Patent ID: 7164021

Claim:
A composition of matter comprising: wherein R 1 is O, NH, NR 6 , S, SH, or SR 6 ; R 2 is H, ═O, t-butyl, phenoxy, diphenylamine, thiophenyl, phenyl, or cyclohexane; R 3 is phenoxy; wherein R 2 and R 3 comprise a ring system selected from: or wherein R 3 and R 4 comprise a ring system selected from: or R 4 is H or t-butyl; and R 5 is CH 3 , methylcyclopropane, a linear alkyl, a branched alkyl, a substituted alkyl, or a substituted branched alkyl; R 6 is H, CH 3 , a linear alkyl, a branched alkyl, a substituted alkyl, or a substituted branched alkyl; or a pharmaceutically acceptable salt thereof.