JP2011168515A - 2-arylbenzoxazole compound having erythropoietin production-promoting action - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low molecular compound having an EPO production-promoting action. <P>SOLUTION: There is provided an EPO production-promoting agent containing a 2-arylbenzoxazole compound represented by general formula (1) (wherein, ring A is phenyl, naphthyl or quinolinyl; R<SP>1</SP>, R<SP>2</SP>are each identically or differently H, a 1 to 6C alkyl or amino; R<SP>3</SP>, R<SP>4</SP>are each identically or differently H, a halogen atom, a 1 to 6C alkyl, a 1 to 6C alkoxy, a 6 to 10C aryl, amino or OH), or a salt thereof, or their solvates as an active ingredient. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a novel erythropoietin production promoter. More specifically, the present invention relates to a preventive and / or therapeutic agent for diseases caused by decreased production of erythropoietin, such as anemia.

  Erythropoietin (EPO) is a glycoprotein hormone involved in the maturation and differentiation of erythroid progenitor cells into mature erythrocytes, and is a naturally occurring monomeric polypeptide consisting of 165 amino acids (Non-patent Document 1). ).

  Human EPO is essential for the growth and differentiation of erythrocytes and is useful for the treatment of blood diseases characterized by a decrease in erythrocyte production. Clinically, EPO is found in patients with chronic renal failure (CRF) who are treated for anemia, self-contained blood, and premature infant anemia (Non-Patent Documents 2-4), in cancer patients undergoing AIDS and chemotherapy. (Non-patent Document 5). EPO has also been shown to be effective in chronic anemia.

  EPO is produced mainly in the kidney in adults, but it is also produced in astrocytes and neurons in the central nervous system, and EPO and EPO receptors are expressed in capillaries at the brain-periphery boundary. In addition, systemic administration of EPO has been reported to cross the blood brain barrier and reduce neuronal cell loss in response to brain and spinal cord ischemia, mechanical trauma, epilepsy, excitotoxins and neuroinflammation. (Non-Patent Documents 6 to 10).

  In the therapy using a protein such as EPO, in order to maintain a therapeutically effective concentration of the compound in the circulation and a short plasma half-life due to being susceptible to protease degradation (Non-patent Documents 11 and 12) There are problems such as having to make internal injections frequently. In addition, there is subcutaneous injection as an administration route instead of intravenous injection, but since the absorption from the administration site is slow, there is a sustained release effect, but the plasma concentration is significantly lower than that of intravenous injection. Therefore, in order to obtain the same therapeutic effect, the same number of injections as in the case of intravenous injection must be performed, which is a burden on the patient. In addition, human serum EPO is a glycoprotein, and the structure of the sugar chain bound to the surface of EPO is complex, and its glycosylation is extensive and diverse. However, human serum EPO cannot be produced with good reproducibility.

  Therefore, there is a need in the art for methods and compounds that increase endogenous EPO, rather than low bioavailability EPO, in the treatment of diseases caused by reduced EPO production including anemia as described above.

  On the other hand, it is known that the production amount of EPO is controlled by the oxygen concentration via a hypoxia-inducible factor (HIF) that is a transcription factor (Non-patent Document 13). That is, under normal atmospheric conditions, the HIF subunit (HIF-1α) in which the proline residue is hydroxylated by 2-oxoglutarate dioxygenase enzyme is degraded by the ubiquitin-proteasome system, and the production of EPO is not promoted. Below, hydroxylation of the proline residue of HIF-1α by the 2-oxoglutarate dioxygenase enzyme is suppressed, and as a result, the stabilized HIF-1α moves from the cytoplasm into the nucleus and dimerizes with HIF-1β. It forms a body and binds to the hypoxia responsive element (HRE) sequence of the EPO gene to promote transcription and promote production of EPO.

  Enzyme inhibitors for HIF prolyl hydroxylase such as 2-oxoglutarate dioxygenase enzyme utilizing such an EPO production mechanism have been reported as EPO production promoters (Patent Documents 1 to 4).

  However, genes whose production is controlled by HIF include not only genes encoding EPO but also genes encoding vascular endothelial growth factor (VEGF). It has also been reported that VEGF has an angiogenesis-promoting action and can cause malignant tumors to deteriorate through this function (Non-Patent Documents 14 and 15). In addition, since anemia is also caused by cancer chemotherapy, and an anemia treatment drug may be administered to a cancer patient receiving such chemotherapy (Non-patent Document 6), VEGF worsens cancer. Such a risk is included in a compound having an inhibitory action on HIF prolyl hydroxylase enzyme activity that may also promote the production of and the like.

