BACKGROUND Most of non-steroid anti-inflammatory drugs represent actions such as anti-inflammation, analgesic, and antipyretic activity by inhibiting the enzymatic activity of cyclooxygenase or prostaglandin G/H synthase. In addition, they can suppress the uterine contraction induced by hormones and the cell proliferation in several kinds of cancers. Firstly, only cyclooxygenase-1 (COX-1), found in cow as a constitutional enzyme, was known. But recently, cyclooxygenase-2 is identified to be discriminated clearly from cyclooxygenase-1 and can be provoked easily by mitogen, endotoxin, hormones, growth factors, cytokines and the like.

Prostaglandins have various pathological and physiological functions. Precisely, cyclooxygenase-1 as a constitutional enzyme participates in the secretion of basic endogenous prostaglandin and plays an important

role in physiological aspects such as stomach homeostasis, renal blood circulation and so on. On the other hand, cyclooxygenase-2 is induced by inflammatory factors, hormones, growth factors, cytokines and the like, and thus plays an important role in pathological effects of prostaglandin. Therefore, selective inhibitors against cyclooxygenase-2 are expected to have no side effect on account of the functional mechanism compared with the anti-inflammatory drugs such as conventional non-steroid agents and to represent actions such as antiphlogistic, analgesic and antipyretic activity. Furthermore, it is estimated to suppress the uterine contraction induced by hormones and the cell proliferation in several kinds of cancers. Especially, it probably has a few side effects such as gastrointestinal toxicity, renal toxicity and the like. Also, it is assumed to prevent the synthesis of contractive prostanoids, and thus inhibit the contraction of smooth muscle induced by the prostanoid. Hence, it can be applied usefully to treat a premature birth, dysmenorrhea, asthma and several diseases associated with eosinophilic leukocytes. Besides, it can be widely exploited to cure osteoporosis, glaucoma, large intestine cancer, prostatic carcinoma and athymia, which has been disclosed in many references, especially the usefulness of selective inhibitors against cyclooxygenase-2 (References: John Vane,"Towards a better aspirin"in Nature, Vol. 367, p215-216, 1994; Bruno Battistini, Regina

Botting and Y. S. Bakhle,"COX-1 and COX-2: Toward the Development of More Selective NSAIDs"in Drug News and Perspectives, Vol. 7, p501-512, 1994; Urology, Vol. 58, pl27, 2001; David B. Reitz and Karen Seibert,"Selective Cyclooxygenase Inhibitors"in Annual Reports in Medicinal Chemistry, James A. Bristol, Editor, Vol. 30, pl79-188, 1995).

The selective inhibitors against cyclooxygenase-2 have been reported to have various structure forms.

Among these, the diaryl heterocycle structure, namely a tricyclic system, has been studied most frequently and exploited to construct a lot of candidate substances. In this structure, it is essential that sulfonamide or methanesulfone group exist onto one phenyl group.

U. S. Pat. No. 5,466, 823 disclosed celecoxib, the compound of the following formula 36. The celecoxib is a substituted pyrazolyl benzonesulfonamide derivative.

Formula 36> WO Pub. No. 95/00501 disclosed rofecoxib, the compound of the following formula 37. The rofecoxib has the same diaryl heterocycle structure as celecoxib of the formula 36, but the heterocycle structure is furanone structure.

Formula 37>

U. S. Pat. No. 5,633, 272 disclosed valdecoxib, the compound of the following formula 38. The valdecoxib has the same phenyl sulfonamide structure as celecoxb of the formula 37, but the heterocycle structure is isoxazole structure.

Formula 38>

The forgoing compounds of the formula 36,37 and 38 have antiphlogistic and analgesic effect without side effects comparing with the conventional non-steroid anti- inflammatory drugs as a selective cyclooxygenase-2 inhibitor.

DISCLOSURE OF INVENTION Based upon the above technical backgrounds, the inventors of the present invention have tried in order to develop novel compounds as a highly selective cyclooxygenase-2 inhibitor. As a result, it is found that isothiazole derivatives satisfy such a purpose.

Therefore, an object of the present invention is to provide isothiazole derivatives or nontoxic salts of isothiazole derivatives.

Another object of the present invention is to provide a method for preparing isothiazole derivatives'or nontoxic salts of isothiazole derivatives.

And a further object of the present invention is to provide pharmaceutical compositions with antipyretic, analgesic and antiphlogistic activity containing isothiazole derivatives or nontoxic salts of isothiazole derivatives as an effective component.

Hereinafter, the present invention will be described more clearly.

The present invention relates to an isothiazole derivative of the following formula 1 or its nontoxic salt.

<Formula 1>

wherein, Ri is hydrogen, alkoxy or halogen; and R2 is methyl or amino group.

The compound of the present invention can be existed as a nontoxic salt form, wherein the nontoxic salt means a pharmaceutically acceptable nonpoisonous salt including an organic salt and inorganic salt.

Also, the compound of the present invention can be existed as a pharmaceutically acceptable salt form of an organic acid or inorganic acid. The organic acid or inorganic acid includes, but is not limited to, acetic acid, adipic acid, aspartic acid, 1,5-naphthalenedisulfonic acid, benzenesulfonic acid, benzoic acid, camposulfonic acid, citric acid, 1,2-ethanedisulfonic acid, ethanesulfonic acid, ethylenediaminetetraacetic acid, fumaric acid, glucoheptonic acid, gluconic acid, glutamic acid, hydriodic acid, hydrobromic acid, hydrochloric acid, icethionic acid, lactic acid, maleic acid, malic acid, manderic acid, methanesulfonic acid, music acid, 2-naphthalenedisulfonic acid, nitric acid, oxalic acid, parnoic acid, pantothenic acid, phosphoric acid, pivalic acid, propionic acid, salicylic acid, stearic acid, succinic acid, sulfuric acid, tartaric acid, p-toluenesulfonic acid, undecanoic acid and 10-undecenoic acid. And preferable acids are succinic acid, hydrobromic acid, hydrochloric acid, maleic acid, methanesulfonic acid, phosphoric acid, sulfuric acid or tartaric acid.

