Compounds of formula wherein X is selected from i) N, and ii) CH; Y is selected from i) N, and ii) CR 10; Z is selected from i) N, and ii) CR 11; R 1 is selected from i) C 1-6 -alkyl, ii) halo-C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) halo-C 1-6 -alkoxy, v) hydroxy-C 1-6 -alkyl, vi) C 3-8 -cycloalkyl, vii) halogen, and viii) amino substituted on the nitrogen atom by one or two substituents independently selected from a. H, b. C 1-6 -alkyl, and c. C 3-8 -cycloalkyl; R 2 is selected from i) H, and i) halogen; R 3 is selected from i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl, iii) hydroxy-C 1-6 -alkyl, and iv) halo-C 1-6 -alkyl; R 4 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; R 5 is H; R 6 is selected from i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl substituted with R 7, R 8 and R 9, iii) C 3-8 -cycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9, iv) C 1-6 -alkylsulfonyl-C 1-6 -alkyl, v) cyano-C 1-6 -alkyl, vi) hydroxy-C 1-6 -alkyl, vii) dihydroxy-C 1-6 -alkyl, viii) halo-C 1-6 -alkyl, ix) heterocycloalkyl substituted with R 7, R 8 and R 9, and x) heterocycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9; R 7, R 8 and R 9 are independently selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 1-6 -alkoxyalkyl, v) C 1-6 -alkoxycarbonyl, vi) cyano, vii) C 3-8 -cycloalkoxy, viii) C 3-8 -cycloalkyl, ix) halo-C 1-6 -alkoxy, x) halo-C 1-6 -alkyl, xi) halogen, xii) hydroxy, xiii) hydroxy-C 1-6 -alkyl, and xiv) oxo; R 10 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; R 11 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; or R 5 and R 10 together form -(CH 2) n -; or R 5 and R 11 together form -(CH 2) n -; or R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocycloalkyl substituted with R 7, R 8 and R 9; n is selected from 1 and 2; or pharmaceutically acceptable salts. X is selected from i) N, and ii) CH; i) N, and ii) CH; Y is selected from i) N, and ii) CR 10; i) N, and ii) CR 10; Z is selected from i) N, and ii) CR 11; i) N, and ii) CR 11; R 1 is selected from i) C 1-6 -alkyl, ii) halo-C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) halo-C 1-6 -alkoxy, v) hydroxy-C 1-6 -alkyl, vi) C 3-8 -cycloalkyl, vii) halogen, and viii) amino substituted on the nitrogen atom by one or two substituents independently selected from a. H, b. C 1-6 -alkyl, and c. C 3-8 -cycloalkyl; i) C 1-6 -alkyl, ii) halo-C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) halo-C 1-6 -alkoxy, v) hydroxy-C 1-6 -alkyl, vi) C 3-8 -cycloalkyl, vii) halogen, and viii) amino substituted on the nitrogen atom by one or two substituents independently selected from a. H, b. C 1-6 -alkyl, and c. C 3-8 -cycloalkyl; a. H, b. C 1-6 -alkyl, and c. C 3-8 -cycloalkyl; R 2 is selected from i) H, and i) halogen; i) H, and i) halogen; R 3 is selected from i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl, iii) hydroxy-C 1-6 -alkyl, and iv) halo-C 1-6 -alkyl; i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl, iii) hydroxy-C 1-6 -alkyl, and iv) halo-C 1-6 -alkyl; R 4 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; R 5 is H; R 6 is selected from i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl substituted with R 7, R 8 and R 9, iii) C 3-8 -cycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9, iv) C 1-6 -alkylsulfonyl-C 1-6 -alkyl, v) cyano-C 1-6 -alkyl, vi) hydroxy-C 1-6 -alkyl, vii) dihydroxy-C 1-6 -alkyl, viii) halo-C 1-6 -alkyl, ix) heterocycloalkyl substituted with R 7, R 8 and R 9, and x) heterocycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9; i) H, i) C 1-6 -alkyl, ii) C 3-8 -cycloalkyl substituted with R 7, R 8 and R 9, iii) C 3-8 -cycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9, iv) C 1-6 -alkylsulfonyl-C 1-6 -alkyl, v) cyano-C 1-6 -alkyl, vi) hydroxy-C 1-6 -alkyl, vii) dihydroxy-C 1-6 -alkyl, viii) halo-C 1-6 -alkyl, ix) heterocycloalkyl substituted with R 7, R 8 and R 9, and x) heterocycloalkyl-C 1-6 -alkyl substituted with R 7, R 8 and R 9; R 7, R 8 and R 9 are independently selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 1-6 -alkoxyalkyl, v) C 1-6 -alkoxycarbonyl, vi) cyano, vii) C 3-8 -cycloalkoxy, viii) C 3-8 -cycloalkyl, ix) halo-C 1-6 -alkoxy, x) halo-C 1-6 -alkyl, xi) halogen, xii) hydroxy, xiii) hydroxy-C 1-6 -alkyl, and xiv) oxo; i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 1-6 -alkoxyalkyl, v) C 1-6 -alkoxycarbonyl, vi) cyano, vii) C 3-8 -cycloalkoxy, viii) C 3-8 -cycloalkyl, ix) halo-C 1-6 -alkoxy, x) halo-C 1-6 -alkyl, xi) halogen, xii) hydroxy, xiii) hydroxy-C 1-6 -alkyl, and xiv) oxo; R 10 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; R 11 is selected from i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; i) H, ii) C 1-6 -alkyl, iii) C 1-6 -alkoxy, iv) C 3-8 -cycloalkyl, and v) halogen; or R 5 and R 10 together form -(CH 2) n -; or R 5 and R 11 together form -(CH 2) n -; or R 5 and R 6 together with the nitrogen atom to which they are attached form a heterocycloalkyl substituted with R 7, R 8 and R 9; n is selected from 1 and 2; or pharmaceutically acceptable salts.