The present invention also provides a process for the preparation of the above said novel amino substituted pyrimidinone derivatives of the formula (I) pharmaceutically acceptable salts, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their hydrates, their solvates, their pharmaceutically acceptable salts, and pharmaceutical compositions containing them.

The novel amino substituted pyrimidinone derivatives of the present invention are useful for the treatment of inflammation and immunological diseases. Particularly the compounds of the present invention are useful for the treatment of inflammation and immunological diseases those mediated by cytokines such as TNF-a, IL-1, IL-6, IL-1ß, IL-8 and cyclooxygenase such as COX-2 and COX-3. The compounds of the present invention are also useful in the treatment of rheumatoid arthritis; osteophorosis; multiple myeloma; uveititis; acute and chronic myelogenous leukemia; ischemic heart disease; atherosclerosis; cancer; ischemic-induced cell damage; pancreatic ß cell destruction; osteoarthritis; rheumatoid spondylitis; gouty arthritis; inflammatory bowel disease; adult respiratory distress syndrome (ARDS); psoriasis; Crohn's disease; allergic rhinitis; ulcerative colitis; anaphylaxis; contact dermatitis; asthma; muscle degeneration; cachexia; type I and type II diabetes; bone resorption diseases; ischemia reperfusion injury; atherosclerosis; brain trauma; multiple sclerosis; cerebral malaria; sepsis; septic shock ; toxic shock syndrome; fever, and myalgias due to infection; and diseases mediated by HIV-1; HIV-2; HIV-3 ; cytomegalovirus (CMV); influenza; adenovirus; the herpes viruses (including HSV-1, HSV-2) and herpes zoster viruses.

Background Art It has been reported that Cyclooxygenase enzyme exists in three isoforms, namely, COX-1, COX-2 and COX-3. COX-1 enzyme is essential and primarily responsible for the regulation of gastric fluids whereas COX-2 enzyme is present at the basal levels and is reported to have a major role in the prostaglandin synthesis for inflammatory response.

These prostaglandins are known to cause inflammation in the body. Hence, if the synthesis of these prostaglandins is stopped by way of inhibiting COX-2 enzyme, inflammation and its related disorders can be treated. COX-3 possesses glycosylation-dependent cyclooxygenase activity. Comparison of canine COX-3 activity with murine COX-1 and COX-2 demonstrated that this enzyme is selectively inhibited by analgesic/antipyretic drugs such as acetaminophen, phenacetin, antipyrine, and dipyrone, and is potently inhibited by some nonsteroidal antiinflammatory drugs. Thus, inhibition of COX-3 could represent a primary central mechanism by which these drugs decrease pain and possibly fever. Recent reports show that inhibitors of COX-1 enzyme causes gastric ulcers, where as selective COX-2 and COX-3 enzyme inhibitors are devoid of this function and hence are found to be safe.

The present invention is concerned with treatment of immunological diseases or inflammation, notably such diseases are mediated by cytokines or cyclooxygenase. The principal elements of the immune system are macrophages or antigen-presenting cells, T cells and B cells. The role of other immune cells such as NK cells, basophils, mast cells and dendritic cells are known, but their role in primary immunologic disorders is uncertain.

Macrophages are important mediators of both inflammation and providing the necessary "help"for T cell stimulation and proliferation. Most importantly macrophages make IL-1, IL-12 and TNF-a all of which are potent pro-inflammatory molecules and also provide help for T cells. In addition, activation of macrophages results in the induction of enzymes, such as cyclooxygenase-2 (COX-2) and cyclooxygenase-3 (COX-3), inducible nitric oxide synthase (iNOS) and production of free radicals capable of damaging normal cells. Many factors activate macrophages, including bacterial products, superantigens and interferon gamma (IFN y). It is believed that phosphotyrosine kinases (PTKs) and other undefined cellular kinases are involved in the activation process.

Cytokines are molecules secreted by immune cells that are important in mediating immune responses. Cytokine production may lead to the secretion of other cytokines, altered cellular function, cell division or differentiation. Inflammation is the body's normal

response to injury or infection. However, in inflammatory diseases such as rheumatoid arthritis, pathologic inflammatory processes can lead to morbidity and mortality. The cytokine tumor necrosis factor-alpha (TNF-a) plays a central role in the inflammatory response and has been targeted as a point of intervention in inflammatory disease. TNF-a is a polypeptide hormone released by activated macrophages and other cells. At low concentrations, TNF-a participates in the protective inflammatory response by activating leukocytes and promoting their migration to extravascular sites of inflammation (Moser et al. , J Clin Invest, 83,444-55, 1989). At higher concentrations, TNF-a can act as a potent pyrogen and induce the production of other pro-inflammatory cytokines (Haworth et al., Eur J Immunol, 21,2575-79, 1991; Brennan et al., Lancet, 2,244-7, 1989). TNF-a also stimulates the synthesis of acute-phase proteins. In rheumatoid arthritis, a chronic and progressive inflammatory disease affecting about 1% of the adult U. S. population, TNF-a mediates the cytokine cascade that leads to joint damage and destruction (Arend et al., Arthritis Rheum, 38,151-60, 1995). Inhibitors of TNF-a, including soluble TNF receptors (etanercept) (Goldenberg, Clin Ther, 21,75-87, 1999) and anti-TNF-a antibody (infliximab) (Luong et al., Ann Pharmacother, 34,743-60, 2000), have recently been approved by the U. S. Food and Drug Administration (FDA) as agents for the treatment of rheumatoid arthritis.

Elevated levels of TNF-a have also been implicated in many other disorders and disease conditions, including cachexia, septic shock syndrome, osteoarthritis, inflammatory bowel disease such as Crohn's disease and ulcerative colitis etc.

Elevated levels of TNF-a and/or IL-1 over basal levels have been implicated in mediating or exacerbating a number of disease states including rheumatoid arthritis; osteoporosis; multiple myeloma; uveititis; acute and chronic myelogenous leukemia ; pancreatic 3 cell destruction; osteoarthritis ; rheumatoid spondylitis; gouty arthritis; inflammatory bowel disease; adult respiratory distress syndrome (ARDS); psoriasis; Crohn's disease; allergic rhinitis; ulcerative colitis; anaphylaxis; contact dermatitis ; asthma ; muscle degeneration; cachexia; type I and type II diabetes; bone resorption diseases; ischemia reperfusion injury; atherosclerosis; brain trauma; multiple sclerosis; cerebral malaria; sepsis; septic shock; toxic shock syndrome; fever, and myalgias due to infection.

HIV-1, HIV-2, HIV-3, cytomegalovirus (CMV), influenza, adenovirus, the herpes viruses (including HSV-1, HSV-2), and herpes zoster are also exacerbated by TNF-a.

It can be seen that inhibitors of TNF-a are potentially useful in the treatment of a wide variety of diseases. Compounds that inhibit TNF-a have been described in several patents.

Excessive production of IL-6 is implicated in several disease states, it is highly desirable to develop compounds that inhibit IL-6 secretion. Compounds that inhibit IL-6 have been described in U. S. Pat. Nos. 6,004, 813; 5,527, 546 and 5,166, 137.

The cytokine IL-1 (3 also participates in the inflammatory response. It stimulates thymocyte proliferation, fibroblast growth factor activity, and the release of prostaglandin from synovial cells. Elevated or unregulated levels of the cytokine IL-1p have been associated with a number of inflammatory diseases and other disease states, including but not limited to adult respiratory distress syndrome, allergy, Alzheimer's disease etc. Since overproduction of IL-1 (3 is associated with numerous disease conditions, it is desirable to develop compounds that inhibit the production or activity of IL-1.

In rheumatoid arthritis models in animals, multiple intra-articular injections of IL-1 have led to an acute and destructive form of arthritis (Chandrasekhar et al. , Clinical Immunol Immunopathol. 55,382, 1990). In studies using cultured rheumatoid synovial cells, IL-1 is a more potent inducer of stromelysin than TNF-a. (Firestein, Am. J. Pathol.

140,1309, 1992). At sites of local injection, neutrophil, lymphocyte, and monocyte emigration has been observed. The emigration is attributed to the induction of chemokines (e. g. , IL-8), and the up-regulation of adhesion molecules (Dinarello, Eur. Cytokine Netw.

5,517-531, 1994).

In rheumatoid arthritis, both IL-1 and TNF-a induce synoviocytes and chondrocytes to produce collagenase and neutral proteases, which leads to tissue destruction within the arthritic joints. In a model of arthritis (collagen-induced arthritis (CIA) in rats and mice) intra-articular administration of TNF-a either prior to or after the induction of CIA led to an accelerated onset of arthritis and a more severe course of the disease (Brahn et al., Lymphokine Cytokine Res. 11,253, 1992; and Cooper, Clin. Exp.

Immunol. 898,244, 1992).

IL-8 has been implicated in exacerbating and/or causing many disease states in which massive neutrophil in filtration into sites of inlammation or injury (e. g. , ischemia) is mediated chemotactic nature of IL-8, including, but not limited to, the following: asthma, inflammatory bowl disease, psoriasis, adult respiratory distress syndrome, cardiac and renal reperfusion injury, thrombosis and glomerulonephritis. In addition to the chemotaxis

effect on neutrophils, IL-8 has also has ability to activate neutrophils. Thus, reduction in IL-8 levels may lead to diminished neutrophil infiltration.

Few prior art reference which disclose the closest pyrimidine compounds are given here: i) US patent Nos. 6,420, 385 and 6,410, 729 disclose novel compounds of formula (IIa) represents X is O, S or NR ; ; represents--Y or--Z--Y, and R4 represents--Z--Y ; provided that R4 is other than a substituted-aryl, (substituted-aryl) methyl or (substituted-aryl) ethyl radical; wherein each Z is independently optionally substituted alkyl, alkenyl, alkynyl, heterocyclyl, aryl or heteroaryl; Y is independently a hydrogen; halo, cyano, nitro, etc., R 5 is independently a hydrogen, optionally substituted alkyl, alkenyl, alkynyl etc., Rll and R12 are each independently represent optionally substituted aryl or heteroaryl.

An example of these compounds is shown in formula (IIb) ii) DE 2142317 discloses hypnotic uracil derivatives of formula (IIc)

wherein Ru ils H, alkyl, alkenyl, dialkylaminoalkyl, or aralkyl ; R2 is H, alkyl, aryl, or halogen ; R3 is alkyl, alkenyl, cycloalkyl, aralkyl, aralkenyl, or aryl, R4 is alkyl, alkenyl, cycloalkyl, aralkyl, aryl, etc.

An example of these compounds is shown in formula (IId) iii) US patent Nos. 5,726, 124 and 5,300, 477 discloses novel herbicidal compounds of formula (IIe) R2 is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaromatic group (e. g. a heteroaromatic ring structure having four to five carbon atoms and one heteroatom selected from the group consisting of nitrogen, sulfur and oxygen); R3 is an alkyl, haloalkyl, polyhaloalkyl, haloalkenyl, polyhaloalkenyl, alkenyl, alkynyl, <BR> <BR> <BR> haloalkynyl, polyhaloalkynyl, alkenynyl, alkoxyalkyl, dialkoxyalkyl, haloalkoxyalkyl, oxoalkyl, trimethylsilylallcynyl, cyanoalkyl or aryl group; Rs is a hydrogen, halo, acyl, alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkoxyalkyl, alkoxyimino, alkoxycarbonylalkyl, dialkoxyalkyl, formyl, haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, hydroxyallcyl, hydroxyimino, polyhaloallcyl, polyhaloalkenyl, polyhaloalkynyl, polyhaloalkoxy, trimethylsilylalkynyl, alkoxyalkoxy, aminocarbonylalkyl, alkylaminocarbonylalkyl, dialkylaminocarbonylalkyl, cyanoalkyl, hydroxy or cyano group; and R6 is a hydrogen, halo, alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkoxyalkyl, alkoxycarbonyl, alkoxycarbonylalkyl, haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, haloalkylthio, polyhaloalkyl, polyhaloalkenyl, polyhaloalkynyl, polyhaloalkoxy, polyhaloalkylthio, cycloalkyl, aryl, aryloxy, heterocyclyl, aralkyl, alkylamino, dialkylamino, dialkylaminocarbonyl, or cyano group; and X is oxygen or sulfur.

An example of these compounds is shown in formula (IIf)

Objective of the Invention We have focused our research to identify selective COX-2 and COX-3 inhibitors which are devoid of any side effects, normally associated with anti-inflammatory agents.

Our sustained efforts have resulted in novel amino substituted pyrimidinone derivatives of the formula (I). The derivatives may be useful in the treatment of inflammation and immunological diseases. Particularly the compound of the present invention are useful for the treatment of inflammation and immunological diseases those mediated by cytokines such as TNF-a, IL-1, IL-6, IL-10, IL-8 and cyclooxygenase such as COX-2 and COX-3.

The compounds of the present invention are also useful in the treatment of rheumatoid arthritis ; osteoporosis; multiple myeloma; uveititis; acute and chronic myelogenous leukemia ; ischemic heart disease; atherosclerosis ; cancer; ischemic-induced cell damage; pancreatic 8 cell destruction; osteoarthritis; rheumatoid spondylitis; gouty arthritis; inflammatory bowel disease; adult respiratory distress syndrome (ARDS); psoriasis; Crohn's disease; allergic rhinitis; ulcerative colitis; anaphylaxis; contact dermatitis; asthma; muscle degeneration; cachexia; type I and type II diabetes; bone resorption diseases; ischemia reperfusion injury; atherosclerosis; brain trauma; multiple sclerosis; cerebral malaria; sepsis; septic shock; toxic shock syndrome; fever, and myalgias due to infection; and diseases mediated by HIV-1 ; HIV-2; HIV-3; cytomegalovirus (CMV); influenza; adenovirus; the herpes viruses (including HSV-1, HSV-2) and herpes zoster viruses.

Summary of the Invention The present invention relates to novel amino substituted pyrimidinone derivatives of the formula (I)

their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, and their pharmaceutically acceptable salts, wherein X represents oxygen, sulfur or NR, wherein R represents hydrogen, hydroxyl, acyl, alkyl, alkoxy, aryl, amino, hydroxylamino, alkylamino, arylamino, acylamino, alkoxyamino group; the rings represented by A and B are selected from aryl or heteroaryl; Y represents a bond or NR8, wherein R8 represents hydrogen, alkyl and the like; the rings represented by A and B are selected from aryl or heteroaryl; R1 and R3 may be same or different and independently represent hydrogen, SR6, wherein R6 represents alkyl or aryl; S (O) pR7, wherein R represents alkyl, amino or aryl group and p represents an integer of 1 or 2; R2 and R4 may be same or different and independently represent hydrogen, halogen, hydroxyl, nitro, cyano, azido, nitroso, amino, formyl, alkyl, haloalkyl, acyl, alkoxy, monoalkylamino, dialkylamino, acylamino, alkoxycarbonyl, alkylsulfonyl, alkylsulfinyl, alkylsulfanyl, sulfamoyl, alkoxyalkyl groups or carboxylic acids or its derivatives; R 5 represents hydrogen, halogen, hydroxyl, formyl, cyano, nitroso, nitro, amino, alkyl, acyl, monoalkylamino, dialkylamino, arylamino, acylamino, alkoxyalkyl or COR9, wherein R9 represents hydroxyl, amino, halogen, alkoxy, aryloxy, monoalkylamino, dialkylamino, arylamino groups; m is an integer and is in the range of 0 to 2; n is an integer and is in the range of 0 to 2.

Detailed Description of the Invention Suitable ring systems represented by A and B are selected from phenyl, naphthyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, piperidinyl, piperazinyl, pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyrimidinyl, benzopyranyl, benzofuranyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzopyrolyl, benzoxadiazolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, benzothienyl, benzofuranyl, indolyl and the like.

Suitable groups represented by R1 and R3 are selected from hydrogen, SR6, S (O) pR.

Suitable groups represented by R6 are selected from linear or branched (CI-C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl and the like ; aryl group such as phenyl or naphthyl.

Suitable groups represented by R7 are selected from amino, linear or branched (Cl- C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n- pentyl, isopentyl, hexyl and the like; aryl group such as phenyl or naphthyl.

Suitable groups represented by R2 and R4 are selected from hydrogen, halogen atom such as fluorine, chlorine, bromine, iodine; hydroxyl, nitro, cyano, azido, nitroso, amino, fonnyl, linear or branched (Cl-C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl and the like; haloalkyl such as chloromethyl, chloroethyl, trifluoromethyl, trifluoroethyl, dichloromethyl, dichloroethyl and the like ; acyl group such as-C (=O) CH3, -C (=O) C2Hs,-C (=O) C3H7,-C (=O) C6HI3,- C (=S) CH3, -C (=S) C2Hs,-C (=S) C3H7,-C (=S) C6HI3, benzoyl; linear or branched (CI-C6) alkoxy group, such as methoxy, ethoxy, n-propoxy, isopropoxy and the like ; monoalkylamino group such as-NHCH3,-NHC2H5,-NHC3H7,-NHC6H13, and the like ; dialkylamino group such as-N (CH3) 2,-NCH3 (C2H5),-N (C2H5) 2 and the like ; acylamino <BR> <BR> <BR> <BR> group such as-NHC (=O) CH3, -NHC (=O) C2H5,-NHC (=O) C3H7-NHC (=O) C6HI3, and the like ; alkoxycarbonyl group such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl and the like; alkylsulfonyl group such as methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, iso-propylsulfonyl and the like ; alkylsulfinyl group such as methylsulfinyl, ethylsulfinyl, n-propylsulfinyl, iso-propylsulfinyl and the like ; alkylthio group such as methylthio, ethylthio, n-propylthio, iso-propylthio and the like ; alkoxyalkyl group such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl and the like ; carboxylic acid or its derivatives such as esters, amides and acid halides.

Suitable groups represented by R are selected from hydrogen, halogen atom such as chlorine, fluorine, bromine or iodine; hydroxyl, formyl, cyano, nitroso, nitro, amino, linear or branched (Cl-C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl and the like ; haloalkyl such as chloromethyl, chloroethyl, trifluoromethyl, trifluoroethyl, dichloromethyl, dichloroethyl and the like ; acyl group such as-C (=O) CH3, -C (=O) C2H5,-C (=O) C3H7,-C (=O) C6HI3,-C (=O) CF3, benzoyl and the like ; monoalkylamino group such as-NHCH3,-NHC2Hs,-NHC3H7-NHC6HI3, and the like; dialkylamino group such as-N (CH3) 2,-NCH3 (C2Hs),-N (C2H5) 2 and the like ; acylamino group such as-NHC (=O) CH3, -NHC (=O) C2Hs,-NHC (=O) C3H7,- NHC (=O) C6Hl3, and the like; alkoxyalkyl groups such as methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl and the like; arylamino such as phenyl amino, naphthyl amino and the like or COR9 Suitable groups represented by R8 are selected from hydrogen, amino, linear or branched (CI-C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl and the like.

Suitable groups represented by R9 are selected from hydroxyl, amino, halogen, linear or branched (Cl-C6) alkoxy group, such as methoxy, ethoxy, n-propoxy, isopropoxy and the like; monoalkylamino group such as NHCH3, NHC2Hs, NHC3H7, NHC6H13, and the like, which may be substituted; dialkylamino group such as N (CH3) 2, NCH3 (C2Hs), N (C2Hs) 2 and the like ; aryloxy group such as phenoxy, napthoxy and the like; arylamino such as phenyl amino, naphthyl amino and the like.

Suitable groups represented by R are selected from hydrogen, hydroxyl, amino, hydroxylamino, linear or branched (Cl-C6) alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, hexyl and the like; linear or branched (Cl-C6) alkoxy group, such as methoxy, ethoxy, n-propoxy, isopropoxy and the like; aryl group such as phenyl, naphthyl and the like; acyl group such as-C (=O) CH3, - <BR> <BR> <BR> <BR> C (=O) C2Hs,-C (=O) C3H7,-C (=O) C6Hl3,-C (=S) CH3,-C (=S) C2Hs,-C (=S) C3H7 C (=S) C6Hl3, benzoyl; aryl group such as phenyl or naphthyl ; alkylamino group such as NHCH3, NHC2H5, NHC3H7, NHC6H13, N (CH3) 2, NCH3 (C2Hs), N (C2Hs) 2 and the like ; acylamino group such as NHC (=O) CH3, NHC (=O) C2Hs, NHC (=O) C3H7, NHC (=O) C6H13, and the like ; arylamino such as phenyl amino, naphthyl amino and the like ; alkoxyamino such as methoxyamino, ethoxyamino, propoxy amino and the like. m and n are integers ranging from 0-2.

Pharmaceutically acceptable salts of the present invention include alkali metal salts like Li, Na, and K salts, alkaline earth metal salts like Ca and Mg salts, salts of organic bases such as diethanolamine, a-phenylethylamine, benzylamine, piperidine, morpholine, pyridine, hydroxyethylpyrrolidine, hydroxyethylpiperidine, guanidine, choline and the like, ammonium or substituted ammonium salts, aluminum salts. Salts also include amino acid salts such as glycine, alanine, cystine, cysteine, lysine, arginine, phenylalanine etc. Salts may include acid addition salts where appropriate which are, sulphates, nitrates, phosphates, perchlorates, borates, hydrohalides, acetates, tartrates, maleates, citrates, succinates, palmoates, methanesulphonates, tosylates, benzoates, salicylates, hydroxynaphthoates, benzenesulfonates, ascorbates, glycerophosphates, ketoglutarates and the like. Pharmaceutically acceptable solvates may be hydrates or comprising other solvents of crystallization such as alcohols.

Representative compounds according to the present invention include: 6-Amino-1-phenyl-2-phenylamino-1 H-pyrimidin-4-one ; 6-Amino-l- (4-methylphenyl)- 2-phenylamino-lH-pyrimidin-4-one ;

6-Amino-1- (4-methoxyphenyl)-2-phenylamino-1 H-pyrimidin-4-one ; 6-Amino-1- (4-ethoxyphenyl)-2-phenylamino-1 H-pyrimidin-4-one ; 6-Amino-1- (4-chlorophenyl)-2- phenylamino-lH-pyrimidin-4-one ; 6-Amino-1-(4-bromlophenyl)-2- phenylamio-1H-pyrimidin-4-one ; 6-Amino-1- (4-methylsulfonyl-phenyl)-2- phenylamino-1H-pyrimidin-4-one ; 6-Amino-2- (4-methyl-phenylamino)-1-phenyl-lH-pyrimidin-4-one ; 6-Amino-2-(4-methoxy-phenoxylamino)-1-phenyl-1H-pyrimidin-4- one; 6-Amino-2- (4-ethoxy-phenylamino)-l-phenyl-lH-pyrimidin-4-one ; 6-Amino-2- (4-methylthio-phenylamino)-l-phenyl-lH-pyrimidin-4-one ; 6-Amino-2- (4-chloro-phenylamino)-1-phenyl-lH-pyrimidin-4-one ; 6-Amino-2- (4-fluoro-phenylamino)-l-phenyl-lH-pyrimidin-4-one ; 6-Amino-2- (4-methylthio-phenylamino)-l- (4-methylthiophenyl)-lH-pyrimidin-4-one ; 6-Amino-1-(4-methylphenyl)-2-(4-methylthio-phenylamino)-1 H-pyrimidin-4-one ; 6-Amino-2- (4-methylsulfonyl-phenylamino)-1-phenyl-1 H-pyrimidin-4-one ; 6-Amino-2-(4-methylthio-phenylamino)-1-(4-methylphenyl)-lH-p yrimidin-4-one ; 4- (6-Amino-4-oxo-1-phenyl-1, 4-dihydro-pyrimidin-2-ylamino) -benzenesulfonamide; 4- (6-Amino-4-oxo-1- (4-methyl-phenyl)-1, 4-dihydro-pyrimidin-2-ylamino) - benzenesulfonamide; 6-Amino-2-phenylamino-1- (pyridin-2-yl)-1 H-pyrimidin-4-one ; 6-Amino-2- (4-methoxy-phenylamino)-l- (pyridin-2-yl)-lH-pyrimidin-4-one ; 6-Amino-2- (4-methyltliio-phenylamino)-1- (pyridin-2-yl)-1 H-pyrimidin-4-one ; 6-Amino-2- (4-ethoxy-phenylamino)-1- (pyridin-2-yl)-lH-pyrimidin-4-one ; 6-Amino-1- (4-methoxypyridin-2-yl)-2-phenylamino-1 H-pyrimidin-4-one ; 6-Amino-1- (4-ethoxypyridin-2-yl)-2-phenylamino-1 H-pyrimidin-4-one ; 6-Amino-2-phenylamino-1-(4-chloropyridin-2-yl)-lH-pyrimidin- 4-one ; 6-Amino-2- phenylamino1-(4-bromopyridin-2-yl)-1H-pyrimidin-4-one; According to yet another embodiment of the present invention, there is provided a process for the preparation of novel amino substituted pyrimidinone derivatives of the formula (I) wherein Y represents NR8, where R8 and all other symbols are as defined above, which comprises, reacting compound of formula (Ia) where all symbols are as defined above with compound of formula (Ib)

where all symbols are as defined above.

The reaction of compound of formula (Ia) with (Ib) to produce compound of formula (I) may be carried out in the presence of solvents such as toluene, xylene, tetrahydrofuran, dioxane, chloroform, dichloromethane, dichloroethane, o- dichlorobenzene, acetone, pyridine, ethyl acetate, acetonitrile, N, N-dimethylformamide, dimethylsulfoxide, diphenylether, ethanol, methanol, isopropylalcohol, tert-butylalchol, acetic acid, propionic acid and the like or a mixture thereof or by neat reaction. The reaction may be carried out by using phase transfer catalysts viz. triethylbenzylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium hydrogensulphate, tricaprylylmethylammonium chloride (aliquat 336) and the like. The reaction may be carried out at a temperature in the range of 50 °C to reflux temperature for period in the range of 2 to 36 h.

According to yet another embodiment of the present invention there is provided a process for the conversion of novel amino substituted pyrimidinone derivatives of the formula (1) wherein any of the groups R'or W represent SR6, wherein R6 represents alkyl or aryl to novel amino substituted pyrimidinone derivatives of the formula (I) wherein any of the groups Rl or R3 represent S (O) pR7, where p represents 1 or 2 and R7 represents alkyl or aryl; by using suitable oxidizing agent. The oxidizing agent may be selected from potassium peroxymonosulfate (Oxone), hydrogen peroxide, tert-butylperoxide, Jones reagent, peracid [e. g peracetic acid, perbenzoic acid, m-chloroperbenzoic acid etc], chromic acid, potassium pennanganate, alkali metal periodate [e. g sodium periodate, etc], magnesium mono peroxypthalate, osmium tetroxide/N-methylmorpholine-N-oxide, sodium tungstate, and the like. The oxidation is usually carried out in a solvent which does

not adversely influence the reaction such as acetic acid, dichloromethane, acetone, ethyl acetate, chloroform, water, an alcohol [eg. methanol, ethanol, etc. ], a mixture thereof or the like. The reaction temperature is usually carried out under cooling to refluxing conditions.

According to yet another embodiment of the present invention there is provided a process for the conversion of novel amino substituted pyrimidinone derivatives of the formula (I) wherein R'or W represent S (O) pR7, where p is 1 or 2, R represents alkyl or aryl may be converted to novel amino substituted pyrimidinone derivatives of the formula (1) wherein R'or W represent S (O) pR7, where p is 1 or 2, R7 represents amino by using the procedure described in the literature (Huang et. al. Tetrahedron Lett. 39,7201, 1994).

In yet another embodiment of the present invention, there is provided a process for the preparation of novel pyrimidinedione derivatives of the formula (I) wherein either of R'or W represent S (O) pR8, wherein R8 represents amino group and p represents an integer of 1 or 2 and all other symbols are as defined earlier, which comprises reacting compound of formula (Ic) wherein all symbols are as defined earlier wherein either of Rl or R3 represents hydrogen with chlorosulfonic acid and ammonia.

The reaction of compound of formula (Ic) with chlorosulfonic acid and ammonia may be carried out in the presence of solvents such as acetic acid, dichloromethane, acetone, tetrahydrofuran, dioxane, ethyl acetate, chloroform, water, an alcohol and the like or a mixture thereof. The reaction may be carried out at a temperature in the range of 50 °C to reflux temperature for period in the range of 2 to 12 h.

In yet another embodiment of the present invention, there is provided a novel intermediate of formula (Ia)

their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, and their pharmaceutically acceptable salts, wherein X represents oxygen, sulfur or NR, wherein R represents hydrogen, hydroxyl, amino, acyl, alkyl, alkoxy, aryl group; the ring represented by A is selected from aryl or heteroaryl; Ri represents hydrogen, SR6, wherein R6 represents alkyl or aryl; S (O) pR7, wherein R represents alkyl, amino or aryl group and p represents an integer of 1 or 2; R represents hydrogen, halogen, hydroxyl, nitro, cyano, azido, nitroso, amino, formyl, alkyl, haloalkyl, acyl, alkoxy, monoalkylamino, dialkylamino, acylamino, alkoxycarbonyl, alkylsulfonyl, alkylsulfinyl, alkylsulfanyl, sulfamoyl, alkoxyallcyl groups or carboxylic acids or its derivatives; R 5 represents hydrogen, halogen, hydroxyl, formyl, cyano, nitroso, nitro, amino, alkyl, acyl, monoalkylamino, dialkylamino, arylamino, acylamino, alkoxyalkyl or CoR9, wherein R9 represents hydroxyl, amino, halogen, alkoxy, aryloxy, monoalkylamino, dialkylamino, arylamino groups; m is an integer and is in the range of 0 to 2.

In yet another embodiment of the present invention, the compounds of formula (Ia) are prepared by methylating the compound of formula (Ia-1) where all symbols are as defined above.

The methylation of compound of formula (Ia-1) to produce compound of formula (Ia) may be carried out by treating with methylating agent like methyliodide, dimethylsulphate and diazomethane etc. , in the presence of base such as sodium hydroxide, potassium hydroxide, sodium methoxide, sodium hydride, potassium t-butoxide, calcium hydroxide, magnesium hydroxide and the like, in solvents like ether, tetrahydrofuran, methanol, t-butanol, dioxane, isopropanol, ethanol, water and the like or mixture thereof.

It is appreciated that in any of the above-mentioned reactions, any reactive group in the substrate molecule may be protected according to conventional chemical practice.

Suitable protecting groups in any of the above-mentioned reactions are those used conventionally in the art. The methods of formation and removal of such protecting groups are those conventional methods appropriate to the molecule being protected.

The pharmaceutically acceptable salts are prepared by reacting the compound of formula (I) with 1 to 4 equivalents of a base such as sodium hydroxide, sodium methoxide, sodium hydride, potassium t-butoxide, calcium hydroxide, magnesium hydroxide and the like, in solvents like ether, tetrahydrofuran, methanol, t-butanol, dioxane, isopropanol, ethanol etc. Mixture of solvents may be used. Organic bases such as diethanolamine, a- phenylethylamine, benzylamine, piperidine, morpholine, pyridine, hydroxyethylpyrrolidine, hydroxyethylpiperidine, guanidine, choline and the like, ammonium or substituted ammonium salts, aluminum salts. Amino acid such as glycine, alanine, cystine, cystine, lysine, arginine, phenylalanine, etc may be used for the preparation of amino acid salts. Alternatively, acid addition salts wherever applicable are prepared by the treatment with acids such as hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, phosphoric acid, p-toluenesulphonic acid, methanesulfonic acid, acetic acid, citric acid, maleic acid, salicylic acid, hydroxynaphthoic acid, ascorbic acid, palmitic acid, succinic acid, benzoic acid, benzenesulfonic acid, tartaric acid and in solvents like ethyl acetate, ether, alcohols, acetone, tetrahydrofuran, dioxane etc. Mixture of solvents may also be used.

The stereoisomers of the compounds forming part of this invention may be prepared by using reactants in their single enantiomeric form in the process wherever possible or by conducting the reaction in the presence of reagents or catalysts in their single enantiomer form or by resolving the mixture of stereoisomers by conventional methods. Some of the preferred methods include use of microbial resolution, resolving the diastereomeric salts formed with chiral acids such as mandelic acid, camphorsulfonic acid, tartaric acid, lactic acid, and the like wherever applicable or chiral bases such as brucine, cinchona alkaloid and their derivatives and the like. Commonly used methods are compiled by Jaques et al in"Enantiomers, Racemates and Resolution" (Wiley Interscience, 1981). More specifically the compound of formula (I) may be converted to a 1: 1 mixture of diastereomeric amides by treating with chiral amines, aminoacids, aminoalcohols derived from aminoacids; conventional reaction conditions may be employed to convert acid into an amide; the diastereomers may be separated either by fractional crystallization or chromatography and the stereoisomers of compound of formula (I) may be prepared by hydrolysing the pure diastereomeric amide.

Various polymorphs of compound of general formula (I) forming part of this invention may be prepared by crystallization of compound of formula (I) under different

conditions. For example, using different solvents commonly used or their mixtures for recrystallization; crystallizations at different temperatures; various modes of cooling, ranging from very fast to very slow cooling during crystallizations. Polymorphs may also be obtained by heating or melting the compound followed by gradual or fast cooling. The presence of polymorphs may be determined by solid probe NMR spectroscopy, IR spectroscopy, differential scanning calorimetry, powder X-ray diffraction or such other techniques.

Pharmaceutically acceptable solvates of the compounds of formula (I) forming part of this invention may be prepared by conventional methods such as dissolving the compounds of formula (I) in solvents such as water, methanol, ethanol, mixture of solvents such as acetone: water, dioxane: water, N, N-dimethylformamide : water and the like, preferably water and recrystallizing by using different crystallization techniques.

The present invention provides a pharmaceutical composition, containing the compounds of the general formula (I) as defined above, their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable hydrates and solvates in combination with the usual pharmaceutically employed carriers, diluents and the like, useful for the treatment of arthritis, pain, fever, psoriasis, allergic diseases, asthma, inflammatory bowel syndrome, gastro-intestinal ulcers, cardiovascular disorders including ischemic heart disease, atherosclerosis, cancer, ischemic-induced cell damage, particularly brain damage caused by stroke, other pathological disorders associated with free radicals. The pharmaceutical composition of the present invention are effective in the treatment of inflammation and immunological diseases, particularly those mediated by cytokines such as TNF-a, IL-1, IL-6, IL-8 and cyclooxygenase such as COX-2 and COX- 3.

The pharmaceutical composition may be in the forms normally employed, such as tablets, capsules, powders, syrups, solutions, aerosols, suspensions and the like, may contain flavoring agents, sweeteners etc. , in suitable solid or liquid carriers or diluents, or in suitable sterile media to form injectable solutions or suspensions. Such compositions typically contain from 1 to 20 %, preferably 1 to 10 % by weight of active compound, the remainder of the composition being pharmaceutically acceptable carriers, diluents or solvents.

The present invention is provided by the examples given below, which are provided by way of illustration only and should not be considered to limit the scope of the invention.

Preparation 1 Synthesis of 6-amino-1- (4-ethoxyphenyl)-2-thiouracil

Dry hydrogen chloride gas was passed through a mixture of ethyl cyanoacetate (17.3g, 153mmol) and 4-ethoxyphenylthiourea (lOg, 51mmol) in dioxane (60ml) for 20 hours at 0 - 5 °C. The reaction mixture was refluxed for 6 hours, poured onto ice-water mixture and neutralized with saturated sodium bicarbonate solution. The precipitate thus separated was filtered, washed with water and dried in vacuum to yield the title compound (9.32g, 69.5%, purity 94.1% by HPLC) mp 222-225 °C. lH-NMR (DMSO-d6): 5 1.34-1. 37 (t, 3H), 4.04-4. 09 (q, 2H), 4.93 (s, 1H), 6.2 (bs, 2H, D20 exchangeable), 7. 01-7. 03 (d, 2H), 7.15 - 7. 17 (d, 2H), 11.92 (s, 1H, D20 exchangeable). MS m/z : 264.1 (M.

Preparation 2 Synthesis of 6-amino-2-methylthio-1-phenyl-lH-pyrimidin-4-one 6-Amino-1-phenyl-2-thiouracil (5. 5g. 25mmol) (synthesized according to the procedure given in C. J. Shishoo et a/., Indian J. Chem. , 35B, pp 662,1996) was added to the stirred potassium hydroxide (1N, 50ml) solution and filtered. Methyl iodide (6.26g, 44mmol) was added to the vigorous stirred filtrate at 20 °C and stirring was continued at room temperature for 2 hours. The reaction mixture was poured onto ice-water, separated solid was filtered, washed with water and dried to furnish the title compound (4.80g, 82. 1%) mp 213-216 °C. lH-NMR (CDC13) : 8 2.40 (s, 3H), 4.93 (bs, 2H, D20 exchangeable), 5.38 (s, 1H), 7.33-7. 35 (m, 2H), 7.59-7. 60 (s, 3H). MS m/z: 234.1 (M+).

Preparation 3 Synthesis of 6-amino-2-methylthio-1- (4-methylphenyl)-lH-pyrimidin-4-one

The title compound was prepared from 6-amino-l- (4-methylphenyl)-2-thiouracil (7g, 30mmol) (synthesized according to the procedure given in C. J. Shishoo et al., Indian J.

Chem. , 35B, pp 662,1996) by following the procedure described in preparation 2, (6. 0g, 80.9%) mpl30-132 °C. MS m/z: 248.2 (M+).

Preparation 4 Synthesis of 6-amino-2-methylthio-1-(4-methoxyphenyl)-lH-pyrimidin-4-one

The title compound was prepared from 6-amino-1-(4-methoxyphenyl)-2-thiouracil (lOg, 40mmol) (synthesized according to the procedure given in C. J. Shishoo et al., Indian J.

Chem. , 35B, pp 662,1996) by following the procedure described in preparation 2, (9. 64g, 91.3%, purity 99% by HPLC) mp182 - 186 °C. lH-NMR (DMSO-d6) : 8 2.25 (s, 3H), 3. 83 (s, 3H), 4.96 (s, 1H), 5.94 (s, 2H, D20 exchangeable), 7.09-7. 11 (d, 2H), 7.33-7. 35 (d, 2H). MS m/z : 264.1 (M+).

Preparation 5 Synthesis of 6-amino-2-methylthio-1-(4-ethoxyphenyl)-1H-pyrimidin-4-one

The title compound was prepared from 6-amino-l- (4-ethoxyphenyl)-2-thiouracil (8g, 30. 4mmol) (obtained in preparation 1) according to the procedure described in preparation 2, (6. 88g, 81.7%, purity 90.8% by HPLC) mp 177-181 °C. lH-NMR (CDC13) : 8 1.45- 1.49 (t, 3H), 2.42 (s, 3H), 4.10-4. 12 (q, 2H), 5.31 (s, 1H), 7.05-7. 07 (m, 2H), 7.23- 7.25 (m, 2H). MS m/z: 278. 1 (M+).

Preparation 6 Synthesis of 6-amino-2-methylthio-1-(4-chlorophenyl)-lH-pyrimidin-4-one The title compound was prepared by following the procedure described in preparation 2 from 6-amino-l- (4-chlorophenyl)-2-thiouracil (8g, 31. 5mmol) (synthesized according to the procedure given in C. J. Shishoo et al., Indian J. Chem., 35B, pp 662,1996) (7.34g, 86.9%), mp 80-182 °C. 1H-NMR (DMSO-d6) : b 2.27 (s, 3H), 4.96 (s, 1H), 6.09 (s, 2H), 7.50-7. 52 (d, 2H), 7.64-7. 66 (d, 2H). MS m/z : 268.1 (M+).

Preparation 7 Synthesis of 6-amino-2-methylthio-1-(4-bromophenyl)-lH-pyrimidin-4-one The title compound was prepared by following the procedure described in preparation 2 from 6-amino-1- (4-bromophenyl)-2-thiouracil (lg, 3.35mmol) (synthesized according to the procedure given in C. J. Shishoo et al., Indian J. Chem. , 35B, pp 662,1996) (0. 55g, 52.5%), mp 138-140 °C. MS m/z: 312.0/313. 9 (M+).

Example 1 Synthesis of 6-amino-2-phenylamino-1-phenyl-lH-pyrimidin-4-one

A mixture of 6-amino-2-methylthio-1-phenyl-1H-pyrimidin-4-one (2.33g, lOmmol) (obtained in preparation 2) and aniline (4.6g, 50mmol) in presence of catalytic amount of concentrated hydrochloric acid was heated at 120-130 °C for 7 hours. The reaction mixture was cooled, filtered and washed with hexane. The obtained crude product was recrystallised from ethanol to provide the title compound (1.13g, 40.6%, purity 99.5% by HPLC), mp 202-206 °C. lH-NMR (DMSO-d6): 8 5.09 (s, 1H), 6.96-7. 03 (m, 2H), 7.24 - 7. 30 (m, 4H), 7.40-7. 42 (m, 2H), 7.59-7. 61 (m, 2H), 8.74 (s, 1H, D20 exchangeable), 8.94 (s, 1H, D20 exchangeable), 10.0 (s, 1H, D20 exchangeable). IR (KBr) crri 1 : 3302, 3152 (-NH-), 1666 (-C=O). MS m/z: 279.2 (M+).

Example 2 Synthesis of 6-amino-2- (4-methoxy-phenylamino)-1-phenyl-lH-pyrimidin-4-one The title compound was prepared from 6-amino-2-methylthio-1-phenyl-1H-pyrimidin-4- one (1. 5g, 6. 5mmol) (obtained in preparation 2) and 4-methoxyaniline (3.96g, 32mmol) by following the procedure described in example 1 (0.8g, 40.3%, purity 98.4% by HPLC), mp 213-216 °C. lH-NMR (CDC13) : 8 3.73 (s, 3H), 4.9 (s, 1H), 6.87-6. 89 (m, 2H), 7.00 (m, 1H), 7.25-7. 29 (m, 4H), 7.60-7. 62 (m, 2H), 8.73 (bs, 2H, D20 exchangeable), 10.0 (bs, 1H, D20 exchangeable). IR (KBr) cri 1 : 3305,3152 (-NH-), 1678 (-C=O). MS m/z: 309.2 (M+).

Example 3 Synthesis of 6-amino-2- (4-ethoxy-phenylamino)-1-phenyl-lH-pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-1-phenyl-lH-pyrimidin-4- one (l. Og, 4mmol) (obtained in preparation 2) and 4-ethoxyaniline (2.94g, 21mmol) by following the procedure described in example 1 (0.49g, 35.2%, purity 97.1% by HPLC), mp 111-113 °C. lH-NMR (DMSO-d6): 8 1.30-1. 33 (t, 3H), 3. 97-4. 02 (q, 2H), 4.92 (s, 1H), 6.85-6. 87 (m, 2H), 6.99-7. 02 (m, 1H), 7.24-7. 29 (m, 4H), 7.60-7. 62 (m, 2H), 8.72 (bs, 2H, D20 exchangeable), 9.9 (s, 1H, D20 exchangeable). IR (KBr) cm-1: 3308, 2976,1674 (-C=O). MS m/z: 323.3 (M+).

Example 4 Synthesis of 6-amino-2-(4-methylthio-phenylamino)-1-phenyl-1H-pyrimidin-4 -one The title compound was prepared from 6-amino-2-methylthio-1-phenyl-1H-pyrimidin-4- one (3. 0g, 12.8mmol) (obtained in preparation 2) and 4-methylthioaniline (8.85g, 64mmol) by following the procedure described in example 1 (2.26g, 54.1%, purity 92.7% by HPLC), mp 133-135 °C. lH-NMR (DMSO-d6): 8 2.45 (s, 3H), 5.06 (s, 1H), 7.00-7. 04 (m, 1H), 7.18-7. 21 (m, 2H), 7.25-7. 31 (m, 2H), 7.37-7. 42 (m, 2H), 7.58-7. 61 (m, 2H), 8.87-8. 95 (bs, 2H, D20 exchangeable), 10.2 (bs, 1H, D20 exchangeable). IR (KBr) cni I : 3421,1627 (-C=O). MS m/z: 325.2 (M).

Example 5 Synthesis of 6-amino-2- (4-methyl-phenylamino)-1-phenyl-lH-pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-1-phenyl-1H-pyrimidin-4- one (2. 0g, 8. 58mmol) (obtained in preparation 2) and 4-methylaniline (4.59g, 42. 9mmol) by following the procedure described in example 1 (1.33g, 53%), purity 98. 4% by HPLC), mp 207-210 °C. 1H-NMR (DMSO-d6): 5 2.25 (s, 3H), 5.02 (s, 1H), 6.98-7. 10 (m, 3H), 7.23-7. 30 (m, 3H), 7.39-7. 60 (m, 3H), 8.63-8. 90 (m, 2H, D20 exchangeable), 9.93 (bs, 1H, D20 exchangeable). IR (KBr) cm' : 3306,1630 (-C=O). MS m/z: 293.1 (M+).

Example 6 Synthesis of 6-amino-2-(4-chloro-phenylamio)-1-phenyl-1H-pyrimidin-4-one The title compound was prepared from 6-amino-2-methylthio-1-phenyl-1H-pyrimidin-4- one (2. 0g, 8. 58mmol) (obtained in preparation 2) and 4-chloroaniline (5.47g, 42. 9mmol) by following the procedure described in example 1 (1.2g, 45%, purity 98.9% by HPLC), mp 233-237 °C. 1H-NMR (DMSO-d6): 8 5.07 (s, 1H), 7.0-7. 06 (m, 1H), 7.24-7. 34 (m, SH), 7.40-7. 42 (m, 2H), 7.52-7. 54 (m, 2H), 8. 8-9. 01 (bs, 2H, D20 exchangeable). IR (KBr) cm-1 : 3424,1627 (-C=O). MS m/z: 313 (M+).

Example 7 Synthesis of 6-amino-2-(4-fluoro-phenylamio)-1-phenyl-1H-pyrimidin-4-one The title compound was prepared from 6-amino-2-methylthio-1-phenyl-lH-pyrimidin-4- one (2. 0g, 8. 58mmol) (obtained in preparation 2) and 4-fluoroaniline (4.76g, 42. 9mmol) by following the procedure described in example 1 (0. 8g, 31%, purity 98.3% by HPLC), mp 225-227 °C. lH-NMR (DMSO-d6): 8 4.95 (s, 1H), 6.99-7. 56 (m, 9H), 8. 73 (bs, 1H, D20 exchangeable), 8.92 (bs, 1H, D20 exchangeable), 10 (bs, D20 exchangeable). IR (I (Br) cm~l : 3295,1637 (-C=O). MS m/z : 297.3 (M+).

Example 8 Synthesis of 6-amino-1- (4-methylphenyl)-2- (4-methylthio-phenylamino)-1H- pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-l- (4-methylphenyl)-lH- pyrimidin-4-one (lg, 4mmol) (obtained in preparation 3) and 4-methylthioaniline (1. 112g, 8mmol) by following the procedure described in example 1 (0.45g, 32.8%, purity 94.8% by HPLC), mp 231-234 °C. lH-NMR (DMSO-d6) : 8 2.26 (s, 3H), 2.45 (s, 3H), 5.0 (s, 1H), 7.08-7. 12 (m, 2H), 7.18-7. 22 (m, 3H), 7.36-7. 56 (m, 4H), 8. 93-8.96 (m, 2H, D20 exchangeable). IR (KBr) cm' 3303,1627 (-C=O). MS m/z: 339.1 (M+).

Example 9 Synthesis of 6-amino-1-(4-methoxyphenyl)-2-phenylamino-lH-pyrimidin-4-one The title compound was prepared from 6-amino-2-methylthio-l- (4-methoxyphenyl)-lH- pyrimidin-4-one (1. 5g, 5. 7mmol) (obtained in preparation 4) and aniline (2.65g, 28. 5mmol) by following the procedure described in example 1 (0.41g, 23%, purity 97.1% by HPLC), mp 180-190 °C. lH-NMR (DMSO-d6) : b 3.72 (s, 3H), 4.95 (s, 1H), 6.85- 6.87 (m, 3H), 7.2-7. 30 (m, 3H), 7.5-7. 6 (m, 3H), 8. 4 (bs, 1H, D20 exchangeable), 8.8 (bs, 1H, D20 exchangeable), 9.8 (bs, 1H, D20 exchangeable). IR (KBr) cm-1: 3401 (NH), 1630 (-C=O). MS m/z: 309.2 (M+).

Example 10 Synthesis of 6-amino-1-(4-ethoxyphenyl)-2-phenylamino-1H-pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-l- (4-ethoxyphenyl)-lH- pyrimidin-4-one (2. 0g, 7.2mmol) (obtained in preparation 5) and aniline (3.2g, 35mmol) by following the procedure described in example 1 (0.71g, 30%, purity 98% by HPLC), mp 114-118 °C. lH-NMR (DMSO-d6): b 1. 30-1. 33 (t, 3H), 3.97-4. 02 (q, 2H), 5.01 (s, 1H), 6. 85-7. 60 (m, 9H), 8.45 (bs, 1H, D20 exchangeable), 8. 88 (bs, 1H, D20 exchangeable), 10.0 (bs, 1H, D20 exchangeable). IR (KBr) cm-1 : 3309 (-NH-), 1628 (- C=O). MS m/z: 323.2 (M+).

Example 11 Synthesis of 6-amino-1-(4-chlorophenyl)-2-phenylamino-1H-pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-l- (4-chlorophenyl)-lH- pyrimidin-4-one (2. 0g, 7. 48mmol) (obtained in preparation 6) and aniline (3.48g, 37.4mmol) by following the procedure described in example 1 (1.21g, 52%, purity 95.7% by HPLC), mp 216-222 °C. lH-NMR (DMSO-d6): 8 5.15 (s, 1H), 6.97-7. 02 (m, 1H), 7.26-7. 32 (m, 4H), 7.40-7. 71 (m, 5H), 8.94 (s, 1H, D20 exchangeable), 10.4 (bs, 1H, D20 exchangeable). IR (KBr) cm~l : 3306, 1678 (-C=O). MS m/z: 313.1 (M+).

Example 12 Synthesis of 6-amino-1-(4-bromophenyl)-2-phenylamino-lH-pyrimidin-4-one

The title compound was prepared from 6-amino-2-methylthio-l- (4-bromophenyl)-lH- pyrimidin-4-one (l. Og, 3. 2mmol) (obtained in preparation 7) and aniline (0.57g, 6mmol) by following the procedure described in example 1 (0.6g, 52.5%, purity 92. 1% by HPLC), mp 211-213 °C. lH-NMR (DMSO-d6): 8 5.1 (bs, 1H), 6.9-7. 0 (m, 1H), 7.29-7. 43 (m, 8H), 8.92-9. 0 (bm, 2H, D20 exchangeable). IR (I (Br) cm-l : 3320, 1633 (-C=O). MS m/z: 357/358.9 (M+).

Described below are the examples of pharmacological assays used for finding out the efficacy of the compounds of the present invention wherein their protocols and results are provided.

Rat Carraveenan Paw Edema Test The carrageenan paw edema test was performed as described by Winter et al (Proc. Soc.

Exp Biol Me., 111, 544,1962). Male Wistar rats were selected and the body weight were equivalent within each group. The rats were fasted for eighteen hours with free access to water. The rats were dosed orally with the test compound suspended in vehicle containing 0.5% methylcellulose. The control rats were administered the vehicle alone. After one hour the rats were injected with 0.1 ml of 1% Carrageenan solution in 0.9% saline into the sub plantar surface of the right hind paw. Paw thickness was measured using vernier calipers at 0 time, after 2 and 3 hours. The average of foot swelling in drug treated animals was compared with that of control animals. Anti-inflammatory activity was expressed as the percentage inhibition of edema compared with control group [Arzrieim-Forsch/Drug Res 43 (I), 1,44-50, 1993; Otterness and Bliven, Laboratory Models for Testing NSAIDs, In Non-Steroidal Anti-Inflammatory Drugs, (J. Lombardino, ed. 1985)]. The data of the selected compounds in this invention are summarized in Table I. In order to evaluate their role on the ulcer formation, the animals were sacrificed by cervical dislocation, the

stomach removed and flushed with 1% formalin (10ml). The stomach was opened along the greater curvature. The haemorrhagic puncta and sulci were identified macroscopically.

The presence or absence of stomach lesions was scored. The incidence of ulceration was calculated from the number of rats that showed atleast one gastric ulcer or haemorrhagic erosion.

Table I Example Rat Paw Edema model Gastro-ulcerogenic potential No. % Inhibition (% incidence of ulceration) (lOmg/kg body weight) 1 10 24. 6 In vitro evaluation of Cvcloxvgenase-2 (COX-2) inhibition activity The compounds of this invention exhibited in vitro inhibition of COX-2. The COX-2 inhibition activity of the compounds illustrated in the examples was determined by the following method.

Human Whole Blood Assay Human whole blood provides a protein and cell rich milieu appropriate for the study of biochemical efficacy of anti-inflammatory compounds such as selective COX-2 inhibitors.

Studies have shown that normal human blood does not contain COX-2 enzyme. This is correlating with the observation that COX-2 inhibitors have no effect on prostaglandin E2 (PGE2) production in normal blood. These inhibitors are active only after incubation of human blood with lipopolysaccharide (LPS), which induces COX-2 production in the blood.

Method Fresh blood was collected in tubes containing potassium EDTA by vein puncture from male volunteers. The subjects should have no apparent inflammatory conditions and not taken NSAIDs for atleast 7 days prior to blood collection. Blood was treated with aspirin in vitro (101lg/ml, at time zero) to inactivate COX-1, and then with LPS (101lg/ml) along with test agents or vehicle. The blood was incubated for 24 h at 37 °C, after which the tubes were centrifuged, the plasma was separated and stored at-80 °C (J Pharmacol Exp Ther 271,1705, 1994; Proc Natl Acad Sci USA 96,7563, 1999). The plasma was assayed for PGE2 using Cayman ELISA kit as per the procedure outlined by the manufacturer (Cayman Chemicals, Ann Arbor, USA). The plasma was also tested for TNF-a, IL-10, and IL-6 using appropriate human ELISA kit as per the procedure of manufacturer (Cayman Chemicals, Ann Arbor, USA). Representative results of COX-2 inhibition are shown in Table II.

Table II Example No. Cone. (uM) COX-2 % Inhibition 1 10 75. 76 10 1 33. 26

Tumor Necrosis Factor Alpha (TNF-a) This assay determines the effect of test compounds on the production of TNF-a from human monocytes. Compounds were tested for their ability to downregulate the production of TNF-a in activated monocytes. Test compounds were incubated for three, six and twenty four hours with human monocytes. Lipopolysaccharide was used to stimulate the monocytes. The level of TNF-a was quantitated using Enzyme-Linked Immunosorbent assay performed in a 96 well format. Representative results of TNF-a inhibition are shown in Table III.

Table III Example No. Conc. (M) TNF-a % Inhibition 3 1 58. 34 4 10 43. 53 5 10 47. 52 9 10 45. 20 Interleukin-6 (IL-6) This assay determines the effect of test compounds on the production of IL-6 from human monocytes. Compounds are tested for their ability to downregulate the production of IL-6 in activated monocytes. Test compounds were incubated for three, six and twenty four hours with human monocytes. Lipopolysaccharide was used to stimulate the monocytes.

The level of Interleukin-6 is quantitated using Enzyme-Linked Immunosorbent assay performed in a 96 well format. Representative results of IL-6 inhibition are shown in Table IV.

Table IV Example No. Conc. (µM) IL-6 % Inhibition 1 0. 25 46. 59 2 1 65. 10 3 1 82. 29 4 1 56. 73 9 1 75. 39 6 1 44. 62 11 1 59. 46

Inhibitory Action on Adjuvant Arthritis Compounds were assayed for their activity on rat adjuvant induced arthritis according to Theisen-Popp et al. , (Agents Actions 42,50-55, 1994). Six-seven weeks old, Wistar rats were weighed, marked and assigned to groups [a negative control group in which arthritis was not induced (non-adjuvant control), a vehicle-treated arthritis control group, test substance treated arthritis group]. Adjuvant induced arthritis was induced by an injection of Mycobacterium butyricum (Difco) suspended in liquid paraffin into the sub-plantar region of the right hind paw (J Pharmacol Exp Ther, 284,714, 1998). Body weight, contra-lateral paw volumes were determined at various days (0,4, 14,21) for all the groups. The test compound or vehicle was administered orally beginning post injection of adjuvant and continued for 21 days. On day 21, body weight and paw volume of both right and left hind paw, spleen, and thymus weights were determined., In addition, the radiograph of both hind paws was taken to assess the tibio-tarsal joint integrity. Hind limb below the stifle joint was removed and fixed in 1% formalin saline. At the end of the experiment, plasma samples were analysed for cytokines, interleukins and prostaglandins.

The presence or absence of lesions in the stomachs was also observed.

Two-factor ('treatment'and'time') Analysis of Variance with repeated measures on'time' were applied to the % changes for body weight and foot volumes. A post hoc Dunnett's test was conducted to compare the effect of treatments to vehicle. A one-way Analysis of Variance was applied to the thymus and spleen weights followed by the Dunnett's test to compare the effect of treatments to vehicle. Dose-response curves for % inhibition in foot volumes on days 4,14 and 21 were fitted by a 4-parameter logistic function using a nonlinear Least Squares'regression. IDso was defined as the dose corresponding to a 50% reduction from the vehicle and was derived by interpolation from the fitted 4-parameter equation

In-vitro Anti-Cancer activity The compounds of the present invention were also tested for anticancer activity.

Each test compound was screened against a battery of 60 human cell lines obtained from eight organs. The cell suspensions were diluted according to the particular cell type and the target cell density (5000-40,000 cells per well based on cell growth characteristics) was added into 96-well micro titer plates. Inoculates were allowed a pre-incubation period of 24 h at 37 °C for stabilization. Dilutions at twice the intended test concentrations were added at time zero in 100 p1 aliquots to micro titer plate wells. Usually test compounds were evaluated at five 10-fold dilutions. The highest well concentration used in the test is 10-4 M. The cells were then incubated in the presence of the test compound for further 48 h in 5% C02 atmosphere and 100% humidity. After completion of the incubation period the adherent cells were fixed to the plate by means of trichloroacetic acid. After three to five times washing, the cell layer was treated with the protein stain Sulforhodamine B. The optical density, which is proportional to protein mass, was then read by spectrophotometric plate readers at a wavelength of 515 nm.