetylamino)- benzo[£]thiophene-2-carboxyIic acid methyl ester

The procedure of Preparation Example 2 was repeated using 500 mg (2.42 mmol) of the compound obtained in Preparation Example 14, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 6:1) to obtain 356 mg of the title compound (45.0%). 1H NMR (300MHz₅ CDCl₃); δ 3.97(s, 3H), 4.27(s, 2H), 7.39(t, IH), 7.47(t,

IH), 7.77(d, IH), 7.99(d, IH), 10.14(br, NH) MS(m/e, M⁺): 327

Preparation Example 16: Preparation of 3-amino-4-chloro- benzo[#]thiophene-2-carboxyIic acid methyl ester

350 mg (1.92 mmol) of 6-chloro-2-nitrobenzonitrile was dissolved in 5 ml of N,N-dimethylformamide, 0.17 ml (1.92 mmol, 1.0 eq) of methyl thioglyconate and 192 mg (3.43 mmol, 1.8 eq) potassium hydroxide were added dropwise thereto at 0 °C , and the mixture was stirred under a nitrogen atmosphere at 0 °C for 1 hr. The reaction mixture was added to ice water, and the resulting solid was filtered to obtain 404 mg (87.3%) of the title compound.

¹H NMR (300 MHz, CDCl₃): δ 3.86 (s, 3H), 6.85 (brs, 2H), 7.28-7.35 (m, 2H), 7.60 (dd, J= 7.5, 0.8 Hz, IH) MS(m/e, M⁺): 241

Preparation Example 17: Preparation of 3-(2-chloro-acetylamino)-4-chloro- benzo[Z>]thiophene-2-carboxyIic acid methyl ester

The procedure of Preparation Example 4 was repeated using 241 mg (1.0 mmol) of the compound obtained in Preparation Example 16 to obtain 117 mg of the title compound (yield 37%).

¹B NMR (300 MHz, OMSO-d₆): δ 3.87 (s, 3H)₅ 4.37 (s, 2H), 7.54-7.58 (m, 2H), 8.05-8.10 (m, IH), 10.28 (brs, IH)

Preparation Example 18: Preparation of 3-acryloylamino-benzo[#]thiophene- 2-carboxyIic acid methyl ester

176 mg (0.85 mmol) of the compound obtained in Preparation Example 14 was dissolved in 3 ml of N,N-dimethylformamide, 0.10 ml (1.02 mmol) of 3- bromopropionyl chloride was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 24 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl, and the separated organic layer was dried over anhydrous sodium sulfate, filtered, and distilled under a reduced pressure. The residue was subjected to column chromatography (hexane:ethyl acetate = 6:1) to obtain 68 mg(yield 31%) of the title compound^'

¹U NMR (300 MHz, CDCl₃): δ 3.88 (s, 3H), 5.87 (dd, IH), 6.39(m, 2H), 7.41 (t, IH), 7.47(t, IH), 7.76(d, IH), 8.17(d, IH), 9.81(br, NH) MS(m/e, M⁺): 261

Preparation Example 19: Preparation of 3-(3-bromo-propionylamino)-4- chloro-benzo[#]thiophene-2-carboxylic acid methyl ester

241 mg (1.0 mmol) of the compound obtained in Preparation Example 16 was dissolved in 5 ml of N,N-dimethylformamide, 0.20 ml (2.02 mmol) of 3- bromopropionyl chloride was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 24 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent, and the resulting solid was washed with ether, filtered and dried to obtain 285 mg (yield 75.8%) of the title compound.

¹H NMR (300 MHz, DMSO-^₆): δ 3.04 (t, J= 6.6 Hz, 2H), 3.73 (t, J= 6.6 Hz, 2H), 3.91 (s, 3H), 7.51-7.61 (m, 2H), 8.06 (d, J= 6.3, 2.7 Hz, IH), 10.07 (brs, IH)

Preparation Example 20: Preparation of 3-acryloyIamino-4-chIoro- benzo[6]thiophene-2-carboxylic acid methyl ester

The procedure of Preparation Example 7 was repeated using 458 mg (1.22 mmol) of the compound obtained in Preparation Example 19 to obtain 266 mg of the title compound (yield 63%). 1H NMR (300 MHz, DMSO-^₆): δ 3.84 (s, 3H), 5.80 (d, J= 10.2 Hz, IH),