  The production of EPO is controlled by a promoter located on the 5 'side of EPO and an enhancer located on the 3' side, and HIF is considered to bind to the HRE sequence in the enhancer and promote the production of EPO. In addition, GATA-2, NFκB, and the like are also considered to control EPO production (Non-patent Documents 16 and 17), and it is considered that EPO production promotion can be achieved by an action mechanism other than inhibition of HIF prolyl hydroxylase enzyme activity. Therefore, a compound having an EPO production promoting action independent of inhibition of HIF prolyl hydroxylase enzyme activity is considered useful in the treatment of anemia.

  In addition, as described above, EPO promotes proliferation and maturation of erythroid progenitor cells, but a compound having an action of promoting maturation / differentiation of erythroid progenitor cells without involving production of EPO is also a therapeutic agent for anemia. Useful as. Compounds that have an activity to enhance blood cell proliferation promoting action of EPO and compounds that have an inhibitory action on hematopoietic cell phosphatase that catalyzes dephosphorylation, which is one of the important control mechanisms of EPO signaling, have been reported. (Patent Documents 5 to 7), the activity is not always sufficient. Furthermore, although synthetic peptides and hematides that act on the EPO receptor have been reported (Non-patent Document 18), a high dose is required for the expression of activity equivalent to EPO, and it is not suitable for oral administration. There is.

  Therefore, an orally administrable low-molecular-weight anemia treatment agent having an EPO production promoting action is considered useful in future anemia treatment.

  On the other hand, those having a 2-arylbenzoxazole skeleton related to the present invention include an antidepressant (Non-patent document 19), an antibacterial agent (Patent document 8, Non-patent document 20, Non-patent document 21), Duschenne muscular dystrophy. Therapeutic agent (Patent Document 9), anti-inflammatory agent (Patent Document 10, Patent Document 11), anticancer drug (Non-Patent Document 22, Non-Patent Document 23), hyperlipidemia therapeutic agent (Patent Document 12), iron chelator ( Nonpatent literature 24), Alzheimer's therapeutic agent (nonpatent literature 25), etc. are known. However, there is no description or suggestion regarding an action for promoting anemia treatment or erythropoietin production in any of the documents.

JP 2006-137763 A WO2003 / 53997 pamphlet WO2005 / 11696 pamphlet WO2007 / 38571 pamphlet Special Table 2000-536365 JP-A-11-171774 JP 2002-275159 A WO2009 / 80788 pamphlet WO2009 / 21748 pamphlet JP 2008-81460 A WO2007 / 91313 pamphlet Japanese Patent Publication No. 08-505847

Lin F-K, et al., Proc. Natl. Acad. Sci. USA, 82: 7580-7584 (1985) Eschbach JW, et al., N. Engl. J. Med, 316: 73-78 (1987) Eschbach JW, et al., Ann. Intern. Med., 111: 992 (1989) Lim VS, et al., Ann. Intern. Med., 110: 108-114 (1989) Danna RP, et al., Erythropoietin in Clinical Applications-An International Perspective, New York: Marcel Dekker; p301-324 (1990) Sakanaka M, et al., Proc. Natl. Acad. Sci. USA., 95, 4635-4640 (1998) Celik M, et al., Proc. Natl. Acad. Sci. USA., 99, 2258-2263 (2002) Brines ML, et al., Proc. Natl. Acad. Sci. USA., 97, 10526-10531 (2000) Calapai G, et al., Eur. J. Pharmacol., 401, 349-356 (2000) Siren A-L, et al., Proc. Natl. Acad. Sci. USA., 98, 4044-4049 (2001) Spivack JL and Hogans BB, Blood, 73: 90 (1989) McMahon FG, et al., Blood, 76: 1718 (1990) Jelkman W, Internal Medicine 43, 649-659 (2004) Maxwell PH, et al., Proc. Natl. Acad. Sci. USA. 94, 15, 8104-8109 (1997) Fang J, et al., Cancer Res., 61, 15, 5731-5735 (2001) Imagawa S, et al., Blood 89, 1430-1439 (1997) La Ferla K, et al., FASEB J, 16, 1811-1813 (2002) Stead RB, et al., Blood, 108, 1830-1834 (2006) Myllymaki MJ, et al., Eur. J. Med. Chem., 44, 4179-4191 (2009) Ursu O, et al., Croat. Chem. Acta, 79, 483-488 (2006) Yalcin I, et al., Eur. J. Med. Chem., 25, 705-708 (1990) Mutoh M, et al., Carcinogenesis, 29, 824-829 (2008) Chua MS, et al., J. Med. Chem., 42, 381-392 (1999) Grady RW, et al., J. Pharmacol. Exp. Ther., 205, 757-765 (1978) Johnson SM, et al., J. Med. Chem., 51, 260-270 (2008)

