Patent ID: 8895531

Claim:
A compound having a structure consistent with formula (1) or a pharmaceutically acceptable salt thereof, wherein: a) X is O, S, SO 2 , or CH 2 ; b) n is 1 or 2; c) R 1 is CH 3 ; d) R 2 and R 3 are independently a hydrogen, halogen, OH, OR′, SH, SR′, N 3 , NH 2 , NHR′, CN, OCOR′, OCOOR′, lower alkyl of C 1 -C 6 , halogenated lower alkyl of C 1 -C 6 , lower alkenyl of C 2 -C 6 , halogenated lower alkenyl of C 2 -C 6 , lower alkynyl of C 2 -C 6 , halogenated lower alkynyl of C 2 -C 6 , lower alkoxy of C 1 -C 6 lower alkyl acid of C 2 -C 6 , or lower alkyl acid ester of C 2 -C 6 ; e) each R′ is independently a hydrogen, lower alkyl of C 1 -C 6 , or lower cycloalkyl of C 1 -C 6 ; f) R 4 and R 5 are independently a hydrogen, phosphate, diphosphate, or analogs thereof wherein one or two hydrogens on a P(OH) moiety is replaced with an C 1-10 alkyl, aryl, amino acid ester, steroid, carbohydrate, or lipid group, wherein aryl groups are selected from the group consisting of phenyl, biphenyl, and naphthyl, optionally substituted with one or more moieties selected from the group consisting of hydroxyl, amino, alkylamino, arylamino, alkoxy, aryloxy, nitro, cyano, sulfonic acid, sulfate, phosphonic acid, phosphate, and phosphonate, and g) Base is a heterocycle containing at least one nitrogen.