6.25 (d, J = 17.1 Hz, IH), 6.52 (dd, J = 17.1, 10.2 Hz, IH), 7.51-7.58 (m, 2H), 8.07 (dd, J= 6.6, 2.1 Hz, IH), 10.13 (brs, IH)

Preparation Example 21: Preparation of 3-(2-bromo-2-phenyI-acetylamino)- benzo[£]thiophene-2-carboxylic acid methyl ester

The procedure of Preparation Example 11 was repeated using 350 mg (1.69 mmol) of the compound obtained in Preparation Example 14 to obtain 232 mg (yield 34%) of the title compound. 1H NMR (300 MHz, DMSO): δ 3.95(s, 3H), 5.64(s, IH), 7.34(m,

5H), 7.65(m, 2H), 7.76(d, IH), 7.78(d, IH), 8.37(d, IH), 10.33(br, NH)

MS(m/e, M⁺): 405, 403

Preparation Example 22: Preparation of 3-amino-thiophene[2,3,-#]pyridin-2- carboxylic acid methyl ester

The procedure of Preparation Example 14 was repeated using 560 mg (3.07 mmol) of 2-chloro-3-pyridinecarbonitrile as a starting material, and the reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl. The separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure, and the resulting solid was washed with ether, filtered and dried to obtain 343 mg (yield 40.6%) of the title compound.

¹H NMR (300 MHz, CDCl₃): δ 3.91 (s, 3H), 5.93 (brs, 2H), 7.31 (dd, J = 8.2, 4.6 Hz, IH), 7.93 (dd, J= 8.2, 1.6 Hz, IH), 8.69 (dd, J= 4.6, 1.6 Hz, IH)

MS(m/e, M⁺): 208

Preparation Example 23: Preparation of 3-(2-chIoro-acetylamino)- thiophene[2,3,-#]pyridin-2-carboxyIic acid methyl ester

The procedure of Preparation Example 9 was repeated using 208 mg (1.0 mmol) of the compound obtained in Preparation Example 22, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 266 mg (yield

93.7%) of the title compound.

¹H NMR (300 MHz, DMSO-^₆): δ 3.90 (s, 3H), 4.51 (s, 2H), 7.58 (dd, J= 8.4, 4.5 Hz, IH), 8.27 (dd, J = 8.4, 1.8 Hz, IH), 8.79 (dd, J = 4.5, 1.8 Hz, IH), 10.69 (brs, IH)

MS(m/e, M⁺): 284

Preparation Example 24: Preparation of 3-acryloyIamino-thiophene[2,3,- #]pyridin-2-carboxyIic acid methyl ester

The procedure of Preparation Example 18 was repeated using 150 mg

(0.72 mmol) of the compound obtained in Preparation Example 22, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 266 mg

(yield 93.7%) of the title compound.

¹H NMR (300 MHz, DMSO-J₆): δ 3.87 (s, 3H), 5.87 (dd, J= 10.2, 1.8 Hz, IH), 6.33 (dd, J= 17.1, 1.8 Hz, IH), 6.62 (dd, J= 17.1, 10.2, Hz, IH), 7.55 (dd, J = 8.4, 4.8 Hz, IH), 8.20 (dd, J= 8.4, 1.5 Hz, IH), 8.77 (dd, J= 4.8, 1.5 Hz, IH), 10.47 (brs, IH)

Example 1: Preparation of 3-(2~phenylsuIfanyl-acetylamino)-benzofuran-2- carboxylic acid methyl ester

0.20 g (0.64 mmol) of the compound obtained in Preparation Example 2 was dissolved in 4 ml of tetrahydrofuran, 0.079 ml (0.77 mmol) of benzenethiol and 0.13 ml (0.96 mmol) of triethylamine were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 5 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl, and the separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure. The residue was subjected to column chromatography (hexane:ethyl acetate =4:1) to obtain 0.18 g (yield 80%) of the title compound.