More preferably, the isothiazole derivative or

nontoxic salt thereof according to the present invention can be a compound selected from a group consisting of 4- (4-fluorophenyl)-3- (4- methanesulfonylphenyl)-5-methyl-isothiazol,<BR> 4- (5-methyl-3-phenyl-isothiazole-4-yl)- benzonesulfonamide, 4- [3- (4-bromophenyl)-5-methyl-isothiazlole-4-yl]- benzenesulfonamide, 4- [3- (4-methoxyphenyl)-5-methyl-isothiazole-4-yl]- benzenesulfonamide, 4- [3- (4-fluorophenyl)-5-methyl-isothiazole-4-yl]- benzenesulfonamide, 4- (4-methanesulfonylphenyl)-5-methyl-3-phenyl- isothiazole, 3- (4-bromophenyl)-4- (4-methanesulfonylphenyl)-5- methyl-isothiazole, 3- (4-methoxyphenyl)-4- (4-methanesulfonylphenyl)-5- methyl-isothiazole, and 3- (4-fluorophenyl)-4- (4-methanesulfonylphenyl)-5- methyl-isothiazole ; or nontoxic salt thereof.

The present invention includes a method for preparing the compound of the following formula la including the reaction step for adding ammonia water to the compound of the following formula 7.

Formula 7> Formula la>

wherein Ri is hydrogen, alkoxy or halogen.

The solvent used in the reaction includes, but is not limited to, dichloromethane, tetrahydrofuran (THF), benzene, toluene and the like.

The reaction can be accomplished by reacting at room temperature or by refluxing at boiling point depending upon compounds.

Also, the present invention includes a method for preparing the compound of the following formula lb including the step for reacting the compound of the formula 7 with hydrazine and methyl iodide.

<Formula lb>

The solvent used in the reaction includes, but is not limited to, dichloromethane, THF, benzene and the like.

The reaction can be accomplished by reacting at room temperature or by refluxing at boiling point depending upon compounds.

The compound of the formula 7 can be prepared as illustrated schematically in the following reaction formula 1.

<Reaction Formula 1> aO NOH O \ I NON \ n-butyl lithium NH20H. Cl acetic anhyride (2) (3) (4) l H2 Hz N ; S CIS03H S lH2 O ~ s nu2 0 , s N CIS03H NA/P2s5 S02C (7) (6) As demonstrated in the above reaction formula 1, the

compound of the formula 7 can be prepared through five steps.

In the first step, dioxybenzoine (2) as initial material is reacted with hydroxylamine hydrochloride to prepare oxime compound (3). A base used in the above reaction can be selected from, but not limited to, sodium acetate, potassium hydroxide, sodium hydroxide, potassium carbonate and the like. Among these, potassium hydroxide can be used more preferably. The solvent used in this step procedure can be a conventional solvent used in an organic synthesis. Representative examples of such solvents are, but not limited to, toluene, ethanol, methanol, dimethylformamide, n-methylpyrrolidione and the like. Among these, ethanol is more preferable.

In the second step, oxime compound (3) from the first step is reacted with n-butyl lithium and acetic anhydride to prepare isoxazole compound. A solvent used in the present reaction can be a conventional non-reactive organic solvent used in an organic synthesis. Among these, THF is more preferable.

In the third step, isoxazole compound (4) from the second step is treated with active metals and hydrogen gas to prepare a compound (5) having an open-ring compound of isoxazole via a hydrogenation. The active metal used in this step procedure includes, but not limited to, Raney Nickel, Pd/C of 10 %, and the like. Among these, Raney Nickel is more preferable. Also, a solvent used in the

present reaction can be a conventional non-reactive organic solvent used in hydrogenation. Preferably, the mixture of THF and methanol can be used. In addition, it is the most preferable to complete the reaction at room temperature.

In the forth step, isothiazole compound (6) is prepared by adding phosphorus pentasulfide and sodium carbonate to the compound (5), and the reaction is carried out at room temperature, and then 2,3, 5.6-tetrachloro- 1, 4-benzonequinone (chloranil) is added thereto, followed by refluxing. A solvent used in the present reaction can be a conventional non-reactive organic solvent used in an organic synthesis. Among these, tetrahydrafurane is more preferable.

In the last step, the compound of the formula 7 is prepared by adding chlorosulfonic acid to isothiazole compound (6), and cooling to about-5C, and then the reaction is completed.

Also, the present invention includes a method for preparing the compound of the following formula lc including the step for reacting the compound of the formula 12 with phosphorus pentasulfide and 2,3, 5.6-tetrachloro- 1,4-benzoquinone : <Formula 12> <Formula lc>

The solvent used in the above reaction includes, but is not limited to, THF, ethyl acetate, DMF and the like.

And the reaction is preferably carried out in the presence of a base and the base can be, but not limited to, sodium carbonate and the like.

Besides, the reaction can be accomplished by reacting at room temperature or by refluxing at boiling point depending upon compounds.

The compound of the formula 12 can be prepared as illustrated schematically in the following reaction formula 2.

<Reaction Formula 2>

As demonstrated in the above reaction formula 2, the compound of the formula 12 can be prepared through three steps.

