Patent ID: 7772425

Claim:
A compound represented by formula I or a pharmaceutically acceptable salt thereof: wherein; R and R′ are independently methyl or ethyl; R 1 and R 2 are independently selected from hydrogen, halo, or C 1 -C 5 alkyl; Z B is a group represented by the formula: wherein -(L 1 )- is a bond or —(CH 2 ) m —O—; -(L 2 )- is a bond or —(CH 2 ) m —C(R40)(R40)-; -(L 3 )- is selected from the group consisting of wherein m is 0, 1, or 2, and each R40 is independently hydrogen or C 1 -C 5 alkyl; R B is a branched C 3 -C 5 alkyl; Z C is selected from: —C(O)OH, —C(O)O(C 1 -C 2 alkyl), —C(O)N(H)—CH 2 —C(O)OH, —C(O)N(H)—CH 2 —C(O)OC 1 -C 4 alkyl, —C(O)N(Me)-CH 2 —C(O)OH, —C(O)N(Me)-CH 2 —C(O)OC 1 -C 4 alkyl, —C(O)N(H)—CH(Me)-C(O)OH, —C(O)N(H)—CH(Me)-C(O)OC 1 -C 4 alkyl, —C(O)N(H)—CH(Et)-C(O)OH, —C(O)N(Me)-CH(Me)-C(O)OH, —C(O)N(H)—C(Me) 2 -C(O)OH, —C(O)N(H)—C(Me) 2 -C(O)OC 1 -C 4 alkyl, —C(O)N(Me)-C(Me) 2 -C(O)OH, C(O)NHSO 2 (C 1 -C 4 alkyl), —C(O)N(H)CH 2 CH 2 SO 2 Me, —CH 2 N(H)CH 2 CH 2 SO 2 CH 3 , —CH 2 CH 2 CO 2 H, —CH 2 CH 2 C(O)OC 1 -C 2 alkyl, —CH 2 CH 2 C (O)NH 2 , —CH 2 CH 2 C(O)NHMe, —CH 2 CH 2 C(O)NMe 2 , —CH═CHC(O)NMe 2 , —CH 2 —O—CH 2 C(O)OH, —CH 2 —O—CH 2 C(O)OC 1 -C 4 alkyl, -5-tetrazolyl, provided that the compound is not