¹H NMR (300MHz, DMSO-d₆) δ 3.86(s, 3H), 4.07(s, 2H), 7.24(t, 2H), 7.29-7.47(m, 4H), 7.53(t, IH), 7.69(t, 2H), 10.36(s, IH)

Mass(m/e, M⁺): 342

Example 2: Preparation of 3-[2-(4-bromo-phenylsuIfanyl)-acetylamino]- benzofuran-2-carboxyIic acid methyl ester

0.22 g (0.64 mmol) of the compound obtained in Preparation Example 2 was dissolved in 4 ml of tetrahydrofuran, 0.15 g (0.77 mmol) of 4- bromobenzenethiol and 0.13 ml (0.96 mmol) of triethylamine were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 5 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent, followed by extracting the resulting mixture with ethyl acetate and aqueous NaCl. The separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure, and the resulting residue was subjected to column chromatography (hexane:ethyl acetate = 4:1) to obtain

0.22 g (yield 84%) of the title compound.

¹H NMR (300MHz, DMSO-d*) δ 3.73(s, 3H), 3.94(s, 2H), 7.18(t, 2H), 7.28(d, 2H)₅ 7.38-7.43(m, 2H), 7.53(d, 2H), 10.23(s, IH) MaSS(InZe₅ M⁺) : 412, 399 Example 3: Preparation of 3-[2-(4-bromo-phenylsuIfanyI)-acetylamino]-4- chIoro-benzofuran-2-carboxyIic acid methyl ester

The procedure of Example 2 was repeated except for using 0.14 g (0.46 mmol) of the compound obtained in Preparation Example 4 and 129 mg (0.88 mmol) of 4-bromo benzenethiol, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 0.13 g (yield 62.7%) of the title compound.

¹H NMR (300 MHz, DMSO-^₆): δ 3.82 (s, 3H), 3.98 (s, 2H), 7.35-7.49 (m, 3H), 7.50-7.55 (m, 3H), 7.72 (d, J= 7.8 Hz, IH), 10.25 (brs, IH) MS(m/e, M⁺): 455

Example 4: Preparation of 3-[3-(4-bromo-phenylsulfanyl)-propionyIamino]- benzofuran-2-carboxylic acid methyl ester

The procedure of Example 1 was repeated except for using 0.10 g(0.41 mmol) of the compound obtained in Preparation Example 5 and 93 mg (0.49 mmol) of 4-bromo benzenethiol, and the resulting residue was subjected to silica gel column chromatography (n-hexane:ethyl acetate = 4:1) to obtain 0.13 g of the title compound (yield 75%).

¹H NMR (300 MHz, CDCl₃): δ 2.79 (t, 2H), 3.30 (t, 2H), 4.01 (s, 3H), 7.27 (m, 3H), 7.4 l(d, 2H), 7.48(d, 2H), 8.36 (d, IH), 9.36(br, NH)

MS(m/e, M⁺): 434

Example 5: Preparation of 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]- benzofuran-2-carboxyϋc acid

100 mg (0.24 mmol) of the compound obtained in Example 2 was dissolved in 10 ml of tetrahydrofuran, 0.36 ml (0.36 mmol) of 1 N aqueous NaOH was added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 2 hrs. The reaction mixture was acidified with 1 N HCl and extracted with ethyl acetate and aqueous NaCl, and the resulting residue was subjected to column chromatography(methanol:methylene chloride = 1 :10) to obtain 56 mg (yield 57%) of the title compound.

¹U NMR (300 MHz, CD₃OD): δ 3.81(s, 2H), 7.06(t, IH)₅ 7.19(m, 6H), 7.94(d, IH)

Example 6: Preparation of 4-chIoro-3-(3-(pyridin-2-yIsulfanyl)- propionylamino]-benzofuran-2-carboxylic acid methyl ester

125 mg (0.45 mmol) of the compound obtained in Preparation Example 7 was dissolved in 3 ml of N,N-dimethylformamide, 69 mg (0.63 mmol, 1.5eq) of 2-mercaptopyridine and 0.06 ml (0.45 mmol, l.Oeq) of triethyl amine were added dropwise thereto, and the mixture was stirred under a nitrogen atmosphere for 1 day. The reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl, and the separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure. The resulting residue was subjected to subjected to silica gel column chromatography (n-hexane:ethyl acetate= 2:1) to obtain 36 mg of the title compound (yield 21%). 1U NMR (300 MHz, DMSO-^₆): δ 2.77 (t, J= 7.2 Hz, 2H), 3.37 (t, J= 7.2