  An object of the present invention is to provide a compound having a low molecular weight EPO production promoting action. More specifically, the object is to provide a medicament useful for the prevention and / or treatment of anemia.

  In view of the above circumstances, as a result of eager search for a compound having an EPO production promoting action, the present inventors have found that a 2-arylbenzoxazole compound represented by the following general formula (1) is a HepG2 cell derived from human liver cancer. It was found that the EPO production was promoted in the test used, and the present invention was completed.

  That is, the present invention provides the following general formula (1):

[Where:
A ring represents a phenyl group, a naphthyl group or a quinolinyl group,
R ¹ and R ² may be the same or different and each represents a hydrogen atom, a C _1-6 alkyl group or an amino group,
R ³ and R ⁴ may be the same or different and each represents a hydrogen atom, a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _6-10 aryl group, an amino group or a hydroxyl group]
It is related with the EPO production promoter which uses the 2-aryl benzoxazole compound represented by these, its salt, or those solvates as an active ingredient.

More specifically, the present invention provides the following compound group:
2-phenylbenzoxazol-5-amine,
5-amino-2- (benzoxazol-2-yl) phenol,
2- (2-chloro-5-iodophenyl) benzoxazol-5-amine,
2- (4-chlorophenyl) benzoxazol-5-amine,
2- (3-chlorophenyl) benzoxazol-6-amine,
2- (4-iodophenyl) benzoxazol-5-amine,
2- (o-toluyl) benzoxazole,
2- (4-methoxyphenyl) benzoxazole,
2- (m-toluyl) benzoxazol-5-amine,
5-amino-2- (5-methylbenzoxazol-2-yl) phenol,
3- (5,7-dimethylbenzoxazol-2-yl) aniline,
4- (5-ethylbenzoxazol-2-yl) aniline,
2-methyl-4- (5-methylbenzoxazol-2-yl) aniline,
2- (quinolin-2-yl) benzoxazole,
2- (quinolin-4-yl) benzoxazole,
2- (5-bromonaphthalen-1-yl) benzoxazol-5-amine,
2- (naphthalen-2-yl) benzoxazol-5-amine,
2- (2-methylquinolin-4-yl) benzoxazole,
The EPO production promoter selected from the group consisting of 2-[(1,1′-biphenyl) -4-yl] benzoxazole and 2- (quinolin-4-yl) benzoxazole is provided.

  The present invention also relates to a prophylactic and / or therapeutic agent for anemia comprising the 2-arylbenzoxazole compound represented by the general formula (1) or a salt thereof, or a solvate thereof as an active ingredient. More specifically, the present invention provides a prophylactic and / or therapeutic agent for anemia comprising a 2-arylbenzoxazole compound selected from the above group of compounds, or a salt thereof, or a solvate thereof as an active ingredient. It is.

  The present invention also relates to the use of the 2-arylbenzoxazole compound represented by the general formula (1) or a salt thereof, or a solvate thereof for producing a preparation for promoting EPO production (use). About. More specifically, the present invention provides the use of a 2-arylbenzoxazole compound selected from the aforementioned group of compounds, or a salt thereof, or a solvate thereof, for producing a preparation for promoting EPO production. Is.

  Furthermore, the present invention administers an effective amount of the 2-arylbenzoxazole compound represented by the general formula (1), or a salt thereof, or a solvate thereof to a patient who is required to promote production of EPO. The present invention relates to a method for promoting EPO production. More specifically, the present invention administers an effective amount of a 2-arylbenzoxazole compound selected from the aforementioned compound group, or a salt thereof, or a solvate thereof to a patient in need of promoting production of EPO. The present invention provides a method for promoting EPO production.

