6020
E. Elzein et al. / Bioorg. Med. Chem. Lett. 14 (2004) 6017–6021
Table 2. Comparison of pharmacokinetic properties of 1, 7 [(R)-CVT-
4325], and 30
References and notes
1. Schofield, R. S.; Hill, J. A. Am. J. Cardiovasc. Drugs 2001,
1, 23.
2. McCormack, J. G.; Stanley, W. C.; Wolf, A. A. Gen.
Pharmac. 1998, 30, 639.
3. McCormack, J. G.; Barr, R. L.; Wolf, A. A.; Lopaschuk,
G. D. Circulation 1996, 93, 135.
Compound Oral
%F AUC
(ngh/mL)b IV
t1/2 (h)c Plasma
clearance
(species)
dosea
MPK
(mL/min/kg)c
1 (rat)
7 (rat)
2
2
4
2
5
19
38
93
29
30
30.5
282
1.4
3.2
54.5
22.5
12.2
19.7
4.6
7 (dog)
30 (rat)
30 (dog)
1776
253
13.6
4.0
4. Nedergaard, J.; Cannon, B. Meth. Enzymol. 1979, 55, 3.
5. Elzein, E.; Shenk, K. D.; Ibrahim, P.; Marquart, T. A.;
Kerwar, S.; Meyer, S.; Ahmed, H.; Zeng, D.; Chu, N.;
Soohoo, D.; Wong, S.; Leung, K.; Zablocki, J. A. Bioorg.
Med. Chem. Lett. 2004, 14, 973.
6. Zablocki, J.; Elzein, E.; Nudelman, G.; Marquart, T.;
Varkhedkar, V.; Ibrahim, P.; Palle, V. P.; Blackburn, B.
K. World Patent 01/62744 A2, August 30, 2001.
7. Koltun, D. O.; Marquart, T. A.; Shenk, K. D.; Elzein, E.;
Li, Y.; Nguyen, M.; Kerwar, S.; Zeng, D.; Chu, N.;
Soohoo, D.; Hao, J.; Maydanik, V. Y.; Lustig, D. A.; Ng,
K.-J.; Fraser, H.; Zablocki, J. A. Bioorg. Med. Chem. Lett.
2004, 14, 535.
8. Ibrahim, P.; Shenk, K.; Elzein, E.; Palle, V.; Zablocki, J.;
Rehder, K. World Patent 03/008411 A1, January 30, 2003.
9. Piperazine 3 (24.4g), 3-chloromethyl-5-(4-trifluoromethyl-
phenyl)1,2,4-oxadiazole (20.8g, Maybridge Plc, UK),
ethanol (400mL), and diisopropylethylamine (55.3mL)
were warmed at 70ꢁC for 16h (TLC 3:1 hexanes/ethyl
acetate). After concentration in vacuo, the reaction was
diluted with water (500mL), extracted with ethyl acetate
(2 · 500mL), and dried (MgSO4). After concentration in
vacuo (yellow powder obtained), trituration with minimal
amounts of 3:1 mixture of hexanes and ethyl acetate
resulted in a white powder, 31.5g (74% yield) of 7 (CVT-
4325). 1H NMR (400MHz, CDCl3, d): 8.28 (d, 2H,
J = 8.4Hz); 7.79 (d, 2H, J = 8.0Hz); 7.64 (d, 1H, J =
8.8Hz); 7.42 (br s, 1H); 7.00 (dd, 1H, J = 8.4, 2.4Hz);
4.30–4.20 (m, 1H); 4.09–4.02 (m, 2H); 3.83 (s, 2H); 3.50
(br s, 1H); 2.80 (s, 3H); 2.90–2.50 (m, 10H). MS (ESI+,
m/z): 534.98.
