The F2 compound is a NNRTI. A. Isobologram analysis of the effect of combining F2 with either AZT or NVP in human 293T cells challenged with the VSVg-pseudotyped HIV-1 vector. Depicted are isobologram plots for the 90% inhibitory level (EC90). The dashed line indicates the values expected for an additive effect. Values below and to the left of the line indicate synergistic effects. FIC, fractional inhibitory concentration. B. Structure and synthesis of compound F2 compared to THR-50. Reagents: (a) 0.1 M in 1,2-dichloroethane – 2,2,2-trifluoroethanol (1:1), 5.0 mol% Sc(OTf)3, rt for 96h or microwaved at 140°C for 5min, >90% yield; (b) 2,6-F2BzCl, THF/pyridine (5:1), rt for 2h, 55% yield; (c) Fe, AcOH, reflux, 97% yield; (d) 2,6-F2BnBr, NaH, THF, rt overnight, 75% yield.