In the first step, 4-methanesulfonyl benzoic acid (9) is reacted with propane-2-one compound (8) substituted with benzyl group on 1 position thereof to prepare the compound of the formula 10. The reaction is carried out in the presence of a base and the base can be selected from, but not limited to, sodium hydroxide, sodium methoxide, sodium t-buthoxide and the like. Among these, sodium hydroxide is most preferable. Also, a solvent used in this step can be a conventional non-reactive organic solvent used in an organic synthesis. Representative examples of such solvents are, but not limited to benzene, toluene, xylene, dimethylformamide, n-methylpyrrolidone and the like. Among these, dimethylformamide is most preferable.

In the second step, the compound of the formula 10 is reacted with hydroxyl ammine hydrochloride to prepare the compound of the formula 11. And the reaction can be accomplished under the same condition as the method for preparing the isoxzole compound (4) of the reaction formula 1.

In the last step, the compound of the formula 11 is treated with active metal and hydrogen gas to prepare an opern-ring compound of isoxazole via a hydrogenation. The active metal used in this step includes, but not limited to, Raney Nickel, Pd/C of 10 %, and the like. Among these, Raney Nickel is more preferable. Also, this reaction is carried out under the organic solvent used conventionally for hydrogenation. Preferably, the mixture of THF and methanol can be used. In addition, it is the most preferable to complete the reaction at room temperature.

In all the reactions illustrated above, a separation and purification of the resulting products can be processed through a common treatment used in an organic synthesis such as concentration, extraction and the like, and specially, can be carried out by using column chromatography on silica gel phase.

The present invention provides a pharmaceutical composition with antipyretic, analgesic and antiphlogistic activity, including a therapeutically effective amount of an isothiazole derivative or nontoxic salt thereof as an effective component and a pharmaceutically acceptable

carrier.

This pharmaceutical composition can be used for antipyretic, analgesic and antiphlogistic agents, which can minimize side effects due to containing the compound of the formula 1 having an activity for selective inhibition against cyclooxygenase-2 or its pharmaceutically acceptable salts.

Conventional non-steroid antiphlogistic agent has showed many side effects, because it inhibits non- selectively cox-1 participating in the secretion of basic endogenous prostaglandin and playing an important role in physiological aspects such as stomach homeostasis, renal blood circulation and so on, as well as cox-2 involving in synthesis of pathological prostaglandin.

On the other hand, the compound of the formula 1 and pharmaceutically acceptable salt thereof has a selective inhibition activity against cox-2, so that they can minimize the side effect that conventional non-steroid antipyretic, analgesic and antiphlogistic agent has showed.

Therefore, the pharmaceutical composition containing the compound of the formula 1 or non-toxic salt thereof, and pharmaceutically acceptable carries or excipients can be a substitute for conventional non-steroid anti- inflammatory drugs. Concretely, it improves side effects of conventional non-steroid antipyretic, analgesic and antiphlogistic agent, and is useful for patients suffering from peptic ulcer, gastritis, partial enteritis, ulcerative

colitis, diverticulitis, gastrointestinal haemorrhagia, hypoprothrombinemia and the like.

The pharmaceutical composition according to the present invention is useful for treating all the inflammatory diseases related to pathological prostaglandin, and particularly osteoarthritis and rheumatoid arthritis to be administrated in high amount.

Also, the pharmaceutical composition can be administrated to an adult in an amount of 5 to 400 mg/kg on the basis of a compound of formula 1 or non-toxic salt thereof, but the administration amount can be varied depending upon the seriousness of diseases.

In addition, the pharmaceutical composition can be administrated in a tablet formulation, a forming-tablet formulation, a capsule formulation, a granule formulation, a powder formulation, an extended-release tablet formulation, an extended-release capsule formulation (a single and a multiple unit), an ampul formulation for intravenous and intramusclar injection, an injection formulation, a suspension formulation, a suppository formulation, or any other suitable pharmaceutical formulations.

The extended-release formulation can include an active compound in a full form with initial administration content, or a partial form without initial administration content.

The active compound can be administrated by

individual administration method or stepwise administration method by time unit, depending upon existing together therewith, or partially or fully being separated from other ingredients in the formulation.

In case that the active compound is fully separated from other ingredients in the formulation, the active compound is combined to other ingredients, so that in administration unit, it is contained in the same amount or the corresponding weight ratio as being able to exist in the combined mixture.

Especially, the orally administrated pharmaceutical composition including the indicated combined mixture is preferable.

In order to prepare the pharmaceutical formulation including the combined mixture, the active compound is formulated in the indicated amount by a preferable method with excipients, diluents and/or adjuvants having physiological tolerance.

The examples of the excipients, and adjuvants are natural sugar such as gelatin, saccharose and lactose, lecithin, pectin, starch such as cornstarch, amylose, cyclodextrin, cyclodextrin's derivative, dextran, polyvinylpyrrolidone, polyvinylacetate and gum Arabic, alginic acid, talc, salicylic acid, calcium hydrogen phosphate, cellulose, cellulose's derivative such as methoxypropylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxypropylmethylcellulose.

phthalate, Cl2-C22 fatty acids, emulsifying agent, oil and fatty, especially, vegetable glycerol ester of saturated fatty acid and polyglycerol ester, monohydric or polyhydric alcohols and polyglycol such as polyethylene glycol, C1-C20 aliphatic alcohol, or ester of aliphatic saturated or unsaturated C2-C22 fatty and polyhydric alcohols such as glycol, glycerol, diethylene glycol, 1,2-propylene glycol, sorbitol.