  In addition, the present invention is directed to contacting cells with an effective amount of the 2-arylbenzoxazole compound represented by the general formula (1), or a salt thereof, or a solvate thereof, to produce EPO in the cells. It relates to a method to promote. More specifically, the present invention relates to the production of EPO in a cell by contacting the cell with an effective amount of a 2-arylbenzoxazole compound selected from the aforementioned compound group, or a salt thereof, or a solvate thereof. It provides a way to promote. Here, the term “contact” as used herein means that the 2-arylbenzoxazole compound or the like of the present invention has an uptake action or interaction on the cell surface by the cell in vitro or in vivo. This means that the compound or the like is added to cells so as to regulate cell functions such as proliferation, differentiation, and secretion of physiologically active substances.

  Furthermore, the present invention relates to production of EPO comprising the 2-arylbenzoxazole compound represented by the general formula (1), or a salt thereof, or a solvate thereof, and a pharmaceutically acceptable carrier. It is related with the pharmaceutical composition for promoting. More specifically, the present invention relates to a 2-arylbenzoxazole compound selected from the aforementioned group of compounds, or a salt thereof, or one or more compounds of solvates thereof, and a pharmaceutically acceptable carrier. And a pharmaceutical composition for promoting the production of EPO.

  The present invention has found a 2-arylbenzoxazole compound, or a salt thereof, or a solvate thereof having an excellent EPO production promoting action, and the symptoms are improved by promoting EPO production. Diseases (e.g., anemia in patients with chronic renal failure, anemia of premature blood, premature infant anemia, anemia in cancer patients undergoing AIDS and chemotherapy, chronic anemia, iron deficiency anemia, aplastic anemia, hemolytic anemia, It is useful as a pharmaceutical composition for the prevention and / or treatment of anemia such as megaloblastic anemia). The present invention also provides a preventive and / or therapeutic agent for anemia comprising an orally administrable low molecular weight compound having an EPO production promoting action as an active ingredient.

  Hereinafter, the present invention will be described in detail.

  The definitions of terms in the present invention are as follows.

  As used herein, “halogen atom” means a halogeno group, specifically a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

As used herein, an “alkyl group” may be linear or branched. Therefore, “C _1-6 alkyl group” includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, Isopentyl group, neopentyl group, 4-methylbutyl group, 1-ethylpropyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group 2,2-dimethylbutyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group And a straight chain or branched alkyl group having 1 to 6 carbon atoms.

As used herein, an “alkoxy group” may be linear or branched. Accordingly, “C _1-6 alkoxy group” includes methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group. And straight-chain or branched alkoxy groups having 1 to 6 carbon atoms such as a group and an n-hexyloxy group.

As used herein, “C _6-10 aryl group” means a monocyclic or condensed cyclic aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an azulenyl group. .

  Other groups not defined here follow the usual definitions.

  In general formula (1), the naphthyl group in the A ring is preferably a naphthalen-2-yl group.

  In general formula (1), the quinolinyl group in the A ring is preferably a quinolin-2-yl group or a quinolin-4-yl group.

In the general formula (1), the C _1-6 alkyl group in R ¹ and R ² is preferably a C _1-4 alkyl group, and more preferably a methyl group or an ethyl group.

In general formula (1), as a halogen atom in R < ³ >, R < ⁴ >, a chlorine atom, a bromine atom, or an iodine atom is preferable.

In the general formula (1), the C _1-6 alkyl group in R ³ and R ⁴ is preferably a C _1-4 alkyl group, and more preferably a methyl group.

In the general formula (1), the C _1-6 alkoxy group in R ³ and R ⁴ is preferably a C _1-4 alkoxy group, and more preferably a methoxy group.

In general formula (1), the C _6-10 aryl group in R ³ and R ⁴ is preferably a phenyl group.

  Specific examples of the 2-arylbenzoxazole compound represented by the general formula (1) of the present invention include the following compounds.

  The 2-arylbenzoxazole compound represented by the general formula (1) of the present invention, or a salt thereof, or a solvate thereof is not only a 2-arylbenzoxazole compound of the present invention but also a pharmaceutically acceptable product thereof. It includes salts, various hydrates and solvates thereof, crystalline polymorphs thereof, and substances that become prodrugs of these substances.