Hz, 2H), 3.82 (s, 3H), 7.08 (t, J= 5.7 Hz, IH), 7.27 (d, J= 7.8 Hz, IH), 7.36 (d, J = 7.8 Hz, IH), 7.49 (t, J= 7.8 Hz, IH), 7.61 (t, J= 7.2 Hz, IH), 7.68 (d, J= 8.4 Hz, IH), 8.42 (d, J= 3.6 Hz, IH), 10.17 (brs, IH)

Example 7: Preparation of 3-[2-(4-bromo-phenylsuIfanyI)~acetyIamino]- furo[2,3-#]pyridin-2-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 109 mg (0.41 mmol) of the compound obtained in Preparation Example 9, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 136 mg (yield

79.8%) of the title compound. ¹H NMR (300 MHz₅ DMSO-^₆): δ 3.91 (s, 3H), 4.11 (s, 2H), 7.40-7.55 (m, 3H), 7.54 (d, J= 8.7 Hz, 2H), 8.26 (d, J= 7.5 Hz, IH), 8.54 (d, J= 4.2 Hz, IH), 10.45 (brs, IH)

Example 8: Preparation of 3-(3-(pyridin-2-ylsulfanyl)-propionylamino]- furo[2,3-£]pyridin-2-carboxylic acid methyl ester

The procedure of Example 6 was repeated except for using 154 mg (0.63 mmol) of the compound obtained in Preparation Example 10, and the reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl. The separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure, and the resulting residue was subjected to column chromatography (Hex:EA=2:l) to obtain 91 mg (yield 40.8%) of the title compound. 1U NMR (300 MHz, CDCl₃): δ 3.00 (t, J= 6.9 Hz, 2H), 3.58 (t, J= 6.9 Hz,

2H), 4.00 (s, 3H), 7.00 (m, IH), 7.18-7.33 (m, 2H), 7.48 (m, IH), 8.46-8.53 (m, 2H), 8.92 (dd, J= 7.8, 1.5 Hz, IH), 9.62 (brs, IH)

Example 9: Preparation of 3-[2-(4-bromo-phenyIsulfanyl)-2-phenyl- acetylaminoj-benzofuran-l-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 1.75 g (4.50 mmol) of the compound obtained in Preparation Example 11, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 6: 1) to obtain 1.78 g of the title compound (yield 79%).

¹H NMR (300 MHz, DMSO): δ 3.99(s, 3H), 5.09(s, IH), 7.26-7.39(m, IH), 7.42-7.54(m, HH), 8.33(s, IH), 10.38(br, NH)

Example 10: Preparation of 2-(4-bromo-phenylsuIfanyI)-N-[2-(4,5-dihydro- oxazol-2-yl)-benzofιiran-3-yl]-2-phenyl-acetamide 100 mg (0.18 mmol) of the compound obtained in Preparation Example

13 was dissolved in 5 ml of tetrahydrofuran, 0.05 ml (0.27 mmol) of DBU was added dropwise thereto, and the mixture was refluxed with heating under a nitrogen atmosphere for 3 hrs. The reaction mixture was distilled under a reduced pressure to remove the solvent and extracted with ethyl acetate and aqueous NaCl₅ and the separated organic layer was dried over anhydrous sodium sulfate, filtered and distilled under a reduced pressure. The resulting residue was subjected to column chromatography (hexane: ethyl acetate^ 4:1) to obtain 50 mg

(yield 53%) of the title compound. 1H NMR (300 MHz, CDCl₃): δ 4.13(t, 2H), 4.46(t, 2H), 5.07(s, IH), 7.25-

7.44(m, 10H), 7.56(d, 2H), 8.30(d, IH), 10.58(br, NH)

Example 11: Preparation of 3-(2-phenylsuIfanyI-acetylamino)- benzo[b]thiophene-2-carboxyIic acid methyl ester

The procedure of Example 1 was repeated except for using 100 mg (0.31 mmol) of the compound obtained in Preparation Example 15, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 6:1) to obtain 65 mg of the title compound (yield 59%). 1U NMR (300 MHz, CDCl₃): δ 3.89(s, 3H), 3.91(s, 2H), 7.21(m, 4H),

7.44(m, 3H), 7.74(d, IH), 7.84(d, IH), 10.3 l(br, NH)

MS(m/e, M⁺): 357

Example 12: Preparation of 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]- benzo[b]thiophene-2-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 100 mg (0.31 mmol) of the compound obtained in Preparation Example 15, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 6: 1) to obtain 62 mg of the title compound (yield 46%).

