Pyridazino(4,5-b)(1,5)oxazepinone, -thiazepinone and -diazepinone compounds

A pharmaceutical composition comprising at least one pyridazino(4,5-b)(1,5)oxazepinone, -thiazepinone or -diazepinone compound of formula (I),

• wherein
• R stands for hydrogen atom or a group of formula NHR4, wherein R4 stands for hydrogen, C1-4alkyl or C2-5acyl group,
• R1 stands for C1-4alkyl or C2-4alkenyl group, which may be substituted by a phenyl group, or phenyl group,
• W stands for methylene or carbonyl group,
• X and Y stand independently for oxygen or sulphur atom, SO, SO2 or NR3 group,
• wherein R3 is hydrogen atom, C1-4alkyl group or a group of formula (II),
• wherein R2 stands for hydrogen or halogen atom, C1-4alkoxy or nitro group or a group of formula NHR4, wherein R4 has the above meaning, and Z stands for methylene or carbonyl group, further n has a value of 0, 1 or 2,
• with the proviso that when any of X or Y stands for oxygen or sulphur atom, SO or SO2 group or a group of formula NR3, wherein R3 stands for hydrogen atom or C1-4alkyl group, then the other may stand only for an NR3 group, wherein R3 stands for a group of formula (II), wherein R2, Z and n have the above meanings,
• or a tautomer or an acid-addition salt of all these compounds in admixture with solvents, diluents, carriers and/or additives commonly used in the pharmaceutical industry.