Aminopyrazole derivs. constitute the first class of nonpeptidic rationally designed b-sheet ligands. Here we describe a double solid-phase protocol for both synthesis and affinity testing. The presented solid-phase synthesis of four types of hybrid compds. relies on the Fmoc strategy and circumvents subsequent HPLC purifn. by pptg. the final product from org. soln. in pure form. Hexa- and octapeptide pendants with internal di- and tetrapeptide bridges are now amenable in high yields to combinatorial synthesis of compd. libraries for high-throughput screening purposes. Solid-phase peptide synthesis (SPPS) on an acid-resistant PAM allows us, after PMB deprotection, to subject the free aminopyrazole binding sites in an immobilized state to on-bead assays with fluorescence-labeled peptides. From the fluorescence emission intensity decrease, individual binding consts. can be calcd. via ref. curves by simple application of the law of mass action. Gratifyingly, host/guest complexation can be monitored quant. even for those ligands, which are almost insol. in water.