¹H NMR (300 MHz, CDCl₃): δ 3.88(s, 2H), 3.90(s, 3H), 7.33(m, 6H)₃ 7.75(d, IH)₅ 7.84(d₅ IH), 10.28(br, NH) MS(m/e, M⁺): 435

Example 13: Preparation of 3-[2-(4-bromo-phenylsulfanyI)-acetylamino]-4- chloro-benzo[b]thiophene-2-carboxy!ic acid methyl ester

The procedure of Example 2 was repeated except for using 65 mg (0.21 mmol) of the compound obtained in Preparation Example 17, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 67 mg (yield

69.8%) of the title compound.

¹H NMR (300 MHz, DMSO-^₆): δ 3.83 (s, 3H), 3.99 (s, 2H), 7.38 (d, J = 8.4 Hz, 2H), 7.50-7.56 (m, 4H)₅ 8.06 (dd, J= 6.9, 2.4 Hz, IH), 10.23 (brs, IH)

Example 14: Preparation of 3-(3-phenylsulfanyl-propionylamino]- benzo[b]thiophene-2-carboxylic acid methyl ester

The procedure of Example 1 was repeated except for using 100 mg (0.38 mmol) of the compound obtained in Preparation Example 18, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 10:1) to obtain 85 mg of the title compound (yield 60%).

¹H NMR (300 MHz, CDCl₃): δ 2.83(t, 2H), 3.33(t, 2H), 3.93(s, 3H)₃ 7.23(m, 4H), 7.40(m, 3H), 7.49(d, IH), 8.07(d, IH), 9.49(br, NH)

MS(m/e, M⁺): 371

Example 15: Preparation of 3-[3-(4-bromo-phenylsulfanyl)-propionylamino]- benzo[b]thiophene-2-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 200 mg (0.77 mmol) of the compound obtained in Preparation Example 18, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 4:1) to obtain 225 mg of the title compound (yield 65%). ¹H NMR (300 MHz₅ CDCl₃): δ 2.81(t, 2H), 3.31(t, 2H), 3.94(s, 3H), 7.29(m₅ 3H), 7.43(m, 3H), 7.75(d, IH)₅ 8.05(d, IH)₅ 9.52(br, NH) MS(HiZe₅ M⁺)MS l

Example 16: Preparation of 4-chloro-3-(3-(pyridin-2-ylsulfanyl)- propionyIamino]-benzo[#]thiophene-2-carboxylic acid methyl ester

The procedure of Example 6 was repeated except for using 206 mg (0.69 mmol) of the compound obtained in Preparation Example 20, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 4:1) to obtain 60 mg of the title compound (yield 21%).

¹H NMR (300 MHz₅ DMSO-J₆): δ 2.82 (t₅ J= 7.2 Hz₅ 2H), 3.42 (t₅ J- 7.2 Hz₅ 2H), 3.86 (s, 3H)₅ 7.14 (t, J= 6.4 Hz₅ IH)₅ 7.32 (d₅ J= 7.8 Hz, IH)₅ 7.52-7.57 (m₅ 2H)₅ 7.66 (td, J= 7.8, 1.7 Hz, IH), 8.06 (dd, J= 6.4, 2.6 Hz₅ 2H), 8.48 (d, J= 4.8 Hz, IH)₅ 9.96 (brs₅ IH)

Example 17: Preparation of 3-[2-(4-bromo-phenyIsulfanyl)-2-phenyl- acetylamino]-benzo[b]thiophene-2-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 150 mg (0.37 mmol) of the compound obtained in Preparation Example 21, and the resulting residue was subjected to silica gel column chromatography(n-hexane: ethyl acetate = 2:1) to obtain 60 mg of the title compound (yield 21%).

