Purine monophosphate prodrugs for treatment of viral infections

A compound of Formula (A) or a compound of Formula (B):

• or a pharmaceutically acceptable salt or prodrug thereof, wherein:
• when chirality exists at the phosphorous center it may be wholly or partially Rp or Sp or any mixture thereof
• R1 is OH or F;
• Y is O or S;
• R24 is selected from OR15,
• and fatty alcohols,
• wherein R15, R17, and R18 are as defined below;
• R2 and R3, when administered in vivo, are capable of providing the nucleoside monophosphate or thiomonophosphate that is either partially or fully resistant to 6-NH2 deamination in a biological system and are independently selected from the group consisting of:
• (a) OR15 where R15 selected from H, Li, Na, K, phenyl and pyridinyl;
• Phenyl and pyridinyl are substituted with one to three substituents independently selected from the group consisting of (CH2)0-6CO2R16 and (CH2)0-6CON(R16)2;
• R16 is independently H, C1-20 alkyl, the carbon chain derived from a fatty alcohol or C1-20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, heteroaryl, substituted aryl, or substituted heteroaryl;
• wherein the substituents are C1-5 alkyl, or C1-5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, or cycloalkyl;
• (c) the ester of an L-amino acid
• where R17 is restricted to those occurring in natural L-amino acids, and R18 is H, C1-20 alkyl, the carbon chain derived from a fatty alcohol or C1-20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, heteroaryl, substituted aryl, or substituted heteroaryl;
• wherein the substituents are C1-5 alkyl, or C1-5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, or cycloalkyl;
• (d) R2 and R3 together to form a ring
• where R19 is H, C1-20 alkyl, C1-20 alkenyl, the carbon chain derived from a fatty alcohol or C1-20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, heteroaryl, substituted aryl, or substituted heteroaryl;
• wherein the substituents are C1-5 alkyl, or C1-5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, or cycloalkyl;
• and
• (e) R2 and R3 together to form a ring selected from
• where R20 is O or NH and
• R21 is selected from H, C1-20 alkyl, C1-20 alkenyl, the carbon chain derived from a fatty acid, and C1-20 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, cycloalkyl alkyl, cycloheteroalkyl, aryl, heteroaryl, substituted aryl, or substituted heteroaryl;
• wherein the substituents are C1-5 alkyl, or C1-5 alkyl substituted with a lower alkyl, alkoxy, di(lower alkyl)-amino, fluoro, C3-10 cycloalkyl, or cycloalkyl.