To this end, we synthesized a library of derivatives via EDC mediated peptide bond couplings (Figure ). Given high throughput D2B is known for peptide bond formations, we believed it this chemistry be a good test-case for our deconfounding strategy. Thus, 300 amines were chosen, coupled to the commercially available M pro P1, P2 binder, acid 2, and subjected without further purification or separation to fluorogenic M pro assay.