¹H NMR (300 MHz₅ CDCl₃): δ 3.87(s, 3H), 5.12(s, IH)₅ 7.26(m, 9H)₅ 7.58(d₅ 2H)₅ 7.75(dd₅ 2H), 10.34(br, NH) MS(ITiZe₅ M⁺)^lS₅ SI l

Example 18: Preparation of 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]- thieno[2,3-Z>]pyridin-2-carboxylic acid methyl ester

The procedure of Example 2 was repeated except for using 143 mg (0.50 mmol) of the compound obtained in Preparation Example 23, and the reaction mixture was distilled under a reduced pressure to remove the solvent. The resulting solid was washed with ether, filtered and dried to obtain 158 mg (yield 71.8%) of the title compound.

¹U NMR (300 MHz, DMSO-J₆): δ 3.85 (s, 3H), 4.06 (s, 2H), 7.43 (d, J = 8.7 Hz, 2H), 7.50-7.56 (m, 3H), 8.00 (dd, J = 8.1, 1.5 Hz, IH), 8.75 (dd, J= 4.5, 1.5 Hz, IH), 10.57 (brs, IH) MS(m/e, M⁺): 438

Example 19: Preparation of 3-(3-(pyridin-2-yIsulfanyI)-propionylamino]- thieno[2,3-#]pyridin-2-carboxylic acid methyl ester

The procedure of Example 6 was repeated except for using 108 mg (0.42 mmol) of the compound obtained in Preparation Example 24, and the resulting residue was subjected to silica gel column chromatography (n-hexane: ethyl acetate = 2: 1) to obtain 34 mg of the title compound (yield 22%).

¹H NMR (300 MHz, CD₃OD): δ 2.98 (t, J = 6.9 Hz, 2H), 3.55 (t, J = 6.9 Hz, 2H), 3.91 (s, 3H), 7.08 (t, J= 5.7 Hz, IH), 7.30 (d, J= 8.1 Hz, IH), 7.46 (dd, J= 8.3, 4.6 Hz, IH), 7.61 (m, IH), 8.27 (dd, J= 8.3, 1.5 Hz, IH), 8.41 (d, J= 4.8 Hz, IH), 8.67 (dd, J= 4.6, 1.5 Hz, IH) MS(m/e, M⁺): 373

The benzofuran or benzothiophene derivatives substituted with amide of the present invention were assayed for pharmacological effects through the following experiments.

Test Example 1: Inhibitory effect on ischemic cell death

The benzofuran or benzothiophene derivatives of the present invention were each assayed for inhibitory activity against ischemic cell death in cells as follows.

Cardiomyocyte cell line H9c2 cells were cultured in DMEM (Dulbecco's modified Eagle's medium) supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin (10Ox solution). IxIO⁴ cells thus obtained were inoculated in 35 mm dishes and incubated at 37 ^°C for 48 hrs in a CO₂ incubator. The cells for control groups were then treated only with 0.1% DMSO and the cells for test groups treated with a DMSO solution of each of the derivatives of Examples 1 to 19 (10 μM) in DMSO. After 30 min, the cells were washed once with PBS.

While the cells were continuously treated with the DMSO solution (control group) or with 10 μM of the derivative solution (test group), together with a chemical hypoxia solution (106 mmol NaCl, 4.4 mmol KCl, 1 mmol MgCl₂, 38 mmol NaHCO₃, 2.5 mmol CaCl₂, 20 mmol 2-deoxy glucose, 1 mmol NaCN) for 1 to 2 hrs, the cell damage was observed by microscope. When some damages were observed, the cells were washed twice with 1 ml of PBS, and fixed with 1 ml of 3.7% formaldehyde. The cells thus obtained were washed with 1 ml of PBS again, stained with DAPI, and then washed three times with 1 ml of PBS. The extent of cell deaths (%) was determined using a fluorescence microscope.

The results are shown in Table 2 and FIG. 1. In the Table 2 and FIG. 1, "control" represents a group treated only with DMSO, and "cell," a group which is not treated with DMSO.

As shown in Table 2 and FIG. 1, the benzofuran or benzothiophene derivatives substituted with amide of the present invention showed significant inhibitory activities against ischemic cell death.

