Nucleoside compounds for treating viral infections

1. A compound of formula I:

wherein:

Y is O or CH 2 ;

X is selected from halo and O—W 2 ;

each of W, W 1 and W 2 is independently selected from the group consisting of hydrogen, C 1 -C 4 alkyl, acyl, oxyacyl, phosphonate, phosphate esters, phosphate, phosphonamidate, phosphorodiamidate, phosphoramidate monoester, cyclic phosphoramidate, cyclic phosphorodiamidate, and phosphoramidate diester, provided that when X is —O—W 2 , one of W, W 1 and W 2 is C 1 -C 4 alkyl;

R 3 is selected from the group consisting of hydrogen, OH, acyl, C 1 -C 4 alkyl, and C 1 -C 4 alkoxy;

T is selected from the group consisting of:

a) —C≡C—R, where R is selected from the group consisting of:

i) hydrogen;

ii) tri(C 1 -C 4 )alkylsilyl, —C(O)NR 1 R 2 , alkoxyalkyl, heteroaryl, substituted heteroaryl, phenyl, and substituted phenyl;

where R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, amino, substituted amino, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substituted heterocyclic provided that only one of R 1 and R 2 is amino or substituted amino, and further wherein R 1 and R 2 , together with the nitrogen atom pendant thereto, form a heterocyclic or substituted heterocyclic; and

iii) —C(O)OR 14 , where R 14 is hydrogen, alkyl or substituted alkyl;

b) —CH═CH-Q 2 , where Q 2 is selected from hydrogen or cis-alkoxy;

c) —C(O)H;

d) —CH═NNHR 15 , where R 15 is hydrogen or C 1 -C 4 alkyl;

e) —CH═N(OR 15 ), where R 15 is as defined above;

f) —CH(OR 16 ) 2 , where R 16 is C 3 -C 6 alkyl;

g) —B(OR 15 ) 2 , where R 15 is as defined above; and

h) —NO 2 ;

or pharmaceutically acceptable salts or partial salts thereof;

provided that when R 3 is hydrogen, OH, or C 1 -C 3 alkoxy, then X is halo or —O(C 1 -C 4 alkyl).

2. The compound according to claim 1 , wherein X is halo.

3. The compound according to claim 2 , wherein X is fluoro.

4. The compound according to claim 2 , wherein T is —C≡C—R and R is hydrogen.

5. The compound according to claim 2 , wherein T is —C≡C—R and R is selected from the group consisting of tri(C 1 -C 4 )alkylsilyl, —C(O)NR 1 R 2 , alkoxyalkyl, heteroaryl, substituted heteroaryl, phenyl, and substituted phenyl.

6. The compound according to claim 5 , wherein R is selected from the group consisting of phenyl, —C(O)NH 2 , —Si(CH 3 ) 3 , pyrid-2-yl, 4-methoxyphenyl, and —CH(OCH 2 CH 3 ) 2 .

7. The compound according to claim 2 , wherein T is —C≡C—R and R is —C(O)OH.

8. The compound according to claim 2 , wherein T is —C≡C—R, R is —C(O)OR 14 , and R 14 is alkyl.

9. The compound according to claim 2 , wherein T is —CH═CH-Q 2 , where Q 2 is selected from hydrogen or cis-methoxy.

10. The compound according to claim 2 , wherein T is —C(═O)H.

11. The compound according to claim 2 , wherein T is —CH═NNHR 15 .

12. The compound according to claim 2 , wherein T is —CH═N(OR 15 ).

13. The compound according to claim 2 , wherein T is —CH(OR 16 ) 2 .

14. The compound according to claim 2 , wherein T is —B(OR 15 ) 2 .

15. The compound according to claim 2 , wherein T is NO 2 .

16. The compound according to claim 2 , wherein R 3 is hydrogen.

17. The compound according to claim 1 , wherein X is O—W 2 , and W 2 is C 1 -C 4 alkyl.

18. The compound according to claim 17 , wherein W 2 is methyl.

19. A compound of claim 1 having formula Ib:

wherein:

