| abstract |
A compound of formula (I) or, if appropriate, a pharmaceutically acceptable salt thereof; or a pharmaceutically acceptable solvate thereof, wherein R?1 and R2¿ each independently represent a moiety of formula (a): -(CH¿2?)m-A, wherein m represents zero or an integer 1, 2 or 3 and A represents a substituted or unsubstituted cyclic hydrocarbon radical; R?3¿ represents NO¿2?, a halogen atom, a hydroxy group, an alkoxy group or a methyl group substituted with 1 or 2 groups of formula CO2R, wherein R in each group is independently hydrogen or alkyl or a group of formula O-L-A?1¿ wherein L is a bond or a linking group and A1 is a saturated or unsaturated heterocyclic group, or R3 represents a group of formula NRsRt, wherein R?s and Rt¿ each independently represent hydrogen, alkyl, aralkyl, an unsaturated heterocyclic group or R?s and Rt¿ together with the nitrogen to which they are attached form an unsaturated heterocyclic group; and R4 represents an alkyl, aralkyl or an (unsaturated heterocyclyl)alkyl group; a process for preparing such a compound, a pharmaceutical composition containing such a compound and the use of such a compound or composition in medicine. |