Additionally, the suitable adjuvants are disintergrant, corss-linked polyvinylpyrrolidone, sodium carboxymethyl starch, sodium carboxymethyl cellulose and microcrystalline cellulose. And the disclosed coating material such as acrylic acid, methacrylic acid and/or ester polymer and copolymer thereof, zein, ethylcellulose, ethylcellulose succinate, shellac and the like can be used.

Suitable plasticizer as the coating material can be ester of citric acid and tartaric acid, glycerol and ester of glycerol, and polyethylene glycol having diverse chain length. In preparing the solution or suspension, water or physiologically acceptable organic solvents such alcohol and aliphatic alcohol can be used suitably.

In the liquid formulation, preservatives such as potassium sorbate, methyl 4-hydroxybenzoate and propyl 4- hydroxybenzoate, antioxidant such as ascorbic acid, and aromatic such like peppermint oil can be used.

In preparing the formulation, the disclosed conventional dissolvent such as polyvinylpyrrolidone and

polysorbate 80, and emulsifying agent can be used.

Any other examples of the suitable excipients and adjuvants are referred in"Lexikon der Hilfsstoffe fur Pharmazie, Kosmetik und angrenzende Gebiete (Encyclopaedia of auxiliaries for pharmacy, cosmetics and related fields)" by Dr. H. P. Fiedler.

MODES FOR CARRYING OUT THE INVENTION Practical and presently preferred embodiments of the present invention are illustrated as shown in the following Examples.

However, it will be appreciated that those skilled in the art, on consideration of this disclosure, may make modifications and improvements within the spirit and scope of the present invention.

Reference Example 1> Preparation of 1, 2-diphenyl-ethanone oxime Formula 13> 20g of dioxybenzoin was dissolved in anhydrous ethanol 100ml, and 9. 21g of hydroxylamine hydrochloride and 7.43g of potassium hydroxide was added thereto, and then the solution was refluxed for 6 hours to complete the reaction.

The reaction solution was cooled to room temperature, diluted in water 200ml and extracted with ethyl acetate to separate an organic layer. The separated organic layer was dried with anhydrous magnesium sulfate and the solvent was evaporated under reduced pressure to yield a light yellow liquid phase. The liquid phase was re-crystallized in ethanol and water. As a result, 17.7g of the compound of the formula 13 (yield: 82%) was obtained as a solid phase.

1H-NMR (400MHz, CDC13) 4.12 (s, 2 H), 7.10-7. 15 (m, 1 H), 7.20-7. 30 (m, 4 H), 7.40-7. 50 (m, 3 H), 7.60-7. 65 (m, 2 H), 8.20 (bs, 1 H) Melting Point: 87-90°C Reference Example 2> Preparation of 1- (4-bromophenyl)-2- phenyl-ethanone oxime <Formula 14> The reaction was carried out through the same method as Reference Example 1, except employing 2. 0g of 1- (4-bromo phenyl) -2-phenyl ethanone instead of dioxybenzoin. As a result, 1.53g of the compound of the formula 14 (yield: 75%) was obtained as a light color solid phase.

1H NMR (400 MHz, CDC13) 4.12 (s, 2 H), 7.05-7. 10 (m, 1 H), 7.19 (d, 2 H, J = 8.2 Hz), 7.30-7. 38 (m, 4 H), 7.50 (d, 2

H, J = 8.2 Hz), 8. 20 (bs, 1 H) Melting Point: 122-125C <Reference Example 3> Preparation of 1-(4-methoxyphenyl)-2- phenyl-ethanone oxime Formula 15> The reaction was carried out through the same method as Reference Example 1, except employing l. Og of 1- (4- methoxy phenyl)-2-phenyl ethanone instead of dioxybenzoin.

As a result, 0.58g of the compound of the formula 15 (yield: 54%) was obtained as a light color solid phase.

1H NMR (400 MHz, CDC13) 3.90 (s, 3 H), 4.12 (s, 2 H), 6.90 (d, 2 H, J = 8.4 Hz), 7.05-7. 10 (m, 1 H), 7.30-7. 38 (m, 4 H), 7.50 (d, 2 H, J = 8.4 Hz), 8.18 (bs, 1 H) Melting Point: 132-135C Reference Example 4> Preparation of 1- (4-fluorophenyl)-2- phenyl-ethanone oxime Formula 16>

The reaction was carried out through the same method as Reference Example 1, except employing 2. 0g of 1- (4- <BR> flourophenyl) -2-phenyl ethanone instead of dioxybenzoin.

As a result, 1.35g of the compound of the formula 16 (yield: 63%) was obtained as a light color solid phase.

IH NMR (400 MHz, CDC13) 4.12 (s, 2 H), 7.05-7. 15 (m, 3 H), 7.30-7. 38 (m, 4 H), 7.40 (d, 2 H, J = 8.4 Hz), 8.15 (bs, 1 H) Melting Point : 100-103C Reference Example 5> Preparation of 5-methyl-3, 4-diphenyl- isoxazole Formula 17> 4g of 1,2-diphenyl-ethanone oxime from Reference Example 1 was introduced into the container, and anhydrous THF 20ml was added to the container under a nitrogen blanket, and the 1,2-diphenyl-ethanone oxime solution was cooled to-78 C. And 2.05 equivalent of n-butyl lithium was slowly added to the solution. Then, the solution was refluxed at the same temperature for 1 hour, warmed up to room temperature, and refluxed one more hour at the room temperature. After the reflux, 1.1 equivalent of anhydrous acetic acid was added thereto, and then stirred at room

temperature for 2 hours. After completing the reaction, 50ml of water was added thereto, and extracted with ethyl acetate to separate an organic layer. The separated organic layer was dried with anhydrous magnesium sulfate, and a solvent was evaporated under reduced pressure to obtain a liquid in oil phase. The liquid was directly dissolved in 50 ml of dichloromethane, and then 3ml of a- concentrated sulfuric acid was added thereto, and then refluxed for 3 hours. After completing the reaction, 100ml of water was added thereto, and extracted with dichloromethane to separate an organic layer. The separated organic layer was dried with anhydrous magnesium sulfate, and a solvent was evaporated under reduced pressure to obtain a liquid in oil phase. The liquid was purified through a column chromatography with a mixture of ethylacetate and normal hexane in the ratio of 1 : 30. As a result, 2. 50g of the compound of the formula 17 (yield: 56%) was obtained as a liquid phase.

