Synthesis and anti-HCV activity of a new 2′-deoxy-2′-fluoro- 2′-C-methyl nucleoside analogue

Article abstract of DOI:10.1016/j.bmcl.2010.10.076

2′-Deoxy-2′-fluoro-2′-C-methyl nucleoside analogue 4 was designed and synthesized. Initial biological studies indicated that this compound showed promising activity against HCV replication.

Full text of DOI:10.1016/j.bmcl.2010.10.076

Bioorganic & Medicinal Chemistry Letters 20 (2010) 7297–7298
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Bioorganic & Medicinal Chemistry Letters
journal homepage: www.elsevier.com/locate/bmcl
Synthesis and anti-HCV activity of a new 20-deoxy-20-fluoro-20-C-methyl
nucleoside analogue
Weidong Hu a, Ping’an Wang b, Chuanjun Song a, , Zhenliang Pan c, Qiang Wang a, Xiaohe Guo d, Xuejun Yu d,
⇑
Zhenhua Shen a, Shuyang Wang a, Junbiao Chang a,
⇑
a Department of Chemistry, Zhengzhou University, Zhengzhou, Henan Province 450001, PR China
b College of Chemistry and Chemical Engineering, Henan University, Kaifen, Henan Province 475001, PR China
c School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, Henan Province 450001, PR China
d Hennan Key Laboratory of Fine Chemicals, Henan Academy of Science, No. 56 Hongzhuan Road, Zhengzhou 450002, PR China
a r t i c l e i n f o
a b s t r a c t
20-Deoxy-20-fluoro-20-C-methyl nucleoside analogue 4 was designed and synthesized. Initial biological
studies indicated that this compound showed promising activity against HCV replication.
Ó 2010 Elsevier Ltd. All rights reserved.
Article history:
Received 20 July 2010
Revised 27 September 2010
Accepted 15 October 2010
Available online 4 November 2010
Keywords:
20-Deoxy-20-fluoro-20-C-methyl nucleoside
Anti-HCV activity
It is estimated that hepatitis C virus (HCV) infect 130 million
people worldwide.1 About 50% of the infected cases will become
chronic2 and about 20% of these chronic patients develop liver cir-
rhosis that can lead to hepatocellular carcinoma.3 Unfortunately,
no vaccine is currently available to prevent hepatitis C. The stan-
dard of care for chronic hepatitis C is combination therapy with
of 8 with 2-deoxy-2-fluoro-2-C-methylribofuranose 911 under
Mitsunobu conditions gave the protected nucleoside 10 as a mix-
ture of
chromatography. Displacement of the chloride in the b anomer
with ammonia, followed by deprotection, resulted in the formation
of the desired nucleoside analogue 413 in 85% isolated yield over the
two steps.
The effect of compound 4 on HCV replication was examined
using a HCV subgenomic replicon cell culture system (Ava. 5 cells)
and a Sip-L assisted authentic HCV infection/replication system
(293-Sip-L cells).14 In replicon system, compound 4 partially sup-
a
and b anomers,12 which could be separated by column
an interferon-a and ribavirin, which is effective in only 50% of pa-
tients.4 Clearly, there is an urgent need for effective anti-HCV
agent.
Recently, a series of modified nucleosides with potent inhibitory
activity against the HCV NS5B polymerase have been identified.5
Among these, 20-C-methyl substituted nucleoside analogues, such
as 20-C-methyladenosine 1,6,7 20-C-methylguanosine 2,7 20-C-meth-
ylcytidine 3a8 and its 20-deoxy-20-fluoro analogue 3b8,9 (Fig. 1), are
particularly noteworthy, and 3b is currently in clinical trial. As a
continuous research program of our laboratory searching for antivi-
ral agents,10 we now report the design and synthesis of 20-deoxy-20-
fluoro-20-C-methyl nucleoside analogue 4, which shows promising
activity against HCV replication.
pressed HCV replication at 6 and 0.6
was suppressed to 1/5 of the original level at both concentrations.
No suppression effect could be observed at 0.06 g/mL. In Sip-L as-
lg/mL. The HCV-RNA level
l
sisted HCV replication system, compound 4 suppressed HCV repli-
cation in a dose-dependent manner. The results were shown in
Figure 2. The estimated EC50 of HCV-RNA was 0.8
lg/mL. The IC50
calculated using total cellular RNA was 350 g/mL.
l
In summary, a new 20-deoxy-20-fluoro-20-C-methyl nucleoside
analogue 4 was designed and synthesized. Initial biological studies
indicated that this compound showed promising activity against
HCV replication, thus merited further investigation.
As shown in Scheme 1, selective reduction of thioxo-pyrrolo[2,3-
d]pyrimidinone 5 with Raney-Ni gave pyrrolo[2,3-d]pyrimidinone
6, which was treated successively with phosphorus oxychloride
and Selectfluor to give compound 8 in good overall yield. Coupling
Acknowledgments
⇑
Corresponding authors. Tel.: +86 37167781788.
E-mail addresses: chjsong@zzu.edu.cn (C. Song), changjunbiao@zzu.edu.cn
We are grateful to the National Natural Science Foundation of
China (Outstanding Young Scholarship to J. Chang, #30825043)
(J. Chang).
0960-894X/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2010.10.076

