WAY-267，464 (1) and twelve conformationally rigid analogues (3a-f-4a-f) were synthesised， characterised and evaluated in cellular assays with the aim of systematically exploring interactions with the oxytocin receptor (OTR). Each analogue was evaluated in radioligand binding displacement assays at both human OTR and arginine vasopressin 1a receptors (VR). Physiological characterisation was determined by whole cell IP1 accumulation assays on stably transfected human embryonic kidney (HEK) cells. Incorporation of the rigid， optionally substituted benzene ring abolished OTR activity and diminished VR pharmacology when compared to 1. A general trend was observed in VR affinity for the propyl analogues (3d-3f) which identified the ortho-substituted analogue as the best in series (Ki?=?251?nM) followed by a decrease in affinity through the meta and para-derivatives (3e; Ki?=?874?nM and 3f; Ki?=?1756?nM respectively). This study confirms the importance of the central pharmacophoric motifs of WAY-267，464 and illuminates the differences in the binding pocket of the highly conserved OTR and VR.