"Novel Compounds"

Compounds of formula (I) : (formula) or a tautomeric form thereof, or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof, wherein: A1 represents a sustituted or unsubstituted aromatic heterocyclyl group; R1 represents a hydrogen atom, an alkyl group, an acyl group, an aralkyl group, wherein the aryl moiety may be substituted or unsubstituted, or a substituted or unsubstituted aryl group; R2 and R3 each represent hydrogen, or R2 and R3 together represent a bond; A2 represents a benzene ring having in total up to five substituents; and n represents an integer in the range of from 2 to 6; pharmaceutical compositions containing such compounds and the use of such compounds and compositions in medicine.