A compound having the formula (I): or a pharmaceutically acceptable salt thereof, in which Ar1 and Ar2 are each X1 is -O-, -S-, -SO-, -SO2-, -NR34-, - N (COR12) - or -N (SO2R15) -； when X1 is -SO-, -SO2-, -N (COR12) - or -N (SO2R15) -, then: R1 and R2 are each independently selected from the group consisting of H, C1-C6 alkyl, hydroxy ( C1-C3 alkyl), C3-C8 cycloalkyl, -CH2F, -CHF2 and -CF3； or R1 and R2, together with the carbon atom to which both are attached, form a C3 to C6 alkylene ring； or when X1 is -O-, -S- or -NR34-, then: R1 and R2 are each independently selected from the group consisting of H, C1-C6 alkyl, hydroxy (C1-C3 alkyl), C3 cycloalkyl- C8, -CH2F, -CHF2 and -CF3； or R1 and R2, together with the carbon atom to which both are attached, form a C3 to C6 alkylene anyl； or R1 and R2, next to each other and the carbon atom to which they are attached, form a group C = O； R3 is selected from the group consisting of H C1-C6 alkyl, hydroxy- (C1-C3 alkyl), C3-C8 cycloalkyl, -CH2F, -CHF2 and -CF3； each R6 is independently selected from the group consisting of H, C1-C6 alkyl and -OH； each R7 is independently selected from the group consisting of H and C1-C6 alkyl； n2 is 1 to 4； R4 is selected from the group consisting of - (CR28R29) n1-G； in which n1 is 0 to 5； and G is H, -CF3, -CHF2-, -CH2F, -O- (C1-C6 alkyl), -OCH2F, -OCHF2, -OCF3, -OCH2CF3, -O- (C3-C8 cycloalkyl), -Oalkyl ( C1-C6) - (C3-C8 cycloalkyl), -NR13R14, -SO2NR13R14, -NR12SO2R13, -NR12C (O) R14, -NR12C (O) OR13, -NR12 (C (O) NR13R14), -C (O) NR13R14, -C (O) OR13, C3-C8 cycloalkyl, (R19) -aryl, (R18) -heteroaryl, -OC (O) R14, -OC (O) NR13R14, -C (= NOR14) (R13), -C (O) R13, -C (OR12) (R13) (R14), heterocycloalkenyl optionally substituted with 1 to 4 substituents independently selected from the group consisting of R30 and R31, R5 is selected from the group consisting of - ( CR28R29) n1-G, in which n1 is 0 to 5； and G is -CF3, -CHF2-, -CH2F, -O- (C1-C6 alkyl), -OCH2F, -OCHF2, -OCF3, -OCH2CF3, -5 O- (C3-C
