abstract |
Compound having the formula (6): ** Formula ** or a pharmaceutically acceptable salt thereof, wherein: in which X1, X2, X3 and X4 are selected from N and CR7; one of X5, X6, X7 and X8 is N and the others are CH; X9 is selected from N and CH; Z is selected from phenyl, pyrazinyl, pyridinyl, pyridazinyl and piperazinyl; wherein each of phenyl, pyrazinyl, pyridinyl, pyridazinyl or piperazinyl of Z is optionally substituted with an R6 group; R1, R2 and R3 are hydrogen; m is 1; R4 is selected from hydrogen, halogen, difluoromethyl, trifluoromethyl and methyl; R6 is selected from hydrogen, halogen and -C (O) R10; wherein R10 is methyl; and R7 is selected from hydrogen, halogen, cyano, methyl and trifluoromethyl. |