A compound of formula I: ** Formula ** wherein Y is -L-R1 or a heterocyclyl or heteroaryl ring attached through a ring nitrogen atom, in which each heterocyclyl or heteroaryl is optionally substituted with 1 to 3 groups independently selected from the group consisting of C1-C6 alkyl, C3-C6 cycloalkyl, halo, aryl, heterocyclyl, heteroaryl, oxo, C1-C6 alkoxy, -OH, -NH2, -COR7, -CO2R7, -NHSO2R7 , -NHCO2R7 and -CN； and wherein each C1-C6 alkyl, C3-C6 cycloalkyl, aryl, heterocyclyl, heteroaryl and C1-C6 alkoxy optionally is substituted with 1 to 3 C1-C6 alkoxy, halo, -CF3, -CN, -OH, - NH2 or -OCF3； X is CR8 or N； Z is CR9 or N； L is -O-, -NR5-, -NR5 (CHR6) n-, -O (CHR6) n, -O (CHR6) nC (O) -, -O (CHR6) nC (O) O-, -O (CHR6) nNH-, - O (CHR6) nC (O) NH-, -O (CHR6) nNHC (O) O- or -O (CHR6) mNHS (O) 2-； R1 is hydrogen, C1-C6 alkyl, C3-C8 cycloalkyl, aryl, heterocyclyl or heteroaryl； wherein each cycloalkyl, aryl, heterocyclyl or heteroaryl is optionally substituted with 1 to 3 groups independently selected from the group consisting of C1-C6 alkyl, C3-C6 cycloalkyl, halo, aryl, heterocyclyl, heteroaryl, oxo, -OH , -NH2, -COR7, -CO2R7, -NHSO2R7, -NHCO2R7 and -CN； and wherein each C1-C6 alkyl, C3-C6 cycloalkyl, aryl, heterocyclyl and heteroaryl is optionally substituted with 1 to 3 C1-C6 alkoxy, halo, - CF3, -CN, -OH, -NH2 or -OCF3； each R2 is independently halo, C1-C6 alkyl, C1-C6 alkoxy or -OCF3； R3 is hydrogen, halo, C1-C3 haloalkyl, C1-C3 haloalkoxy, C3-C6 cycloalkyl or phenyl, wherein the cycloalkyl or phenyl are optionally substituted with one or two halogen atoms, with the proviso that when R3 is hydrogen, p 1 or 2； each R4 is independently C1-C6 alkyl, halo, C1-C6 alkoxy or -OCF3； or R3 and R4 together with the carbon atoms to which they are attached form a C4-C8 ring that optionally contains one to 30 three double bonds and optionally contains one to three heteroatoms independently selected from the group that it consists of O, N and S, a ring which may be substituted,
