Table 2. Inhibitory potency against FAAH.

Compound	R	Inhibition of FAAH IC50 a (μM)
17	H	0.11
26	5-F	0.13
27	5-Cl	0.41
28	5-CH3	0.70
29	5-OCH3	0.36
30	5-CN	0.97
31	4-F	0.11
32	6-F	0.046
33	7-F	0.052
34		0.41
38		0.18

^aValues are the means of at least two independent determinations, errors are within ±20%.