  As a pharmaceutically acceptable salt of the 2-arylbenzoxazole compound represented by the general formula (1) of the present invention, specifically, when the compound is treated as a basic compound, an inorganic acid (for example, hydrochloric acid, Hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, etc.) and organic acids (eg formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, lactic acid, malic acid) , Tartaric acid, citric acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, aspartic acid, glutamic acid, etc.) and the like, and when treating the compound as an acidic compound, an inorganic salt (for example, Sodium salt, potassium salt, lithium salt, barium salt, calcium salt, magnesium salt, etc.) and organic salt (eg pyridinium salt, picolinium salt, triethyla Moniumu salt, etc.) and the like.

  Examples of the solvate of the 2-arylbenzoxazole compound represented by the general formula (1) of the present invention or a pharmaceutically acceptable salt thereof include hydrates and various solvates (for example, alcohols such as ethanol and the like). Solvate).

  The 2-arylbenzoxazole compound represented by the general formula (1) of the present invention is prepared by a known method (for example, Eur. J. Med. Chem., 25 (8), 705-8 (1990); J. Med). Chem., 51, 260-270 (2008), etc.) or a method based thereon can be produced as a reference. Although an example of a manufacturing method is shown below, the manufacturing method of the compound of this invention is not limited to this.

[Wherein R ¹ , R ² , R ³ , R ⁴ represent the same as described above, and R ⁵ represents a halogen atom or a hydroxyl group]

[When R ⁵ is Halogen] The 2-aminophenol derivative (2) and the compound (3) are reacted in an appropriate solvent in the presence of a base to form an amide, followed by a ring-closing reaction in the presence of an acid. Thus, the compound (1) of the present invention can be produced. The base used in this reaction is preferably an organic base such as triethylamine, diisopropylethylamine, pyridine, lutidine, collidine, and more preferably pyridine. As the acid, sulfonic acids such as p-toluenesulfonic acid are preferable. As the solvent, aromatic hydrocarbon solvents such as benzene, toluene and xylene are preferable, and toluene is more preferable. The reaction conditions vary depending on the raw materials and solvent used, but in the amide formation step, the reaction may be performed at 0 to 50 ° C., preferably 10 to 40 ° C., for 1 minute to 24 hours, preferably 3 minutes to 6 hours. In the ring closing step, the reaction may be performed at 60 to 150 ° C., preferably 80 to 120 ° C., for 30 minutes to 24 hours, preferably 30 minutes to 6 hours.

[When R ⁵ is a hydroxyl group] The compound (1) of the present invention can be produced by subjecting the 2-aminophenol derivative (2) and the compound (3) to a ring-closing reaction in the presence of an acid. As the acid used in this reaction, sulfonic acids such as p-toluenesulfonic acid are preferable. As the solvent, aromatic hydrocarbon solvents such as benzene, toluene and xylene are preferable, and toluene is more preferable. While the reaction conditions vary depending on the raw materials and solvent used, the reaction may be carried out at 60 to 150 ° C., preferably 80 to 120 ° C., for 30 minutes to 24 hours, preferably 30 minutes to 6 hours. In addition, you may use a condensing agent for this reaction for the purpose of accelerating reaction. Such condensing agents include dicyclohexylcarbodiimide (DCC), 1,1-carbonyldiimidazole (CDI), bis (2-oxo-3-oxazolidinyl) phosphine chloride (BOP-Cl), 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and the like can be mentioned, and CDI is more preferable.

  Moreover, the compound (1) of this invention can also be manufactured by reacting 2-aminophenol derivative (2) and a compound (3) in polyphosphoric acid. The reaction conditions in the reaction using polyphosphoric acid vary depending on the raw materials and the solvent to be used, but are usually 80 to 300 ° C., preferably 120 to 280 ° C., and 30 minutes to 24 hours, preferably 1 to 6 hours. .

Further, for the purpose of avoiding side reactions, the substituents (R ^{1 to} R ⁴ ) of the compound (1) are protected with an appropriate protecting group, and deprotection is carried out after completion of the reaction step. ) Can also be manufactured. As the protection and deprotection conditions for the substituent, a generally used method (Protective Groups in Organic Synthesis Third Edition, John Wiley & Sons, Inc.) can be used as a reference.

