Activities and cytotoxicities of rilpivirine (1) and its analogues. EC50s, as measured by reduction of luciferase reporter activity, are reported as nM values, CC50s are reported as μM values. Standard deviations are indicated in parentheses. Shading of EC50 values indicates a log scale: no shading = EC50 <1.0 nM, light gray = EC50 between 1.0 nM and 9.9 nM, dark gray = EC50 between 10 nM and 99nM, black = EC50 ≥100 nM. Therapeutic Index (T.I.) is the ratio of CC50/EC50.