X″ is halo;

each of W and W 1 , is independently selected from the group consisting hydrogen of acyl, oxyacyl, phosphonate, phosphate esters, phosphate, phosphonamidate, phosphorodiamidate, phosphoramidate monoester, cyclic phosphoramidate, cyclic phosphorodiamidate, phosphoramidate diester, and —C(O)CHR 30 NHR 31 where R 30 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl and substituted heteroaryl and R 31 is hydrogen or R 30 together with the carbon atom pendent thereto and R 31 together with the nitrogen atom pendent thereto join to form a heterocyclic or substituted heterocyclic ring;

R 3 is selected from the group consisting of hydrogen, OH, acyl, C 1 -C 4 alkyl, and C 1 -C 4 alkoxy;

T is selected from the group consisting of:

a) —C≡C—R, where R is selected from the group consisting of

i) hydrogen;

ii) tri(C 1 -C 4 )alkylsilyl, —C(O)NR 1 R 2 , alkoxyalkyl, heteroaryl, substituted heteroaryl, phenyl, and substituted phenyl;

where R 1 and R 2 are independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, amino, substituted amino, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocyclic and substituted heterocyclic provided that only one of R 1 and R 2 is amino or substituted amino, and further wherein R 1 and R 2 , together with the nitrogen atom pendant thereto, form a heterocyclic or substituted heterocyclic;

iii) —C(O)OR 14 , where R 14 is hydrogen, alkyl or substituted alkyl;

b) —CH═CH-Q 2 , where Q 2 is selected from hydrogen or cis-alkoxy;

c) —C(O)H;

d) —CH═NNHR 15 , where R 15 is hydrogen or C 1 -C 4 alkyl;

e) —CH═N(OR 15 ), where R 15 is as defined above;

f) —CH(OR 16 ) 2 , where R 16 is C 3 -C 6 alkyl;

g) —B(OR 15 ) 2 , where R 15 is as defined above; and

h) —NO 2 ;

or pharmaceutically acceptable salts thereof.

20. The compound according to claim 19 wherein X″ is fluoro.

21. The compound according to claim 19 , wherein T is —C≡C—R and R is hydrogen.

22. The compound according to claim 19 , wherein T is —C≡C—R and R is selected from the group consisting of tri(C 1 -C 4 )alkylsilyl, —C(O)NR 1 R 2 , alkoxyalkyl, heteroaryl, substituted heteroaryl, phenyl, and substituted phenyl.

23. The compound according to claim 22 , wherein R is selected from the group consisting of phenyl, —C(O)NH 2 , —Si(CH 3 ) 3 , pyrid-2-yl, 4-methoxyphenyl, and —CH(OCH 2 CH 3 ) 2 .

24. The compound according to claim 19 , wherein T is —C≡C—R and R is —C(O)OH.

25. The compound according to claim 19 , wherein T is —C≡C—R, R is —C(O)OR 14 , and R 14 is alkyl.

26. The compound according to claim 19 , wherein T is —CH═CH-Q 2 , where Q 2 is selected from hydrogen or cis-methoxy.

27. The compound according to claim 19 , wherein T is —C(═O)H.

28. The compound according to claim 19 , wherein T is —CH═NNHR 15 .

29. The compound according to claim 19 , wherein T is —CH═N(OR 15 ).

30. The compound according to claim 19 , wherein T is —CH(OR 16 ) 2 .

31. The compound according to claim 19 , wherein T is —BC(OR 15 ) 2 .

32. The compound according to claim 19 , wherein T is NO 2 .

33. The compound according to claim 19 , wherein R 30 , optionally together with R 31 , is a sidechain of an amino acid.

34. The compound according to claim 33 , wherein R 30 , optionally together with R 31 , is a sidechain of an L-amino acid.

35. The compound according to claim 19 , wherein at least one of W or W 1 is hydrogen.

36. The compound according to claim 35 , wherein both W and W 1 are hydrogen.

37. The compound according to claim 19 , wherein one of W and W 1 is hydrogen, and the other of W and W 1 is represented by the formula:

wherein R 31 is hydrogen, R 30 is a sidechain of an amino acid, or R 30 and R 31 together form the side chain of an amino acid, R 8 is hydrogen or alkyl, and R 10 is selected from the group consisting of alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, substituted cycloalkyl, heteroaryl, substituted heteroaryl, heterocyclic and substituted heterocyclic.

