A compound of the formula I: ** Formula ** or a pharmaceutically acceptable salt thereof, wherein: Z1 is C, and L is a divalent residue selected from the group consisting of -N (H) - and -C (H) - (R1) -, or Z1 is N, and L is CH2； R1 is hydrogen, hydroxyl, or amino； Z2 is C (R2) or N； Z3 is C or N, Z4 is C (R4) or N； Z5 is C (R5) or N, or an N-oxide thereof； Z6 is C (R6) or N, or an N-oxide thereof； Z7 is C (R7) or N, or an N-oxide thereof； Z8 is C or N； Z9 is C or N； wherein one of Z1, Z3, Z8 and Z9 is N, and three of Z1, Z3, Z8 and Z9 are C； wherein 0, 1 or 2 or 3 of Z2, Z4, Z5, Z6 and Z7 are N； R2 is hydrogen or alkyl of 1 to 6 carbon atoms； R3 is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, hydroxy alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms-alkyl of 1 to 4 carbon atoms, halo-alkyl of 1 to 4 carbon atoms, amino, or methyl amino； R4 is selected from the group consisting of hydrogen, halogen, and alkyl of 1 to 6 carbon atoms； R5 and R6 are independently selected from the group consisting of hydrogen, halogen, hydroxyl, NR8R9, cyano, CO2H, CONR10R11, SO2alkyl of 1 to 6 carbon atoms, SO2NH2, SO2NR10R11, alkoxy of 1 to 6 carbon-carbon atoms , -C (NR10) NR8R9, alkyl of 1 to 6 carbon atoms, halo-alkyl of 1 to 6 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, halo-alkoxy of 1 to 6 carbon atoms, and alkenyloxy of 2 to 6 carbon atoms, wherein each alkyl, alkenyl, alkoxy and alkenyloxy is unsubstituted or substituted with up to 4 substituents independently selected from halogen, hydroxyl, cyano, tetrazole, alkoxy of 1 to 4 carbon atoms, haloalkoxy of 1 to 4 carbon atoms, CO2H, alkoxy of 1 to 6 carbon atoms-carbonyl, C (O) NR10R11, NR8R9, optionally substituted phenyl, optionally substituted heterocycle having 4 at 7 ring atoms and 1, 2, or 3 heteroatoms of the ring selected from N, O or S, optionally substituted heteroaryl having 5 or 6 ring atoms and 1, 2 or 3 ring heteroatoms selected from N, O
