Identification of Dihydrofuro[3,4-<i>d</i>]pyrimidine Derivatives as Novel HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors with Promising Antiviral Activities and Desirable Physicochemical Properties

To address drug resistance to HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs), a series of novel diarylpyrimidine (DAPY) derivatives targeting "tolerant region I" and "tolerant region II" of the NNRTIs binding pocket (NNIBP) were designed utilizing a structure-guided scaffold-hopping strategy. The dihydrofuro[3,4- d]pyrimidine derivatives 13c2 and 13c4 proved to be exceptionally potent against a wide range of HIV-1 strains carrying single NNRTI-resistant mutations (EC₅₀ = 0.9-8.4 nM), which were remarkably superior to that of etravirine (ETV). Meanwhile, both compounds exhibited comparable activities with ETV toward the virus with double mutations F227L+V106A and K103N+Y181C. Furthermore, the most active compound 13c2 showed favorable pharmacokinetic properties with an oral bioavailability of 30.96% and a half-life of 11.1 h, which suggested that 13c2 is worth further investigation as a novel NNRTI to circumvent drug resistance.