Synthesis and evaluation of 2-pyridinone derivatives as HIV-1-specific reverse transcriptase inhibitors. 4. 3-[2-(Benzoxazol-2-yl)ethyl]-5-ethyl-6-methylpyridin-2(1H)-one and analogs

A new series of potent specific 2-pyridinone reverse transcriptase (RT) inhibitors was developed based on the preliminary development lead 3-[(phthalmido)ethyl]-5-ethyl-6-methylpyridin-2(1H)-one (3), a non-nucleoside derivative which exhibited weak antiviral activity in cell culture against HIV-1 strain IIIB. One compound, 3-[(benzoxazol-2-yl)ethyl]-5-ethyl-6-methylpyridin-2(1H)-one (9,L-696,229), which was a highly selective antagonist of the RT enzyme (IC50 = 23 nM) and which inhibited the spread of HIV-1 IIIB infection by > 95% in MT4 human T-lymphoid cell culture (CIC95 = 50-100 nM), was selected for clinical evaluation as an antiviral agent.