Inhibitors of the renal outer medullary potassium channel

A compound having structural Formula I:

• and the pharmaceutically acceptable salts thereof wherein:
• represents
• Z1 is
• Z2 is selected from the group consisting of:
• X is selected from the group consisting of —H, —OH, —OC1-3alkyl, —F, oxo, NH2, and —CH3;
• Y is selected from the group consisting of —H, —OH, —OC1-3alkyl, —F, oxo, NH2, and —CH3;
• X1 and Y1 are each independently selected from the group consisting of —H and —CH3;
• Y2 is —O—;
• provided that when X is oxo then X1 is absent and when Y is oxo then Y1 is absent;
• and further provided that when Z2 is z2-i, z2-ii, z2-iii, z2-iv, z2-ix or z2-x, then at least one of X and Y is selected from the group consisting of —OH, —OC1-3alkyl, —F and oxo, and when Z2 is z2-v or z2-vii, then X is selected from the group consisting of —OH, —OC1-3alkyl, —F and oxo;
• R1 and R2 are each independently selected from the group consisting of —H, -halo, —C3-C6cycloalkyl, —OR8, —SR8, —SOR8, —SO2R8, —(CH2)nOR8 and C1-C6alkyl optionally substituted with 1-3 of —F;
• one of R4a and R4b is selected from the group consisting of —CN and —NO2 and the other is Rf;
• R5 and R6 are each independently selected from the group consisting of —H, —C1-6 alkyl, —C3-6 cycloalkyl, —CF3, —CHF2, —CH2F and —CH2OH;
• R7 is selected from the group consisting of —H, —CH3, —CF3, —CHF2, —CH2F and —CH2OH;
• Rb is selected from the group consisting of (a) —H, (b) halo, (c) —C1-6 alkyl optionally substituted with 1-3 of —F, (d) —C3-6 cycloalkyl, (e) —OC1-3alkyl optionally substituted with 1-3 of —F, (f) —OR8, (g) —CO2C1-6alkyl optionally substituted with 1-3 of —F, (h) —(CH2)nOR8, (i) —SR8, (j) —SOR8, (k) —SO2R8, (l) —NHCOR8 and (m) —NHSO2R8;
• Rc and Rd are each independently selected from the group consisting of (a) —H, (b) halo, (c) —C1-6 alkyl optionally substituted with 1-3 of —F, (d) —C3-6 cycloalkyl, (e) —OC1-3alkyl optionally substituted with 1-3 of —F, (f) —OR8, (g) —CO2C1-6alkyl optionally substituted with 1-3 of —F, (h) —(CH2)nOR8, (i) —SR8, (j) —SOR8, (k) —SO2R8, (l) —NHCOR8 and (m) —NHSO2R8;
• Rf is selected from the group consisting of (a) —H, (b) halo, (c) —C1-6 alkyl optionally substituted with 1-3 of —F, (d) —C3-6 cycloalkyl, (e) —OC1-3alkyl optionally substituted with 1-3 of —F, (f) —OR8, (g) —CO2C1-6alkyl optionally substituted with 1-3 of —F, (h) —(CH2)nOR8, (i) —SR8, (j) —SOR8, (k) —SO2R8, (l) —NHCOR8 and (m) —NHSO2R8;
• n is an integer selected from 1, 2 and 3;
• and
• R8 is independently selected at each occurrence from the group consisting of —H, —C3-6cycloalkyl and —C1-6alkyl optionally substituted with 1-3 of —F.