Test Example 2: Effect of benzofuran or benzothiophene derivative substituted with amide on a brain-disordered rat induced by temporary brain ischemia

The benzofuran or benzothiophene derivatives of the present invention were each assayed for the inhibitory activity against brain ischemia in the rat as follows.

Adult male Sprague-Dawley rats (200 to 250 g) were anesthetized using 75 mg/kg of ketamine and 5 mg/kg of rumpun, and divided into a control group (N=9) and a test group (N=9). Then, in order to induce a stroke caused by ischemia, the neck of the rat was incised along the midline thereof, and then, an external carotid artery (ECA), and an intermal carotid artery (ICA) located outside of the cranial cavity were isolated. Next, after a nylon ligature having a diameter of 0.37 mm was pushed from a commolon carotid artery (CCA) into about 20 to 22 mm in direction of ICA₅ the middle cerebral artery (MCA) was ligated to occlude its blood supply for 2 hrs. During the experiment, the body temperature of the rat was constantly maintained at 37.8 ^°C .

At 6 hrs after occlusion, 30 mg/kg of the compound of Example 1 was intraperitoneally administered, and at 28 days after stroke induction, the image of the rat model suffering from stroke was obtained by using a superconducting MRI with a 65 cm bore, operated on 3.0 T, wherein the fast spin echo (FSE), which is a kind of technique of high speed measurement technique, is used. The imaging parameters were as follows: the repetition image (TR), 4000 msec; the echo time,

96 msec; field of view (FOV), 60 mm; and the resolution, 128 x 128. Further, 15 slices with width of 2 mm was scanned and the scan was repeated 3 times per a slice. Next, brain infarct volumes (%) were calculated by using Osiris ver. 4.02 based on the image thus obtained.

Meanwhile, the above procedure was repeated for a comparative group which was treated with the compound of formula VII (KR-31378, Korea Research Institute of Chemical Technology), which has been known to inhibit the ischemic cell death [Lee, M. H. et al., Res. Commun. MoI. Pathol. Pharmacol. 110: 361-370, 2001; Hong, K. W. et al, J. Pharmacol. Exp. Ther. 301:210-216, 2002].

The results are shown in Table 3 below and FIG. 2. In the Table 3 and FIG. 2, "control" represents a group treated only with DMSO.

As shown in Table 3 and FIG. 2, the benzofuran or benzothiophene derivative of the present invention (e.g., Example 2) showed remarkable inhibitory activities against ischemic cell death of the brain-disordered rat induced by a temporary brain ischemia.

The formulation of the present invention, comprising the benzofuran or benzothiophene derivative as an active ingredient, are illustrated in the following Formulation Examples, but are not construed to limit the scope of the present invention.

Formulation Example 1: Tablet (Direct Compression)

5.0 mg of the inventive benzofuran or benzothiophene derivative was sieved, mixed with 14.1 mg of lactose, 0.8 mg of crospovidone USUF and 0.1 mg of magnesium stearate, and compressed into a tablet.

Formulation Example 2: Tablet (Wetting Formulation)

5.0 mg of the inventive benzofuran or benzothiophene derivative was sieved, and mixed with 16.0 mg of lactose and 4.0 mg of starch. A suitable amount of a solution prepared by dissolving 0.3 mg of polysolvate 80 in purified water was added thereto, followed by granulation. Next, the resulting granule was dried, sieved, mixed with 2.7 mg of colloidal silicon dioxide and 2.0 mg of magnesium stearate, and compressed into tablets.

Formulation Example 3: Powder and Capsule

5.0 mg of the inventive benzofuran or benzothiophene derivative was sieved, and mixed with 14.8 mg of lactose, 10.0 mg of polyvinyl pyrrolidone and 0.2 mg of magnesium stearate. The mixture was filled in a hard gelatine capsule No. 5, using a suitable apparatus.

Formulation Example 4: Injection solution An injection was prepared by mixing 100 mg of the inventive benzofuran or benzothiophene derivative, 180 mg of mannitol, 26 mg of Na₂HPO₄- 12H₂O and 2974 mg of distilled water.

While the invention has been described with respect to the above specific embodiments, it should be recognized that various modifications and changes may be made and also fall within the scope of the invention as defined by the claims that follow.

