The invention provides compounds of general formulae I - IV or pharmaceutically acceptablesalts thereof : Formulas (I), (II), (III), (IV) The invention also provides methodsof preparing the compounds, pharmaceutical compositions comprising the compoundsand use of the compounds for the preparation of medicaments intended to modulatethe activity of one or more members of the G-protein coupled receptor (GPCR) class.Compounds of the invention may be used to create a compound library for use in screeningfor agents which modulate signalling through GPCRs.