Barbituric acid derivatives, processes for their production and pharmaceutical agents containing these compounds

A compound of formula I

• wherein:
• X, Y and Z are each oxygen;
• R1 is phenyl which is unsubstituted or substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, phenyl or phenoxy;
• R2 and R3 are each hydrogen;
• R4 is hydrogen;
• and
• R5 is an acyl residue CO—A—R6, wherein A is a valence bond or a C1-C9 alkylene chain, and R6 is selected from the group consisting of hydrogen, phenyl, naphthalinyl, indolyl, furyl, 9H-fluorenyl, 9-oxo-9H-fluorenyl, pyridinyl and styryl,
• wherein any of the rings designated above for R6 may be substituted one, two or three times independently by a group selected from the group existing of C1-C4 alkyl, C1-C4 alkoxy, halogen, nitro, amino, mono- or dialkylamino, SO2NH2, SCH3, CN, CONH2, CF3, phenoxy, benzoyl and NHCOCH3, or
• R4 and R5, together with the nitrogen atom to which they are linked, form a piperidine or piperazine ring which is substituted by a group selected from the group consisting of hydroxyl, C1-C4 alkyl and C1-C4 alkoxy, wherein when R4 and R5 together with the nitrogen to which they are linked form a piperidine or a piperazine ring, R1 is not a phenyl ring substituted by phenyl or phenoxy,
• or a pharmacologically acceptable salt or optically active form thereof.