7298
W. Hu et al. / Bioorg. Med. Chem. Lett. 20 (2010) 7297–7298
Figure 1. Anti-HCV nucleoside analogues.
Scheme 1. Reagent and conditions: (a) Raney-Ni, NH3ꢀH2O, reflux, 6 h, 85%; (b) POCl3, reflux, 4 h, 91%; (c) Selectfluor, AcOH, CH3CN, rt, 15 h, 59%; (d) DEAD, PPh3, CH3CN, rt,
24 h, 10% for the anomer, 15% for the b anomer; (e) 0.5 N NH3, 1,4-dioxane, 80 °C, 24 h; (f) NH3/MeOH, rt, 24 h, 85% over the two steps.
a
10. (a) Wang, S.; Chang, J.; Pan, S.; Zhao, K. Helv. Chim. Acta 2004, 87, 327; (b) Zhao,
B.; Chang, J.; Wang, Q.; Du, Y.; Zhao, K. Synlett 2008, 2993; (c) Chang, J.; Yu, X.;
Wang, L.; Wang, Q.; Qi, X.; Dong, C. Faming Zhuanli Shengqing Gongkai
Shuomingshu, CN 1626543, 2005; Chem. Abstr. 2005, 144, 150595.; (d) Chang,
J.; Yu, X.; Bao, X.; Ye, Z. Faming Zhuanli Shengqing Gongkai Shuomingshu, CN
1712409, 2005; Chem. Abstr. 2005, 145, 489507.; (e) Chang, J.; Bao, X.; Wang,
Q.; Guo, X.; Wang, W.; Qi, X. Faming Zhuanli Shengqing Gongkai Shuomingshu,
CN 101177442, 2008; Chem. Abstr. 2008, 149, 32518.; (f) Wang, Q.; Li, Y.; Song,
C.; Qian, K.; Chen, C.-H.; Lee, K.-H.; Chang, J. Bioorg. Med. Chem. Lett. 2010, 20,
4053.
Figure 2. Inhibition of HCV-RNA replication by compound 4.
and the Outstanding Scholar Foundation of Henan Province
(#094100510019) for financial support.
11. Clark, J. L.; Mason, J. C.; Hobbs, A. J.; Hollecker, L.; Schinazi, R. F. J. Carbohydr.
Chem. 2006, 25, 461.
12. 1H NMR (300 MHz, CDCl3) for the b-anomer (less polar spot on TLC): 8.67 (1H,
s), 8.12–7.40 (10H, m), 7.30 (1H, d, J = 2.4 Hz), 6.66 (1H, d, J = 17.6 Hz), 5.84
(1H, dd, J = 22.0, 9.6 Hz), 4.88 (1H, dd, J = 12.6, 2.8 Hz), 4.74 (1H, m), 4.64 (1H,
dd, J = 12.6, 3.6 Hz) and 1.20 (3H, d, J = 22.0 Hz); 1H NMR (300 MHz, CDCl3) for
References and notes
1. Later, M. J. World J. Gastroenterol. 2007, 13, 2436.
2. Cuthbert, J. A. Clin. Microbiol. Rev. 1994, 7, 505.
3. Di Bisceglie, A. M. Hepatology 2000, 31, 1014.
the a-anomer (more polar spot on TLC): 8.62 (1H, s), 8.11–7.36 (11H, m), 6.86
(1H, d, J = 18.2 Hz), 5.81 (1H, dd, J = 21.6, 8.7 Hz), 4.91 (1H, m), 4.72 (1H, dd,
J = 12.2, 3.7 Hz), 4.61 (1H, dd, J = 12.2, 4.6 Hz) and 1.54 (3H, d, J = 22.0 Hz).
Determination of the stereochemistry was based on a NOE correlation of
4. Poynard, T.; Yuen, M.-F.; Ratziu, V.; Lai, C. L. Lancet 2003, 362, 2095.
