New pyridazinone derivatives, processes for preparing them and medicaments containing them which are useful, in particular, as aldose reductase inhibitors

摘要

The invention relates to new compounds of formulae: <IMAGE> in which: - R1 and R2 represent a hydrogen atom, a lower alkyl, an aryl or aryl(lower alkyl) which may be substituted with a lower alkyl, a halogen, a trifluoromethyl, a methoxy, a methylthio, a methylenedioxy group or a nitro, or R1 and R2 together form a non-aromatic C3-C7 carbon ring, a nitrogenous heterocycle such as pyridine, pyrazine, pyrimidine, pyridazine, indole or pyrazole, a saturated or unsaturated oxygen-containing heterocycle such as pyran or furan or a saturated or unsaturated sulphur-containing heterocycle such as thiopyran or thiophene, it being possible for this heterocycle to be unsubstituted or substituted with a halogen or a lower alkyl; - R3 and R4 represent a hydrogen atom, a lower alkyl, a halogen, a trifluoromethyl, a methoxy, a methylthio or a nitro, or R3 and R4 together form a methylene dioxy group; - R5 represents hydrogen, a lower hydroxyalkyl, a (lower alkanoyl)oxy(lower alkyl) or a lower amino alkyl; - Z is a heterocycle such as pyridine, thiazole, benzothiazole, benzimidazole or quinoline, which may be unsubstituted or substituted with a halogen or a lower alkyl. Lower alkyl is understood to mean a linear or branched or cyclic chain of 1 to 5 carbon atoms. Aldose reductase inhibitors. Treatment of certain complications of diabetes.