H. Ohta et al. / Bioorg. Med. Chem. Lett. 17 (2007) 6299–6304
6303
12. Ohta, H.; Ishizaka, T.; Yoshinaga, M.; Morita, A.;
Tomishima, Y.; Toda, Y.; Saito, S. Bioorg. Med. Chem.
Lett. 2007, 17, 5133.
(2) presence of a bulky lipophilic group like tert-butyl at
5-position of the thiazole ring was important for obtain-
ing a high affinity for the CB2 receptor, and (3) a 2-
substituted-5-trifluorometylphenyl amide yielded high
affinity and selectivity for the CB2 receptor. These stud-
ies led to compounds 4-9 and 4-27, which showed a com-
bination of good potency for the CB2 receptor and
excellent pharmacokinetics in rats.
13. In vitro metabolic stability expressed as a residual
percentage of parent compound (5 lM) after 15 min.
Procedure: Each compound was incubated with 1.0 mg
protein/mL of the liver microsomal fractions from Xeno-
tech in 250 mM phosphate buffer containing 69 mM KCl
(pH 7.4) at a final drug concentration of 5 lM in the
presence of an NADPH-generating system (2.4 mM
MgCl2, 1.4 mM glucose-6-phosphate, 0.18 U glucose-6-
phosphate dehydrogenase) at 37 °C for 15 min. The
stability of the sample was checked in boiled liver
microsomes fractions. All experiments were performed in
triplicate. After incubation, twofold volume of DMSO
was added to incubation medium, the tube was vortexed
and centrifuged at 2000g (4 °C) for 10 min. The resulting
supernatant was analyzed by LC–MS/MS system.
Supplementary data
Supplementary data associated with this article can be
14. 8-18 and 8-20 are commercially available compounds
(Aldrich Chemical Company, Inc.). 8-19 was prepared
by Ido’s procedure. Ueda, S.; Terauchi, H.; Kawashi-
ma, M.; Yano, A.; Ido, M. Chem. Pharm. Bull. 2004,
52, 634.
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15. Typical procedure: synthesis of N-[5-tert-butyl-3-(cyclo-
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ylcarbodiimide hydrochloride (0.51 g, 2.7 mmol), 1-
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DMF (7.0 ml) was added 7 (0.50 g, 2.2 mmol), and the
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