  Intermediates and target products obtained in the above reactions are necessary for purification methods commonly used in organic synthetic chemistry, such as filtration, extraction, washing, drying, concentration, recrystallization, various chromatography, etc. Can be isolated and purified. In addition, the intermediate can be subjected to the next reaction without any particular purification.

  Furthermore, various isomers can be isolated by a conventional method utilizing the difference in physicochemical properties between isomers. For example, the racemic mixture is obtained by a general racemic resolution method such as a method of optical resolution by introducing a diastereomeric salt with a general optically active acid such as tartaric acid, or a method using optically active column chromatography. Can lead to optically pure isomers. Further, the diastereomeric mixture can be divided by, for example, fractional crystallization or various chromatography. An optically active compound can also be produced by using an appropriate optically active raw material.

  The EPO production promoter or anemia treatment / prevention agent of the present invention contains a 2-arylbenzoxazole compound represented by the general formula (1), a salt thereof, or a solvate thereof as an active ingredient. It can be used as a pharmaceutical composition. In that case, the compound of the present invention may be used alone, but it is usually used in combination with a pharmaceutically acceptable carrier and / or diluent.

  The administration route is not particularly limited, but can be appropriately selected depending on the purpose of treatment. For example, any of oral preparations, injections, suppositories, inhalants and the like may be used. Pharmaceutical compositions suitable for these dosage forms can be produced by utilizing known preparation methods.

  When preparing an oral solid preparation, a pharmaceutically acceptable excipient for the 2-arylbenzoxazole compound represented by the general formula (1), and further, if necessary, a binder, a disintegrant, a lubricant, After adding a coloring agent, a flavoring agent, a flavoring agent and the like, tablets, coated tablets, granules, powders, capsules and the like can be produced by utilizing conventional methods. Additives may be those commonly used in the art. Examples of excipients include lactose, sucrose, sodium chloride, glucose, starch, calcium carbonate, kaolin, microcrystalline cellulose, silicic acid and the like. Examples of the binder include water, ethanol, propanol, simple syrup, glucose solution, starch solution, gelatin solution, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropyl starch, methylcellulose, ethylcellulose, shellac, calcium phosphate, and polyvinylpyrrolidone. Examples of the disintegrant include dry starch, sodium alginate, agar powder, sodium hydrogen carbonate, calcium carbonate, sodium lauryl sulfate, stearic acid monoglyceride, and lactose. Examples of the lubricant include purified talc, stearate, borax, and polyethylene glycol. Examples of the corrigent include sucrose, orange peel, citric acid, tartaric acid and the like.

  When preparing a liquid preparation for oral administration, a liquid preparation for oral administration is prepared by adding a corrigent, a buffer, a stabilizer, a corrigent and the like to the 2-arylbenzoxazole compound represented by the general formula (1). Syrups, elixirs and the like can be produced. As the corrigent, those mentioned above may be used. Examples of the buffer include sodium citrate, and examples of the stabilizer include tragacanth, gum arabic, and gelatin.

  When preparing an injection, a pH regulator, a buffer, a stabilizer, an isotonic agent, a local anesthetic, etc. are added to the 2-arylbenzoxazole compound represented by the general formula (1). Can be used to produce subcutaneous, intramuscular and intravenous injections. Examples of the pH adjusting agent and buffer include sodium citrate, sodium acetate, sodium phosphate and the like. Examples of the stabilizer include sodium pyrosulfite, EDTA, thioglycolic acid, thiolactic acid and the like. Examples of local anesthetics include procaine hydrochloride and lidocaine hydrochloride. Examples of isotonic agents include sodium chloride and glucose.

  When preparing a suppository, a carrier for a suppository known to the 2-arylbenzoxazole compound represented by the general formula (1), such as polyethylene glycol, lanolin, cocoa butter, fatty acid triglyceride, etc., if necessary After adding a surfactant (for example, Tween (registered trademark)) or the like, it can be produced using a conventional method.

  In addition to the above, it is possible to appropriately prepare a preferable preparation using a conventional method.

  The dose of the 2-arylbenzoxazole compound represented by the general formula (1) of the present invention varies depending on age, body weight, symptom, dosage form, frequency of administration, etc. It is preferred that 1 mg to 1000 mg per day as the represented compound is administered orally or parenterally in one or several divided doses.

