Fragment hopping-based discovery of novel sulfinylacetamide-diarylpyrimidines (DAPYs) as HIV-1 nonnucleoside reverse transcriptase inhibitors.

The fragment hopping approach is widely applied in drug development. A series of diarylpyrimidines (DAPYs) were obtained by hopping the thioacetamide scaffold to novel human immunodeficiency virus type 1 (HIV-1) nonnucleoside reverse transcriptase inhibitors (NNRTIs) to address the cytotoxicity issue of Etravirine and Rilpivirine. Although the new compounds (11a-l) in the first-round optimization possessed less potent anti-viral activity, they showed much lower cytotoxicity. Further optimization on the sulfur led to the sulfinylacetamide-DAPYs exhibiting improved anti-viral activity and a higher selectivity index especially toward the K103N mutant strain. The most potent compound 12a displayed EC50 values of 0.0249 μM against WT and 0.0104 μM against the K103N mutant strain, low cytotoxicity (CC50 > 221 μM) and a high selectivity index (SI WT > 8873, SI K103N > 21186). In addition, this compound showed a favorable in vitro microsomal stability across species. Computational study predicted the binding models of these potent compounds with HIV-1 reverse transcriptase thus providing further insights for new developments.