1093
65.0
a PO formulation: propylene glycol:0.1N HCl:Tween 80:0.5% carb-
oxycellulose = 20:5:0.4:74.6 (v:v:v:v). Final concentrations in for-
mulation: 2–5mg/mL.
b Dose adjusted oral AUC normalized to 1mg/kg.
c IV formulation: propylene glycol:0.1N HCl:saline water = 20:5:75
(v/v/v). Final concentration in formulation: 1mg/mL (1mg/kg dose).
and therefore, it was not further evaluated in dogs. The
lead compounds 7 and 30 were evaluated in both rat and
dog, and the results are shown in Table 2. Both amide
surrogate compounds 7 and 30 have clearly superior
PK profiles relative to anilide 1 based on comparison
of AUC, t1/2, and clearance in the rat. A closer compar-
ison of 7 and 30 demonstrated that 7 has higher oral bio-
availability in both rats and dogs. However, 30 has a low
clearance and extremely long half-life in dogs. We fur-
ther compared the rates of disappearance of 7 and 30
by liver microsomes from rats and dogs and confirmed
that while metabolism rates of these two compounds
were similar in rat liver microsomes, 30 was metaboli-
cally more stable than 7 in dog liver microsomes (74%
and 62% parent @ 30min, respectively). This small dif-
ference in the in vitro metabolism between 7 and 30 does
not account for the observed decrease in plasma clear-
ance and increase in oral bioavailability in dogs found
with 30 that maybe attributed to many factors including
a possible diminishment in N-dealkylation of the core
piperazine ring, a known route of metabolism for
ranolazine.17
10. Natero, R.; Koltun, D. O.; Zablocki, J. A. Synth.
Commun. 2004, 34(14), 1–7.
11. To a solution of 2-(S)-methylpiperazine (5.0g, 50mmol),
triethylamine (1.25g, 12.5mmol) and chloroform (30mL)
was added dropwise Boc-ON (2.0g, 8.3mmol) in chloro-
form (15mL) at 23ꢁC. After 15h, the reaction mixture was
washed with water (2 · 50mL), dried (sodium sulfate), and
purified by application of flash chromatography (metha-
nol:methylene chloride 1:10) to afford the N-4-Boc-2-(S)-
methylpiperazine. This piperazine derivative was reacted
with 5-(((R)-oxiran-2-yl)methoxy)-2-methylbenzo[d]thiaz-
ole by warming to reflux in ethanol then deprotected with
TFA.
In conclusion, the introduction of a para-trifluoro-
methyl-5-phenyl-1,2,4-oxadiazole, 7 (CVT-4325), as an
amide surrogate resulted in both good palmCoA inhibi-
tion (IC50 = 380nM) and a favorable PK profile
(F = 93%, t1/2 = 13.6h, n = 3, dog). Additional pharma-
cological studies demonstrate that 7 produces a meta-
bolic shift from fatty acids to glucose, and this finding
is disclosed elsewhere.18
12. Borg, S.; Estenne-Bouhtou, G.; Luthman, K.; Csoregh, I.;
Hesselink, W.; Hacksell, U. J. Org. Chem. 1995, 60, 3112–
3120.
Acknowledgements
13. Borg, S.; Vollinga, R. C.; Labarre, M.; Payza, K.;
Terenius, L.; Luthman, K. J. Med. Chem. 1999, 42,
4331–4342.
14. Biftu, T.; Feng, D. D.; Liang, G. B.; Kuo, H.; Qian, X.;
Naylor, E. M.; Colandrea, V. J.; Candelore, M. R.;
Cascieri, M. A.; Colwell, L. F., Jr.; Forrest, M. J.; Hom,
G. J.; MacIntyre, D. E.; Stearns, R. A.; Strader, C. D.;
Wyvratt, M. J.; Fisher, M. H.; Weber, A. E. Bioorg. Med.
Chem. Lett. 2000, 10, 1431–1434.
We would like to thank Dr. Brent Blackburn, and Dr.
Luiz Belardinelli, for valuable input and discussions.
Supplementary data
Supplemental materials are available online that include
the conditions of the PalmCoA assay. Supplementary
data associated with this article can be found, in the on-
15. Feng, D. D.; Biftu, T.; Candelore, M. R.; Cascieri, M. A.;
Colwell, L. F., Jr.; Deng, L.; Feeney, W. P.; Forrest, M. J.;
Hom, G. J.; MacIntyre, D. E.; Miller, R. R.; Stearns, R.
A.; Strader, C. D.; Tota, L.; Wyvratt, M. J.; Fisher, M. H.;