The invention relates to compounds of the general formula I: ##STR1## or a salt thereof, in which A represents a pyridine ring or a halogen substituted pyridine ring, R.sub.1 represents hydrogen, alkyl (1-6 C), alkoxy (1-6 C), alkylthio (1-6 C), halogen, OH, SH or CF.sub.3 R.sub.2 represents hydrogen or a lower alkyl or aralkyl group and n and m may each be 1, 2 or 3 with the proviso that the sum of m and n must be 2, 3 or 4, having CNS activity, a pronounced antihistamine activity and little or no antiserotonin activity.