Antimicrobial compounds and methods

A compound of formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• Z is (C═O);
• ring A is selected from the group consisting of
• J is absent or is selected from the group consisting of —CH2—, —CH2CH2—,
• wherein each R3 is independently selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, halo, and C1-C6 haloalkyl, wherein m is 0, 1 or 2;
• Y is a linear C1-C8 alkylene optionally substituted with OH, NH2, CN, halo, C1-C6 alkyl, C1-C6 haloalkyl, COO(C1-C6 alkyl), COOH, CONH2, or C1-C6 alkoxy, and wherein up to two methylene units of the C1-C8alkylene are optionally and independently replaced by O, NH, N—(C1-C6 alkyl), N—(C1-C6 hydroxyalkyl), N—(C1-C6 haloalkyl), N—(C1-6 alkylene-C3-8 cycloalkyl), NH(C═O), N—(C1-6 alkyl)(C═O), or (C═O);
• ring B is a 5 to 12 membered fused, spiro, or bridged bicyclic heterocycloalkylene containing up to 3 nitrogen atoms, wherein the fused, spiro, or bridged bicyclic heterocycloalkylene is optionally substituted with up to three substituents independently selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, halo, C1-C6 haloalkyl, OH, and C1-C6 hydroxyalkyl;
• or
• ring B is a 5 to 12 membered fused, spiro, or bridged bicyclic cycloalkylene optionally substituted with up to two substituents selected from the group consisting of C1-C6 alkyl, C1-C6 alkoxy, halo, C1-C6 haloalkyl, OH, and C1-C6 hydroxyalkyl;
• L is absent, or is a linear or branched C1-C6 alkylene optionally substituted with C1-C6 alkoxy, halo, CN, OH, NH2, COO(C1-C6 alkyl), or CONH2, wherein one methylene unit of the C1-C6 alkylene may be replaced with O, NH, (C═O), or N—(C1-6 alkyl);
• R1 is H, NH2, NH(C1-C6 alkyl), NHCO(C1-C6 alkyl), or NH(C1-C6 alkyl-SO3−);
• R1′ is H, NH2, NH(C1-C6 alkyl), NHCO(C1-C6 alkyl), or NH(C1-C6 alkyl-SO3−);
• and
• R2 is independently selected from the group consisting of C1-C6 alkyl, halo, C1-C6 haloalkyl, O(C1-C6 haloalkyl), and C1-C6 alkoxy, and n is 0, 1, or 2.