38. The compound according to claim 37 wherein R 30 , optionally together with R 31 , is a sidechain of an L-amino acid.

39. The compound according to claim 19 , wherein one of W and W 1 is hydrogen, and the other of W and W 1 is represented by the formula:

where R 31 is hydrogen and R 30 , optionally together with R 31 , is a side chain of an amino acid.

40. The compound according to claim 39 , wherein R 30 , optionally together with R 31 , is a sidechain of an L-amino acid.

41. The compound according to claim 19 , wherein R 3 is hydrogen.

42. The compound according to claim 1 selected from the group consisting of:

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine;7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofaranosyl)-4-hydroxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-fluoro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-chloro-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-methylhydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-bromo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxyo-2′-C-methyl-β-D-ribofuranosyl)-4-amino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofaranosyl)-4-hydroxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxyo-2′-C-methyl-β-D-ribofuranosyl)-4-hydroxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxyo-2′-C-methyl-β-D-ribofuranosyl)-4-acetylamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-nitro-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(phenylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-formyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-boronic acid-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-acetylenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(trimethylsilylacetylenyl)-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-ethenyl-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxy-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-methylenehydrazine-pyrrolo[2,3-d]pyrimidine;

7-(2′-deoxy-2′-methoxyo-2′-C-methyl-β-D-ribofuranosyl)-4-ethoxyamino-5-(carbaldehyde-oxime)-pyrrolo[2,3-d]pyrimidine;

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-triphosphate;

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Rp/Sp-Methoxyalaninylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-L-valyl ester;

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Bis(S-pivaloyl-2-thioethyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Bis(S-(3-methyl-butyryl)-2-thioethyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyalaninyl-(4-methoxyphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyalaninyl-(4-fluorophenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Ethoxyalaninylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyalaninyl-(4-methylphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyalaninyl-(4-propylphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxyalaninyl-phenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxyalaninyl-(naphthalen-2-yl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxyalaninyl-(naphthalen-1-yl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxyalaninyl-(4-chloro-naphthalen-1-yl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxyalaninyl-(4-methoxy-naphthalen-1-yl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyphenylalaninylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyphenylalaninyl-(4-methoxyphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyphenylalaninyl-(4-fluorophenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyphenylalaninyl-(4-methylphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyvalinylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyvalinyl-(4-methoxyphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyvalinyl-(4-fluorophenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxyvalinyl-(4-methylphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy(dimethylglycyl)phenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Benzyloxy-dimethylglycinylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-dimethylglycinyl(4-fluorophenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-dimethylglycinyl(4-methoxyphenyl)phosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-dimethylglycinylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-prolinylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Bezyloxy-prolinylphenylphosphate];

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-prolinyl(4-fluorophenyl)phenylphosphate]; and

[4-Amino-5-ethynyl-7-(2-deoxy-2-fluoro-2-C-methyl-β-D-ribofuanosyl)-7H-pyrrolo[2,3-d]pyrimidine]5′-[Methoxy-prolinyl(4-methoxyphenyl)phenylphosphate].

43. A pharmaceutical composition comprising a pharmaceutically acceptable diluent and a compound according to claim 1 or a mixture of two or more of such compounds.

44. A method for treating a viral infection in a mammal mediated at least in part by a virus in the Flaviviridae family of viruses which method comprises administering to a mammal that has been diagnosed with said viral infection a pharmaceutical composition according to claim 43 .

45. The method according to claim 44 , wherein said virus is hepatitis C virus.

46. The method according to claim 45 in combination with the administration of a therapeutically effective amount of one or more agents active against hepatitis C virus.

47. The method of claim 46 wherein said active agent against hepatitis C virus is an inhibitor of HCV proteases, HCV polymerase, HCV helicase, HCV NS4B protein, HCV entry, HCV assembly, HCV egress, HCV NS5A protein, or inosine 5′-monophosphate dehydrogenase.

48. The method of claim 47 wherein said agent active against hepatitis C virus is interferon-alpha or pegylated interferon-alpha alone or in combination with ribavirin or levovirin.