Patent ID: 8114997

Claim:
A compound of formula (II): or a pharmaceutically acceptable salt thereof, wherein X is S, NR 5 , CH 2 , CHF or CF 2 ; R 1 is chosen from halogen, alkyl, haloalkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, cycloalkyl, CN, CF 3 , N 3 , NO 2 , aryl, heteroaryl and acyl; R 2 is chosen from alkenyl, alkynyl, cycloalkyl, aminoalkyl, hydroxyalkyl, haloalkyl, thioalkyl, heteroaryl, and C 6 H 4 R 6 where R 6 is chosen from halogen, CN, CF 3 , N 3 , alkyl, haloalkyl, aminoalkyl, alkoxy, thioalkyl, alkenyl, alkynyl, and aryl; R 3 and R 3′ are chosen independently from H, halogen, CN, CF 3 , N 3 , NO 2 , alkyl, alkenyl, and alkynyl; R 4 is H, phosphate, carbonyl substituted with alkyl, alkenyl, alkynyl, or aryl; and R 5 is H, acyl, alkyl, alkenyl, alkynyl, or cycloalkyl.