5. For a review of anti-HIV and anti-HCV drugs, see: De Clercq, E. Nat. Rev. Drug
Disc. 2007, 6, 1001.
6. Carroll, S. S.; Tomassini, J. E.; Bosserman, M.; Getty, K.; Stahlhut, M. W.; Eldrup,
A. B.; Bhat, B.; Hall, D.; Simcoe, A. L.; LaFemina, R.; Rutkowski, C. A.; Wolanski,
B.; Yang, Z.; Migliaccio, G.; Francesco, R. D.; Kuo, L. C.; MacCoss, M.; Olsen, D. B.
J. Biol. Chem. 2003, 278, 11979.
7. Eldrup, A. B.; Prhavc, M.; Brooks, J.; Bhat, B.; Prakash, T. P.; Song, Q.; Bera, S.;
Bhat, N.; Dande, P.; Cook, P. D.; Bennett, C. F.; Carroll, S. S.; Ball, R. G.;
Bosserman, M.; Burlein, C.; Colwell, L. F.; Fay, J. F.; Flores, O. A.; Getty, K.;
LaFemina, R. L.; Leone, J.; MacCoss, M.; McMasters, D. R.; Tomassini, J. E.;
Langen, D. V.; Wolanski, B.; Olsen, D. B. J. Med. Chem. 2004, 47, 5284.
8. Clark, J. L.; Hollecker, L.; Mason, J. C.; Stuyver, L. J.; Tharnish, P. M.; Lostia, S.;
McBrayer, T. R.; Schinazi, R. F.; Watanabe, K. A.; Otto, M. J.; Furman, P. A.; Stec,
W. J.; Patterson, S. E.; Pankiewicz, K. W. J. Med. Chem. 2005, 48, 5504.
9. Wang, P.; Chun, B.-K.; Rachakonda, S.; Du, J.; Khan, N.; Shi, J.; Stec, W.; Cleary,
D.; Ross, B. S.; Sofia, M. J. J. Org. Chem. 2009, 74, 6819.
ribofuranose H-10 with H-30 in the
a anomer.
13. 1H NMR (300 MHz, DMSO-d6) 8.10 (1H, s, H-2), 7.44 (1H, d, J = 1.8 Hz, H-6),
7.09 (2H, br s, NH2), 6.37 (1H, d, J = 17.9 Hz, H-10), 5.61 (1H, d, J = 6.9 Hz,
30-OH), 5.25 (1H, t, J = 4.8 Hz, 50-OH), 4.06 (1H, ddd, J = 26.0, 9.5, 7.7 Hz, H-30),
3.88–3.38 (3H, m, H-40 and H-50) and 0.94 (3H, d, J = 22.3 Hz, CH3); 13C NMR
(DMSO-d6) 155.9 (C-4), 153.1 (C-2), 145.8 (C-8), 142.8 (C-5, d, JFC = 245.7 Hz),
103.4 (C-6, d, JFC = 26.3 Hz), 101.3 (C-20, d, JFC = 179.9 Hz), 92.1 (C-9,
d, JFC = 16.6 Hz), 87.2 (C-10, d, JFC = 38.8 Hz), 81.7 (C-40), 70.4 (C-30, d, JFC
17.3 Hz), 59.0 (C-50) and 16.1 (CH3, d, JFC = 25.6 Hz); Found: M++H, 301.1150.
12H15F2N4O3 requires 301.1112.
=
C
14. (a) Hwang, D.-R.; Lai, H.-Y.; Chang, M.-L.; Hsu, J. T.; Yeh, C.-T. J. Virol. Methods
2005, 129, 170; (b) Hwang, D.-R.; Tsai, Y.-C.; Lee, J.-C.; Huang, K.-K.; Lin, R.-K.;
Ho, C.-H.; Chiou, J.-M.; Lin, Y.-T.; Hus, J. T.; Yeh, C.-T. Antimicrob. Agents
Chemother. 2004, 48, 2876; (c) Yeh, C.-T.; Hwang, D.-R.; Lai, H.-Y.; Hsu, J. T.
Biochem. Biophys. Res. Commun. 2003, 310, 537; (d) Yeh, C.-T.; Lai, H.-Y.; Chen,
T.-C.; Chu, C.-M.; Liaw, Y.-F. J. Virol. 2001, 75, 11017.