Identification and optimisation of novel sulfonamide, selective vasopressin V1B receptor antagonists

The synthesis and preliminary structure-activity relationships (SAR) of a novel class of vasopressin V(1B) receptor antagonists are described. Hit compound 5, identified via high throughput screening of the corporate collection, showed good activity in a V(1B) binding assay (K(i) 63 nM) but did not possess the lead-like physicochemical properties typically required in a hit compound. A 'deletion approach' on the HTS hit 5 was performed, with the focus on improvement of physicochemical properties, yielding the selective V(1B) antagonist 9f (K(i) 190 nM), with improved druglike characteristics.