5-Aza-7-deazapurine derivatives for treating Flaviviridae

A method of treating a host infected with a flavivirus or pestivirus, comprising administering an effective amount of a biologically active compound to a host in need thereof, wherein the biologically active compound has the structure of Formulae (i), (ii), (iii), (iv), (v) or (vi):

• or a pharmaceutically acceptable salt or prodrug thereof, wherein:
• A, B and Y, each independently, is H;
• halogen;
• OR′, S(O)n;
• S(O)nR′;
• S(O)nR′R″;
• NR′R″;
• NR;
• CN;
• CF3;
• CR′R″;
• C(═W)OR′;
• C(═W)SR′;
• C(═W)NR′R′;
• C1-4 alkylamino;
• di(C1-4 alkyl)amino;
• C3-6 cycloalkylamino;
• NO2;
• N3;
• C1-10 cyclic or acyclic, branched or unbranched alkyl, alkenyl, alkynyl;
• aryl;
• aralkyl;
• heterocycle;
• or A and B taken together with the carbon atoms to which they are attached may form a 4-7 membered carbocyclic or heterocyclic ring;
• Z is O, S, NR′, or CR′R″;
• each V is independently N or CR′;
• each R′ and R″ independently is H;
• C1-10 cyclic or acyclic, branched or unbranched alkyl, alkenyl, alkynyl;
• halo;
• O-alkyl;
• NH2;
• NHMe;
• N(Me)2;
• CN;
• acyl;
• aryl;
• heteroaryl;
• heterocycle;
• carbocycle;
• amino acid residue;
• or together with the atoms to which they are attached may form a 3-7 membered carbocyclic or heterocyclic ring;
• each W is independently O, S, or NR′;
• each R is independently H;
• C1-10 cyclic or acyclic, branched or unbranched alkyl, alkenyl, alkynyl, acyl, aryl, or aralkyl, any of which optionally may have one or more heteroatoms and any of which may be taken alone or in combination with one another;
• 3-7 membered carbocycle or heterocycle;
• or a functional group that dissociates to provide the base where R is H;
• each n is independently 0, 1 or 2;
• wherein any branched or unbranched, cyclic or acyclic alkyl, alkenyl, or alkynyl may optionally comprise at least one heteroatom selected from the group consisting of O, S, N and P;
• wherein any branched or unbranched, cyclic or acyclic alkyl, alkenyl, alkynyl;
• aryl;
• acyl;
• or aralkyl may optionally be substituted with one or more of OR′, SR′, NR′R″, halogen, NO2, CN, N3, CF3, C(═W)OR′, C(═W)NR′R″, C(═W)SR′, alkyl, alkenyl, alkynyl, aryl, aralkyl, acyl, heterocycle or heteroatom selected from the group consisting of O, S, N and P;
• and
• all tautomeric, enantiomeric and stereoisomeric forms thereof,
• with the caveat that in Formula (i), when A and B are both H, both Vs are N, Z is O, and Y is —NH2, then Formula (i) is not β-D-2′-deoxy-5-aza-7-deazaguanosine, β-D-5-aza-7-deazaguanosine, β-D-5′-methyl-5-aza-7-deazaguanosine, or 2-amino-8-(methyl-pivalate)imidazo[1,2-a]-s-triazin-4-one.