Mass (LOW EI) = 235. 11 Reference Example 6> Preparation of 3- (4-bromophenyl)-5- methyl-4-isoxazole <Formula 18>

The reaction was carried out through the same method as Reference Example 5, except employing the compound of Reference Example 2,2g of 1- (4-bromophenyl)-2-phenyl ethanone oxime instead of 1,2-diphenyl-ethanone oxime. As a result, 1.05g of the compound of the formula 18 (yield: 51%) was obtained as a liquid phase.

1H-NMR (400MHz, CDC13) 2. 51 (s, 3 H), 7, 32-7. 38 (m, 5 H), 7. 45-7. 50 (m, 4 H) Reference Example 7> Preparation of 3- (4-methoxyphenyl)-5- methyl-4-phenyl-isoxazole Formula 19> The reaction was carried out through the same method as Reference Example 5, except employing 0. 5g of 1- (4- methoxyphenyl)-2-phenyl ethanone oxime of Reference Example 3, instead of 1,2-diphenyl-ethanone oxime. As a result, 0.26g of the compound of the formula 19 (yield: 48%) was obtained as a liquid phase.

Mass (LOW EI) = 265. 1 Reference Example 8> Preparation of 3- (4-fluorophenyl)-5- methyl-4-phenyl-isoxazole Formula 20>

The reaction was carried out through the same method as Reference Example 5, except employing 1.5g of 1- (4- <BR> fluorophenyl) -2-phenyl ethanone oxime of the compound of Reference Example 4, instead of 1,2-diphenyl-ethanone oxime.

As a result, 0. 99g of the compound of the formula 20 (yield: 60%) was obtained as a liquid phase.

Mass (LOW EI) = 253. 1 Reference Example 9> Preparation of 2-(4-fluorophenyl)-1- (4-methanesulfonylphenyl)-butane-1, 3-dione Formula 21>

2g of 1- (4-fluorophenyl)-propane-2-one, 2. 0g of 4- methanesulfonyl benzoic acid and 1.67g of carbonyl diimidazole was mixed and dissolved in 10ml of dimethylformamide. And then, 0.8g of sodium hydride was

slowly added to the solution, and then refluxed for 2 hours.

After completing the reaction, 100ml of water was added thereto, and then extracted with dichloromethane to separate an organic layer. The separated organic layer was dried with anhydrous magnesium sulfate, and a solvent was evaporated under reduced pressure. As a result, 2.46g of the compound of the formula 21 (yield: 56%) was obtained as a liquid phase.

<Reference Example 10> Preparation of 4- (4-fluorophenyl)-3- (4-methanesulfonylphenyl)-5-methyl-isoxazole Formula 22> 50Omg of 2-(4-fluorophenyl)-1-(4- methanesulfonylphenyl)-butane-1, 3-dione from Reference Example 5 was dissolved in 10ml of ethanol, and then 115 mg of hydroxylamine hydrochloride and 136 mg of sodium acetate were added thereto, and then refluxed for 8 hours. After completing the reaction, 20 ml of water was added thereto, and then extracted with ethyl acetate to separate an organic layer. The organic layer was dried with anhydrous magnesium sulfate, and a solvent was evaporated under reduced pressure to yield a liquid in oil phase. The

liquid was purified through a column chromatography with ethylacetate and normal hexane in the ratio of 1 : 10. As a result, 370 mg of the compound of the formula 22 (yield: 75 %) was obtained as a white solid phase.

1H NMR (400 MHz, Cd13) 2.34 (s, 3 H), 3.00 (s, 3 H), 7.19 (dd, 2H, J = 8.2, 2.2 Hz), 7.7. 25 (dd, 2 H, 8.2, 2.2 Hz), 7.7 (d, 2 H, J = 8.3 Hz), 7.8 (d, 2 H, J = 8.3 Hz) Melting Point = 120-123C Reference Example 11> Preparation of 5-methyl-3,4- diphenyl-isothiazole <Formula 23> 500 mg of 5-methyl-3,4-diphenyl-isoxazole was dissolved in 30 mg of methanol, and then 250 mg of Raney nickel and 300 mg of sodium hydroxide were added to the solution in sequence, and then refluxed under 1 atm of a hydrogen blanket for 6 hours at room temperature. After completing the reaction of the first stage, the remained solid reactant was filtrated and removed, and the solution was distilled under reduced pressure to yield a liquid in oil phase. The liquid was introduced to the reactor, and 10 ml of anhydrous THF, 225 mg of phosphorus pentasulfide and 125 mg of NaHC03 were sequentially added to the reactor

under a nitrogen blanket, and then stirred at room temperature for 12 hours. After that, 330 mg of tetrachloro-1, 4-diquinolon was added thereto, and refluxed for 12 hours. After completing the reaction of the second stage, 20 ml of water was added thereto, and then extracted with ethyl acetate to separate an organic layer. And the organic layer was dried with anhydrous magnesium sulfate and a solvent was evaporated under reduced pressure to obtain a liquid in oil phase. The liquid was purified through a column chromatography with ethylacetate and normal hexane in the ratio of 1 : 10. As a result, 304mg of the compound of the formula 11 (yield: 57 %) was obtained as a yellow liquid phase.

