Table 6.

tert-Butyl Modifications and Replacements.

Cmpd	R1	R2	clogPa	GT1a EC50b	GT1b EC50b	40% HuS EC50c	40% HuS EC90c	Caco2 ABa	Caco2 ERf
23	H		3.01	5	3	7	39	0.19	77
24	H		2.79	16	8	30	195	0.36	52
25	H		4.85	2	--	7d	104d	--	--
26	H		4.15	10	4	41	286	1.56	3.6
27	F		4.47	30	8	85	566	--	--

^aCalculated log P

^bEC₅₀ measured using GT 1a or GT 1b stable HCV subgenomic replicon, nM (n ≥ 2)

^cEC₅₀ and EC₉₀ measured using GT 1b (accept where noted) stable HCV subgenomic replicon in the presence of 40% human serum (HuS), nM (n ≥ 2)

^dGT 1a used

^epermeability coefficient, 10⁻⁶ cm/s

^fratio of BA/AB permeability coefficients.