Table 1. SAR of the Pendant Benzyl Group.

		IC50 (nM)a
entry	R	hFAAH	rFAAH
3	H	>10000	>10000
4	2-Cl	4670 ± 1100	>10000
5	3-Cl	840 ± 150	5600 ± 860
6	4-Cl	128 ± 60	2670 ± 2000
7	3-F	2470 ± 650	>10000
8	4-F	2770 ± 780	>10000
9	3-CN	6670 ± 2300	10000 ± 0
10	4-CN	4670 ± 1800	7670 ± 1800
11	3-CF3	350 ± 90	830 ± 200
12	4-CF3	50 ± 19	260 ± 70
13	3-OMe	1530 ± 220	>10000
14	4-OMe	490 ± 200	>10000
15	3-OPh	74 ± 14	6670 ± 800
16	4-OPh	2830 ± 1400	>10000
17	3-(4-chlorophenoxy)	6 ± 4	300 ± 90
18	4-(4-chlorophenoxy)	62 ± 28	4000 ± 1000
19	3-(4-methylphenoxy)	11 ± 2.4	640 ± 120
20	3-(4-methoxy-phenoxy)	12 ± 0.7	133 ± 11
21	3-(4-t-butyl-phenoxy)	46 ± 12	75 ± 16

^aThese are apparent IC₅₀ values with values obtained after a 60 min preincubation with the enzyme; n ≥ 3 ± standard error.