1H NMR (400 MHz, CDC13) 2.43 (s, 3 H), 7.12-7. 15 (m, 2 H), 7.20-7. 25 (m, 4 H), 7.30-7. 35 (m, 4 H) Reference Example 12> Preparation of 3- (4-bromophenyl)-5- methyl-4-phenyl-isothiazole <Formula 24> The reaction was carried out through the same method as the Reference Example 11, except 500 mg of employing 3-

(4-bromophenyl)-5-methyl-4-phenyl-isoxazole instead of 5- methyl-3,4-diphenyl-isoxazole. As a result, 289 mg of the compound of the formula 24 (yield: 55 %) was obtained as a yellow liquid phase.

1H NMR (400 MHz, CDC13) 2.43 (s, 3 H), 7.12-7. 15 (m, 2 H), 7.20-7. 25 (m, 4 H), 7.40-7. 48 (m, 3 H) <Reference Example 13> Preparation of 3- (4-methoxyphenyl)- 5-methyl-4-phenyl-isothiazole <Formula 25> The reaction was carried out through the same method as the Reference Example 11, except employing 400 mg of 3- <BR> (4-methoxyphenyl) -5-methyl-4-phenyl-isoxazole instead of 5- methyl-3,4-diphenyl-isoxazole. As a result, 233 mg of the compound of the formula 25 (yield: 55 %) was obtained as a yellow liquid phase.

IH NMR (400 MHz, CDC13) 2.43 (s, 3 H), 3.90 (s, 3 H), 6.96 (d, 2 H, J = 8.4 Hz), 7.05-7. 10 (m, 1 H), 7.30-7. 38 (m, 4 H), 7.45 (d, 2 H, J = 8.4 Hz) <Reference Example 14> Preparation of 3- (4-fluorophenyl)-5- methyl-4-phenyl)-isothiazole <Formula 26>

The reaction was carried out through the same method as the Reference Example 11, except employing 900 mg of 3- <BR> (4-fluorophenyl) -5-methyl-4-phenyl-isoxazole instead of 5- methyl-3,4-diphenyl-isoxazole. As a result, 570 mg of the compound of the formula 25 (yield: 60 %) was obtained as a yellow liquid phase.

1H NMR (400 MHz, CDC13) 2.43 (s, 3 H), 3.95 (s, 3 H), 7.05-7. 15 (m, 3 H), 7.30-7. 38 (m, 4 H), 7.40 (d, 2 H, J = 8.4 Hz) Example 1> Preparation of 4- (4-fluorophenyl)-3- (4- methanesulfonyl)-5-methyl-isothiazole <Formula 27> 500mg of 4- (4-fluorophenyl)-3- (4- methanesulfonylphenyl)-5-methyl-isoxazole from Reference

Example 10 was dissolved in 30ml of methanol, and 250 mg of Raney nickle and 300 mg of sodium hydroxide were added thereto in sequence, and then stirred under 1 atm of hydrogen blanket for 6 hours at room temperature. After completing the reaction of the first stage, the remained solid reactants were filtrated and removed, and then the solution was distilled under reduced pressure to yield a liquid in oil phase. The liquid was introduced into the reactor, and 10 ml of anhydrous tetrahydrofuran (THF), 225 mg of phosphorus pentasulfide and 125 mg of NaHCO3 were sequentially added to the reactor under a nitrogen blanket, and then stirred at room temperature for 12 hours. After that, 330 mg of 2,3, 5, 6-tetrachloro-1, 4-benzoquinon was added thereto, and refluxed for 12 hours. After completing the reaction of the second stage, 20ml of water was added thereto, and then extracted with ethyl acetate to separate an organic layer. The organic layer was dried with anhydrous magnesium sulfate and a solvent was evaporated under reduced pressure to yield a liquid in oil phase. The liquid was purified through a column chromatography with ethyl acetate and normal hexane in the ratio of 1 : 10. As a result, 235 mg of the compound of the formula 27 (yield: 45%).

1H NMR (400MHz, Cd13) 2.34 (s, 3 H), 3.20 (s, 3 H), 7. 19 (dd, 2H, J= 8.2, 2.2 Hz), 7.25 (dd, 2 H, 8.2, 2.2 Hz), 7.70 (d, 2 H, J = 8.3 Hz), 7.82 (d, 2 H, J = 8.3 Hz) Example 2> Preparation of 4- (5-methyl-3-phenyl- isothiazole-4-yl)-benzenesulfonamide Formula 28>

800 mg of 5-methyl-3,4-diphenyl-isothiazole from Reference Example 11 was introduced to the reactor, and cooled to OC, and 5ml of chlorosulfonic acid was slowly added thereto. The reactants were stirred at the same temperature for 2 hours. After completing the reaction of the first stage, 100 ml of ice water was slowly added thereto, and extracted with 50 ml of dichloromethane. And then, 50 ml of ammonium water was added thereto and stirred drastically for 1 hour at room temperature. After completing the reaction of the second stage, 100 ml of ice water was slowly added thereto, and extracted with 50 ml of dichloromethane to separate an organic layer. The organic layer was dried with anhydrous magnesium sulfate and a solvent was evaporated under reduced pressure. A prepared liquid in oil phase was re-crystallized through a column chromatography with the mixture solution of ethyl acetate and normal hexane. As a result, 631 mg of the compound of the formula 28 (yield: 60 %) was obtained as a yellow solid

phase.