  EXAMPLES Next, although an Example is given and this invention is further demonstrated, this invention is not limited to these Examples. The test compounds used in the examples were those obtained from Chembridge.

Example 1
The EPO production promoting activity of the 2-arylbenzoxazole compound of the present invention was measured based on the EPO promoter activity.

<Materials and methods>
A vector in which the 5 ′ promoter region and 3 ′ enhancer region of human EPO were linked to the luciferase gene of pGL3 basic (Promega) was introduced into a cell line HepG2 derived from human liver cancer by lipofection. The obtained stable expression strain (HepG2 EPO-luc) was used for the evaluation of the test compound. Next, 5 × 10 ³ cells of HepG2 EPO-luc were seeded in each well of a 96-well plate using a minimum essential medium (MEM) (Sigma) containing 10% fetal bovine serum. Thereafter, the test compound dissolved in DMSO was added to each well so as to have a final concentration of 10 μM, and the amount of the medium was adjusted to 100 μl per well. After incubation for 24 hours in a CO ₂ incubator with an oxygen concentration of 4%, Bright-Glo ™ Luciferase Assay System (Promega) was added at 100 μl / well as EPO promoter activity, and immediately using ARVO (Perkin Elmer) The luciferase activity was measured. The above method was in accordance with the instruction manual attached to the Bright-Glo (trademark) Luciferase Assay System.

  The EPO promoter activity (% of control) induced by each compound was calculated with the EPO promoter activity in an unstimulated state without addition of the compound as 100%. The results are shown in Table 4.

<Result>
EPO production was promoted by adding a test compound at a concentration of 10 μM (see Table 4). In particular, Compound 14 had a strong EPO production promoting action exceeding 1900%. From the above, it has been clarified that these compounds have an EPO production promoting action, and it was found that they are useful as an anemia treatment agent.

  The present invention for the first time finds that the 2-arylbenzoxazole compound represented by the general formula (1) or a salt thereof, or a solvate thereof has an excellent EPO production promoting action. The present invention provides an orally administrable preventive and / or therapeutic agent for low molecular weight anemia having a production promoting action. The present invention provides a novel low-molecular-weight anemia prevention and / or treatment agent, which is useful in the pharmaceutical industry and has industrial applicability.

Claims (3)

The following general formula (1):

[Where:
A ring represents a phenyl group, a naphthyl group or a quinolinyl group,
R ¹ and R ² may be the same or different and each represents a hydrogen atom, a C _1-6 alkyl group or an amino group,
R ³ and R ⁴ may be the same or different and each represents a hydrogen atom, a halogen atom, a C _1-6 alkyl group, a C _1-6 alkoxy group, a C _6-10 aryl group, an amino group or a hydroxyl group]
The EPO production promoter which uses the 2-arylbenzoxazole compound represented by these, its salt, or those solvates as an active ingredient. The following compound groups:
2-phenylbenzoxazol-5-amine,
5-amino-2- (benzoxazol-2-yl) phenol,
2- (2-chloro-5-iodophenyl) benzoxazol-5-amine,
2- (4-chlorophenyl) benzoxazol-5-amine,
2- (3-chlorophenyl) benzoxazol-6-amine,
2- (4-iodophenyl) benzoxazol-5-amine,
2- (o-toluyl) benzoxazole,
2- (4-methoxyphenyl) benzoxazole,
2- (m-toluyl) benzoxazol-5-amine,
5-amino-2- (5-methylbenzoxazol-2-yl) phenol,
3- (5,7-dimethylbenzoxazol-2-yl) aniline,
4- (5-ethylbenzoxazol-2-yl) aniline,
2-methyl-4- (5-methylbenzoxazol-2-yl) aniline,
2- (quinolin-2-yl) benzoxazole,
2- (quinolin-4-yl) benzoxazole,
2- (5-bromonaphthalen-1-yl) benzoxazol-5-amine,
2- (naphthalen-2-yl) benzoxazol-5-amine,
2- (2-methylquinolin-4-yl) benzoxazole,
The EPO production promoter according to claim 1, which is selected from the group consisting of 2-[(1,1'-biphenyl) -4-yl] benzoxazole and 2- (quinolin-4-yl) benzoxazole.   A prophylactic and / or therapeutic agent for anemia comprising the EPO production promoter according to claim 1 or 2 as an active ingredient.