Monobactams

A compound of Formula (I):

• or a pharmaceutically acceptable salt thereof,
• wherein
• R1 and R2 are each independently hydrogen, optionally substituted (C1-C6)alkyl, or phenyl(C1-C6)alkyl wherein the phenyl and the (C1-C6)alkyl moieties of the phenyl(C1-C6)alkyl are optionally substituted;
• or
• R1 and R2 together, with the carbon atom to which they are attached, form an optionally substituted (C3-C6)cycloalkyl or an optionally substituted 4-6-membered heterocycle;
• E is C(H), C(F), C(Cl), or N;
• X is —O—C(═O)—, —NH—C(═O)—, —NH—SO2—, —NH—C(═N—CN)—, —NH-T-, or triazole;
• L is absent, —(CH2)p—, —(CH2)p—NH—(CH2)q, —(CH2)p—O—(CH2)q—, —(CH2)p—C(═O)—NH—(CH2)q—, —(CH2)p—NH—C(═O)—(CH2)q—, —CH(CH3)—NH—C(═O)—(CH2)q—, —(CH2)p—NH—C(═O)—NH—(CH2)q—, —CH(CH3)—NH—C(═O)—NH—(CH2)q—, —(CH2)p-T-SO2—NH—(CH2)q—, —(CH2)p-T-(CH2)q, —(CH2)p-T-C(═O)—NH—(CH2)q—, —(CH2)p-T-(CH2)q—NH—C(═O)—, —NH—(CH2)p-T-, —O—(CH2)p-T-, —(CH2)p—Y—C(═O)—(CH2)q—, or —(CH2)p—Y—(CH2)q—;
• T is an optionally substituted phenyl or an optionally substituted 5- or 6-membered heteroaryl;
• Y is an optionally substituted 4-6 membered heterocycle;
• p and q are each independently 0, 1, 2, or 3;
• A is
• and
• R3 is hydrogen, (C1-C3)alkyl, or OH;
• provided that Formula (I) does not include 2-(((1-(2-aminothiazol-4-yl)-2-(((2S,3R)-2-((3-((1,5-dihydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl)ureido)methyl)-4-oxo-1-sulfoazetidin-3-yl)amino)-2-oxoethylidene)amino)oxy)-2-methylpropanoic acid.