1H NMR (300 MHz, CDCl3) 2.50 (s, 3 H), 7.20-7. 45 (m, 9 H), 7. 78 (d, 2 H, J = 8.3 Hz) Melting Point: 173-175 C Example 3> Preparation of 4- [3- (4-bromophenyl)-5-methyl- isothiazole-4-yl]-benzenesulfonamide Formula 29> The reaction was carried out through the same method as Example 2, except employing 800 mg of 3- (4-bromophenyl)- 5-methyl-4-phenyl isothiazole the compound of Reference Example 12, instead of 5-methyl-3,4-diphenyl-isothiazole.

As a result, 634 mg of the compound of formula 30 (yield: 64 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, DMSO-d6) 2.48 (s, 3 H), 7.30 (d, 2 H, J -8. 5 Hz), 7. 42 (s, 2 H), 7. 53 (d, 2 H, J = 8.5 Hz), 7. 62 (d, 2 H, J = 8.5 Hz), 7. 80 (d, 2 H, J = 8.5 Hz) Melting Point: 217-220C <Example 4> Preparation of 4- [3- (4-methoxyphenyl)-5-methyl- isothiazole-4-yl]-benzenesulfonamide <Formula 30>

The reaction was carried out through the same method as the Example 2, except employing 300 mg of 3- (4- <BR> methoxyphenyl) -5-methyl-4-phenyl isothiazole of the compound of Reference Example 13, instead of 5-methyl-3,4- diphenyl-isothiazole. As a result, 310 mg of the compound of the formula 30 (yield: 74 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, DMSO-d6) 2. 48 (s, 3 H), 3.90 (s, 3 H), 6.94 (d, 2 H, J = 8.4 Hz), 7.42 (s, 2 H), 7.46 (d, 2 H, J = 8.4 Hz), 7.53 (d, 2 H, J = 8.5 Hz), 7.95 (d, 2 H, J = 8.5 Hz) Example 5> Preparation of 4- [3- (4-fluorophenyl)-5-methyl- isothiazole-4-yl]-benzenesulfonamide <Formula 31> The reaction was carried out through the same method as Example 2, except exploiting 900 mg of 3- (4- fluorophenyl) -5-methyl-4-phenyl isothiazole of the compound

of Reference Example 14, instead of 5-methyl-3,4-diphenyl- isothiazole. As a result, 725 mg of the compound of formula 31 (yield: 66 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, DMSO-d6) 2.48 (s, 3 H), 3.80 (s, 3 H), 7.30 (d, 2 H, J= 7.0 Hz), 7.45-7. 60 (m, 6 H), 8. 00 (d, 2 H, J= 7.0 Hz) Example 6> Preparation of 4- (4-methanesulfonylphenyl)-5- methyl-3-phenyl-isothiazole <Formula 32> 700 mg of 5-methyl-3, 4-diphenyl-isothiazole from Reference Example 11 was introduced to the reactor, and cooled to OC, and 5ml of chlorosulfonic acid was slowly added to the reactor. The reactants were stirred at the same temperature for 2 hours. After completing the reaction of the first stage, 100 ml of ice water was slowly added to the reacting product, and extracted with 50 ml of dichloromethane to separate an organic layer. The organic layer was dried with the anhydrous magnesium sulfate and a solvent was evaporated under reduced pressure. The

obtained product was dissolved in l0ml of anhydrous tetrahydrafuran (THF), and 3 ml of hydrazine was added to the solution at OC m, and stirred for 10 minutes. After evaporating THF, the product was dissolved in 10 ml of ethanol, and 1.2 g of sodium acetate and 2.1 g of methyl iodide were added thereto, and then refluxed for 12 hours.

After completing the reaction of the second stage, 100 ml of water was added thereto, and extracted with ethyl acetate to separate an organic layer. The organic layer was dried with anhydrous magnesium sulfate and a solvent was evaporated to separate an organic layer. A liquid in oil phase was re-crystallized with the mixture of ethyl acetate and normal hexane. As a result, 462 mg of the compound of the formula 32 (yield: 50%) was obtained as a yellow solid.

1H NMR (300 MHz, CDC13) 2.50 (s, 3 H), 3.10 (s, 3 H), 7.15-7. 23 (m, 5 H), 7.27 (d, 2 H, J = 8.7 Hz), 7.80 (d, 2 H, J = 8. 7 Hz) Melting Point : 162-165 C Example 7> Preparation of 3- (4-bromophenyl)-4- (4- methanesulfonylphenyl)-5-methyl-isothiazole <Formula 33>

The reaction was carried out through the same method as Example 6, except employing 600mg of 3- (4-bromophenyl)- 5-methyl-4-phenylisothiazole of the compound of Reference Example 12, instead of 5-methyl-3, 4-diphenyl-isothiazole.