Claims

WHAT IS CLAIMED IS:

1. A benzofuran or benzothiophene derivative of formula (I), or a pharmaceutically acceptable salt thereof:

wherein,

R¹ is -CO₂R² or , R² being H or a straight, branched or cyclic chain Q-

C₆ alkyl;

B is H, or phenyl optinally substituted with halogen or C₁-C₃ alkyl; n is an integer ranging from 0 to 2;

Y is S; z is H or halogen;

X is O or S;

W is H or halogen; and

A and A' are each independently CH or N.

2. The compound of claim I₅ wherein R² is H, methyl or ethyl; and n is 0 or 1.

3. The compound of claim 1, wherein the benzofuran or benzothiophene derivative of formula (I), or the pharmaceutically acceptable salt thereof is selected from the group consisting of:

1) 3-(2-phenylsulfanyl-acetylamino)-benzofuran-2-carboxylic acid methyl ester;

2) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-benzofuran-2-carboxylic acid methyl ester;

3) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-4-chloro-benzofuran-2-carboxylic acid methyl ester;

4) 3-[3-(4-bromo-phenylsulfanyl)-propionylamino]-benzofuran-2-carboxylic acid methyl ester;

5) 3 - [2-(4-bromo-phenylsulfanyl)-acetylamino] -benzofuran-2-carboxylic acid;

6) 4-chloro-3-(3-(pyridin-2-ylsulfanyl)-propionylamino]-benzofuran-2-carboxylic acid methyl ester;

7) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-furo[2,3-b]pyridin-2-carboxylic acid methyl ester;

8) 3 -(3 -(pyridin-2-y lsulfanyl)-propionylamino] -fiiro [2,3 -b]pyridin-2-carboxylic acid methyl ester;

9) 3-[2-(4-bromo-phenylsulfanyl)-2-phenyl-acetylamino]-benzofuran-2- carboxylic acid methyl ester;

10) 2-(4-bromo-phenylsulfanyl)-N-[2-(4,5-dihydro-oxazol-2-yl)-benzofuran-3- yl]-2-phenyl-acetamide;

12) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-benzo[b]thiophene-2-carboxylic acid methyl ester;

13) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-4-chloro-benzo[b]thioρhene-2- carboxylic acid methyl ester;

14) 3-(3-phenylsulfanyl-propionylamino]-benzo[b]thioρhene-2-carboxylic acid methyl ester;

15) 3-[3-(4-bromo-phenylsulfanyl)-propionylamino]-benzo[b]thiophene-2- carboxylic acid methyl ester;

16) 4-chloro-3-(3-(pyridin-2-ylsulfanyl)-propionylamino]-benzo[b]thiophene-2- carboxylic acid methyl ester;

17) 3-[2-(4-bromo-phenylsulfanyl)-2-ρhenyl-acetylamino]-benzo[b]thiophene-2- carboxylic acid methyl ester;

18) 3-[2-(4-bromo-phenylsulfanyl)-acetylamino]-thieno[2,3-b]pyridin-2- carboxylic acid methyl ester; and

19) 3-(3-(pyridin-2-ylsulfanyl)-propionylamino]-thieno[2,3-έ]pyridin-2-carboxylic acid methyl ester.

4. A method for preparing the compound of claim 1, comprising the step of reacting a compound of formula (II) with a compound of formula (III) to obtain a benzofuran or benzothiophene derivative of formula (I):

wherein, R¹, B, n, Y, z, X, W, A and A' have the same meanings as defined in claim 1; and L is a leaving group.

5. A pharmaceutical composition for preventing or treating an ischemic disease, which comprises the compound of claim 1 as an active ingredient.

6. The composition of claim 5, wherein the ischemic disease is selected from the group consisting of brain ischemia, heart ischemia, diabetic cardiovascular disease, heart failure, myocardial hypertrophy, retinal ischemia, ischemic colitis, ischemic acute renal failure, stroke, head trauma, Alzheimer's disease, Parkinson's disease, neonatal hypoxia, glaucoma, and diabetic neuropathy.

7. The composition of claim 6, wherein the ischemic disease is induced by hypoxemia.

8. A pharmaceutical composition for protecting organs, which comprises the compound of claim 1 as an active ingredient.