Patent ID: 8884011

Claim:
A purine phosphonate compound of formula (I) as follows: or pharmaceutically acceptable salt thereof; wherein: B is a base selected from the group consisting of adenine, xanthine, hypoxanthine, guanine, 8-bromoguanine, 8-chloroguanine, 8-aminoguanine, 8-hydrazinoguanine, 8-hydroxyguanine, 8-methylguanine, 8-thioguanine, 2-aminopurine, and 2,6-diaminopurine; R 1 is selected from the group consisting of a hydrogen atom, and a methyl, ethyl, hydroxymethyl, hydroxyethyl and C 1-6 haloalkyl group; R 3 is selected from the group consisting of a hydroxyl group or alkaline metal salt thereof, —OR 3A , a prodrug moiety, a linear or branched C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 heteroalkyl, C 2-8 heteroalkenyl or C 2-8 heteroalkenyl group, an amino acid residue, and an amine group R″HN, wherein R 3A represents C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 heteroalkyl, C 2-8 heteroalkenyl, C 2-8 heteroalkynyl, —P(═O)(OH) 2 or alkaline metal salt thereof, or —P(═O)(OH)OP(═O)(OH) 2 or alkaline metal salt thereof, and R″ is a linear or branched C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 heteroalkyl, C 2-8 heteroalkenyl, C 2-8 heteroalkynyl, or C 6-10 aryl group; and (a) X is selected from the group consisting of a selenium atom and a sulphur atom, and R 2 is selected from the group consisting of a fluorine atom, a hydroxyl group or alkaline metal salt thereof, —OR 2A , a prodrug moiety, BH 3 − , a linear or branched C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 1-8 heteroalkyl, C 2-8 heteroalkenyl or C 2-8 heteroalkynyl group, an amino acid residue, and an amine group R′HN wherein R 2A represents C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkenyl, C 1-8 heteroalkyl, C 2-8 heteroalkenyl, C 2-8 heteroalkenyl, —P(═O)(OH) 2 or alkaline metal salt thereof, —P(═O)(OH)OP(═O)(OH) 2 , or alkaline metal salt thereof, and R′ is a linear or branched C 1-8 heteroalkyl, C 2-8 heteroalkenyl, C 2-8 heteroalkynyl, or C 6-10 aryl; or (b) X represents an oxygen atom, and R 2 is selected from the group consisting of a fluorine atom and a BH 3 − group.