As a result, 407 mg of the compound of the formula 33 (yield: 55 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, CDC13) 2.50 (s, 3 H), 3.12 (s, 3 H), 7. 30 (d, 2 H, J= 8.5 Hz), 7.53 (d, 2 H, J = 8.5 Hz), 7.52 (d, 2 H, J = 8.4 Hz), 7. 75 (d, 2 H, J = 8.4 Hz) mp = 200-205C Example 8> Preparation of 3- (4-methoxyphenyl)-4- (4- methanesulfonylphenyl)-5-methyl-isothiazole Formula 34> The reaction was carried out through the same method as Example 6, except employing 600mg of 3- (4-

methoxyphenyl) -5-methyl-4-phenylisothiazole of the compound of Reference Example 13, instead of 5-methyl-3,4-diphenyl- isothiazole. As a result, 387 mg of the compound of the formula 34 (yield: 50 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, CDC13) 2.50 (s, 3 H), 3.12 (s, 3 H), 3.98 (s, 3 H) 7. 00 (d, 2 H, J = 8.9 Hz), 7. 30 (d, 2 H, J = 8.9 Hz), 7. 60 (d, 2 H, J = 8. 6 Hz), 7.95 (d, 2 H, J = 8.6 Hz) Example 9> Preparation of 3- (4-fluorophenyl)-4- (4- methanesulfonyl)-5-methyl-isothiazole Formula 35> The reaction was carried out through the same method as Example 6, except employing 500mg of 3- (4- fluorophenyl)-5-methyl-4-phenylisothiazole of the compound of Reference Example 14, instead of 5-methyl-3,4-diphenyl- isothiazole. As a result, 287 mg of the compound of the formula 35 (yield: 45 %) was obtained as a yellow solid phase.

1H NMR (400 MHz, CDC13) 2.50 (s, 3 H), 3.12 (s, 3 H), 7.20 (d, 2 H, J= 7.0 Hz), 7. 45 (dd, 2 H, J = 7.0, 10.2 Hz), 7. 60 (d, 2 H, J= 8.7 Hz), 8.00 (d, 2 H, J= 8.7 Hz)

<Pharmacologically Experimental Example> The selective inhibition activity against cyclooxygenase-2 (1) Experimental procedure In order to investigate pharmacologically the selective inhibition activity against cyclooxygenase-2 enzyme, the inhibitive effects against cyclooxygenase-1 and cyclooxygenase-2 were measured by two methods as follows. i) Analysis of the inhibitive effects against the cyclooxygenase-1 using U-937 A cultured U-937 (humane lymphoma cell with Deposit No. 21593, obtained from Korean cell line bank) was centrifuged to collect the pellet. Then, the pellet was diluted with lxHBSS (Hanks balanced salt solution) at the concentration of 1 x 106 cells/ml, and lml of them was transferred into each of 12-well plates.

And then, 5 of 1gM detecting solution prepared by diluting in DMSO and 5flt of DMSO vehicle were added thereto and mixed, and the mixture was cultured at 37C in C02 incubator for 15 minutes. Arachidonic acid as a substrate was dissolved in ethanol to prepare a stock solution with a concentration of lOmM, followed by diluting with 1 x HBSS to prepare the solution of lmM. 10 of 1mM Arachidonic acid solution was added to each of the treated wells and the mixture was cultured at 37C in C02 incubator for 30 minutes.

The cell solution of each well was collected in the

centrifuge tube and centrifuged at 4C, for 5 minutes at 10, 000rpm. As PGE2 existed in the supernatant separated from collected cell, the concentration of PGE2 was quantitated by using monoclonal kit from Cayman Chemicals, and the concentration of samples and DMSO vehicle were compared to estimate the inhibition ratio (%) of each compound against cyclooxygenase-1. Ultimately, the inhibition effect against the cyclooxygenase-1 enzyme was obtained from the result. ii) Analysis of the inhibitive effects against the cyclooxygenase-2 using Raw 264.7.

After seeding 2x106 cells of Raw 264.7 cell (obtained from Korean cell line bank, Deposit No. 40071) into each of 12-well plates, the wells were treated with 250 jim aspirin and cultured at 37C in C02 incubator for 2 hours, and then was replaced with new media, treated with each lOnM detecting sample, and cultured for 30 minutes. In addition, the samples were treated with 100 units/ml of interferon y and lOOng/ml of lipopolysaccharide (LPS), and cultured for 18 hours. Then, the media was transferred to other test tubes and PGE 2 was quantitated by using EIA kit (Cayman Chemicals).

(2) Experimental results The % inhibition was calculated as follows, and the results were described in Table 1.

% inhibition = {(PGE2 concentration compensated with

interferon y and LPS-PGE2 concentration compensated with <BR> <BR> analysis sample) / (PGE2 concentration compensated with interferon y and LPS)} x 100 <Table 1> Inhibitory effects of cyclooxygenase (COX) (unit: % inhibition) Examples COX-l (l0pM) COX-2 (30nM) Standard Substance 84.0 65.7 (Celecoxib) 1 29. 8 63. 7 2 35. 5 60. 2 3 38. 8 58. 5 4 79. 5 67. 7 5 77. 8 72. 3 6 56. 4 69. 0 7 45. 7 65. 6 880. 176. 4 9 67. 2 65. 1

(3) Evaluation In vitro experimental results for the inhibition of cyclooxygenase-1 and cyclooxygenase-2 were observed as follows.

Consequently, in case of the compounds of Example 1~9, the ratio of the inhibition % of cyclooxygenase-2 to cyclooxygenase-1 was much higher than the standard substance (Celecoxib). That is to say, it is shown that

the selective inhibition of cyclooxygenase-2 against cyclooxygenase-1 is better than that of any other standard substances.

INDUSTRIAL APPLICABILITY As demonstrated and confirmed above, the novel compound of the present invention is a drug substitute improving side effects of anti-inflammatory drug in conventional non-steroids, and is useful for patients suffering from peptic ulcer, gastritis, partial enteritis, ulcerative colitis, diverticulitis, gastrointestinal haemorrhagia, hypoprothrombinemia and the like. Besides, it is expected to be useful for treating inflammatory diseases such as osteoarthritis, rheumatoid arthritis and the like effectively.

Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention.