2,3-diaryl-pyrazolo[1,5-b]pyridazines derivatives, their preparation and their use as cyclooxygenase 2(cox-2) inhibitors

Abstract

The invention provides the compounds of formula (I) and pharmaceutically acceptable derivatives thereof in which: R is halogen, C alkyl, C alkoxy, C alkoxy substituted by one or more fluorine atoms, or O(CH ) NR R ; R and R are independently selected from H, C alkyl, C alkyl, substituted by one or more fluorine atoms, C alkoxy, C hydroxyalkyl, SC alkyl, C(O)H, C(O)C alkyl, C alkylsulphonyl, C alkoxy substituted by one or more fluorine atoms, O(CH ) CO C alkyl, O(CH ) SC alkyl, (CH ) NR R , (CH ) SC alkyl or C(O)NR R ; with the proviso that when R is at the 4-position and is halogen, at least one of R and R is C alkylsulphonyl, C alkoxy substituted by one or more fluorine atoms, O(CH ) CO C alkyl, O(CH ) SC alkyl, (CH ) NR R or (CH ) SC alkyl, C(O)NR R ; R is C alkyl or NH ; R and R are independently selected from H, or C alkyl or, together with the nitrogen atom to which they are attached, form a 4-8 membered saturated ring; and n is 1-4. Compounds of formula (I) are potent and selective inhibitors of COX-2 and are of use in the treatment of the pain, fever, inflammation of a variety of conditions and diseases.