A library of 1,296 1,4-benzodiazepines was prepared on 160 microM Tentagel beads. Compounds are attached to the beads using orthogonally cleavable linkers. The library was first screened as pools of 30 beads where 50% of the material is released and screened. GW405212X, a selective oxytocin antagonist, was identified by picking single beads from active pools.