5598
J. S. Wai et al. / Bioorg. Med. Chem. Lett. 17 (2007) 5595–5599
OMe
HN
identified. The lead compound 6 inhibits replication of
O
MeO
N
F
HIV-1 in cell culture at CIC95 = 0.31 lM, and exhibits
no significant shift in potency when assayed with addi-
tion of 50% normal human serum. No cytotoxicity is ob-
served in cell culture at concentrations up to 20 lM.
When compound 6 was dosed orally in rat at 10 mg/kg
as a solution in 1% methylcellulose, it displayed good
pharmacokinetic profile and maintained excellent expo-
sure through 24 h of the study. No covalent binding of
compound 6 with microsomal proteins was observed
in both vitro and in vivo models. Further exploration
of this dihydroxypyridopyrazine-1,6-dione template
and analogous bicyclic systems is in progress.
F
a
CHO
17
O
b
16
O
O
F
F
N
c
N
N
O
N
18
O
19
d
O
References and notes
F
N
N
O
1. For a recent review on the structure and function of HIV-1
integrase, see: (a) Davies, D. R.; Chiu, T. K. Curr. Top.
Med. Chem. 2004, 4, 965; (b) Pommier, Y.; Johnson, A.
A.; Marchand, C. Nat. Rev. Drug Discov. 2005, 4, 236; For
a recent review on HIV-1 integrase inhibitors, see:
Gordon, C. P.; Griffith, R.; Keller, P. A. Med. Chem.
2007, 3, 199; Deng, J.; Dayam, R.; Al-Mawsawi, L. Q.;
Neamati, N. Curr. Pharm. Des. 2007, 13, 129; Anthony,
N. J. Curr. Top. Med. Chem. 2004, 4, 979.
OH
OH
6
Scheme 1. Synthesis of compound 6. Reagents: (a) i—
H2NCH2CH(OMe)2, NaBH4, MeOH (82%); ii—N-Acetyl-Gly, EDC,
HOBt, i-Pr2NEt, DMF (95%); (b) MsOH, CH2Cl2 (62%); (c) H2, 5%
Pd/C, EtOH (95%); (d) i—LiHMDS, diethyl oxalate, DMF; ii—excess
LiHMDS (15–20%).
NMR studies of the purified oxalation products led to the
identification of the major component as 20, and one of
the minor oxalation products as 22. Treatment of each
one of them independently with LiHMDS in DMF did
not lead to cyclization product 6. The third oxalation
product readily cyclized to compound 6 upon workup.
However, 20 was readily converted to the third oxalation
product when exposed to a mixture of acetonitrile, water,
and trifluoroacetic acid. NMR data of this material are
consistent with those of structure 21. Treatment of 21 in
DMF with LiHMDS led to the cyclization product 6.
2. Wai, J. S.; Egbertson, M. S.; Payne, L. S.; Fisher, T. E.;
Embrey, M. W.; Tran, L. O.; Melamed, J. Y.; Langford,
H. M.; Guare, J. P., Jr.; Zhuang, L.; Grey, V. E.; Vacca, J.
P.; Holloway, M. K.; Naylor-Olsen, A. M.; Hazuda, D. J.;
Felock, P. J.; Wolfe, A. L.; Stillmock, K. A.; Schleif, W.
A.; Gabryelski, L. J.; Young, S. D. J. Med. Chem. 2000,
43, 4923.
3. For monocyclic pyrimidinone integrase inhibitors, see (a)
Zhuang, L.; Wai, J. S.; Embrey, M. W.; Fisher, T. E.;
Egbertson, M. S.; Payne, L. S.; Guare, J. P., Jr.; Vacca, J.
P.; Hazuda, D. J.; Felock, P. J.; Wolfe, A. L.; Stillmock,
K. A.; Witmer, M. V.; Moyer, G.; Schleif, W. A.;
Gabryelski, L. J.; Leonard, Y. M.; Lynch, J. J., Jr.;
Michelson, S. R.; Young, S. D. J. Med. Chem. 2003, 46,
453; (b) Hazuda, D. J.; Anthony, N. J.; Gomez, R. P.;
Jolly, S. M.; Wai, J. S.; Zhuang, L.; Fisher, T. E.; Embrey,
M. W.; Guare, J. P., Jr.; Egbertson, M. S.; Vacca, J. P.;
Huff, J. R.; Felock, P. J.; Witmer, M. V.; Stillmock, K. A.;
Danovich, R.; Grobler, J.; Miller, M. D.; Espeseth, A. S.;
Jin, L.; Chen, I.-W.; Lin, J.; Kassahun, K.; Ellis, J. D.;
Wong, B. K.; Xu, W.; Pearson, P. G.; Schleif, W. A.;
Cortese, R.; Emini, E.; Summa, V.; Holloway, M. K.;
Young, S. D. Proc. Natl. Acad. Sci. U.S.A. 2004, 101,
11233.
4. Hazuda, D. J.; Young, S. D.; Guare, J. P., Jr.; Anthony,
N. J.; Gomez, R. P.; Wai, J. S.; Vacca, J. P.; Handt, L.;
Motzel, S. L.; Klein, H. J.; Dornadula, G.; Danovich, R.
M.; Witmer, M. V.; Wilson, K. A. A.; Tussey, L.; Schleif,
W. A.; Gabryelski, L. S.; Lin, J.; Miller, M. D.; Casimiro,
D. R.; Emini, E. A.; Shiver, J. W. Science 2004, 305, 528–
532.
5. (a) Summa, V.; Petrocchi, A.; Matassa, V.; Gardelli, C.;
Muraglia, E.; Rowley, M.; Paz, O. G.; Laufer, R.;
Monteagudo, E.; Pace, P. J. Med. Chem 2006, 49, 6646;
(b) Petrocchi, A.; Koch, U.; Matassa, V. G.; Pacini, B.;
Stillmock, K. A.; Summa, V. Biorg. Med. Chem. Lett.
2007, 17, 350.
O
F
N
N
O
19
LiHMDS, DMF
diethyl oxalate
O
O
O
OH
CO2R
N
N
N
+
+
N
CO2R
OH
N
OH
CO2R
20 (major)
N
O
O
O
22 (minor)
21 (minor)
O
N
N
OH
O
OH
6
6. Hazuda, D. J.; Felock, P.; Hastings, J. C.; Pramanik, B.;
Wolfe, A. J. Virol. 1997, 71, 7005, Assays were performed
with recombinant HIV-1 integrase (0.1 lM) preassembled
on immobilized oligonucleotides. Inhibitors were either
In summary, a series of potent dihydroxypyrido-pyra-
zine-1,6-dione HIV-1 integrase inhibitors which inhib-
ited replication of HIV-1 in cell culture has been