A process for preparing a compound of formula (I): ##STR00001## or a
tautomeric form thereof or a pharmaceutically acceptable salt thereof, or
a pharmaceutically acceptable solvate thereof, wherein: A.sup.1
represents a substituted or unsubstituted aromatic heterocyclyl group;
R.sup.1 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; A.sup.2
represents a benzene ring having in total up to five substituents; and n
represents an integer in the range of from 2 to 6, which process
comprises catalytically reducing a compound of formula (II): ##STR00002##
wherein A.sup.1, R.sup.1, A.sup.2 and n are as defined in relation to
formula (I), characterised in that the reduction reaction is carried out
using a hydrogen pressure above 20 psi; and thereafter if required
forming a pharmaceutically acceptable salt and/or a pharmaceutically
acceptable solvate of the compound of formula (I).