| abstract |
A 3(2H)-pyridazinone derivative of formula (I), its salt, a process for its production and a pharmaceutical composition containing it, wherein each of R?1, R2 and R3¿ which are independent of one another, is a hydrogen atom or a C¿1-4? alkyl group, X is a chlorine atom or a bromine atom, Y?1¿ is a hydrogen atom, a halogen atom, a nitro group, an amino group or a C¿1-4? alkoxy group, Y?2¿ is a hydrogen atom, a halogen atom, a hydroxyl group, a C¿1-4? alkyl group or a C1-4 alkoxy group, A is a C1-5 alkylene chain which may be substituted by a hydroxyl group, B is a carbonyl group or a methylene chain which may be substitued by a C1-4 alkyl group, and each of R?4 and R5¿ which are independent of each other, is a C¿1-4? alkyl group, or R?4¿ is a hydrogen atom and R5 is -Z-Ar (wherein Z is a C¿1-5? alkylene chain, and Ar is an aromatic 6-membered ring which may contain a nitrogen atom), or R?4 and R5¿ together form a C¿2-6? cyclic alkylene group, or R?4 and R5¿ form together with the adjacent nitrogen atom a 4-substituted piperazine ring of formula (a), wherein R6 is a C¿1-4? alkyl group. |