Described herein are compounds with affinity for the 5-HT6 receptor, which have the general formula I: wherein: R represents a group of Formula II or Formula III; one of A, B D or E is a N atom, the remainder being CH groups; R1 is selected from the group consisting of SO2Ar, C(O)Ar, CH2Ar and Ar; R2, R3 and R4 are independently selected from the group consisting of H and alkyl;  represents a single or double bond, with the proviso that there is only one double bond in the ring at a time; n is an integer of from 1-3; Z is selected from the group consisting of C, CH and N, provided that when  is a double bond, Z is C and when  is a single bond, Z is selected from CH and N; Ar is an optionally substituted aryl group; with the proviso that when R is a group of Formula II, R1 is SO2Ar. Also described is the use of these compounds as pharmaceuticals to treat indications where inhibition of the 5-HT6 receptor is implicated, such as schizophrenia.