A compound of formula: in which: R' is selected from H and methyl; R 1 is C 1-3 alkyl substituted by CN or by one or more halogens; R 2 is selected from: wherein Y 6 is selected from N and CH; Z 1 is CR 3 R 4 or a bond; and Z 2 is CR 5 R 6, -C NR 8 -[Y 6] or -NR 8 C -[Y 6], where [Y 6] indicates which atom of Z 2 is attached to the ring containing Y 6; R 3 is selected from hydrogen, C 1-3 alkyl, halo, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylS 0-2 -C 1-2 alkyl, carboxyl and hydroxy-substituted-C 1-3 alkyl; R 4 is selected from hydrogen, amino, C 1-3 alkyl, cyano, hydroxy-ethyl and halo; or R 3 and R 4 together with the carbon atom to which R 3 and R 4 are attached form a 4 member saturated cyclic ring containing an oxygen molecule; R 5 is selected from hydrogen, halo, amino, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylcarbonyl, hydroxy and C 1-3 alkoxy; R 6 is selected from hydrogen, C 1-3 alkyl, halo, halo-substituted-C 1-3 alkyl; or R 4 and R 6 together with the carbon atom to which R 4 and R 6 are attached form 5-6 member unsaturated ring containing up to 2 heteroatoms selected from O, S and N; wherein said ring is optionally substituted with C 1-2 alkyl; R 8 is selected from hydrogen, C 1-3 alkyl-amino-carbonyl, C 1-3 alkyl- carbonyl, C 1-3 alkoxy and hydroxy-substituted-C 1-4 alkoxy, hydroxy-substituted-C 1-3 alkyl, and C 1-3 alkyl; R 9 is independently selected at each occurrence from hydrogen, fluorine, and methyl; Y 0 is selected from N, CH and CF; Y 1 is selected from N and CH; Y 2 is selected from N, CH, CF, CCl, C-NH 2, and C-C(R 9) 2 NH 2; Y 3 is selected from N and CH; Y 4 is selected from N and CH; or a pharmaceutically acceptable salt thereof. R' is selected from H and methyl; R 1 is C 1-3 alkyl substituted by CN or by one or more halogens; R 2 is selected from: wherein Y 6 is selected from N and CH; Z 1 is CR 3 R 4 or a bond; and wherein Y 6 is selected from N and CH; Z 1 is CR 3 R 4 or a bond; and Z 2 is CR 5 R 6, -C NR 8 -[Y 6] or -NR 8 C -[Y 6], where [Y 6] indicates which atom of Z 2 is attached to the ring containing Y 6; R 3 is selected from hydrogen, C 1-3 alkyl, halo, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylS 0-2 -C 1-2 alkyl, carboxyl and hydroxy-substituted-C 1-3 alkyl; R 4 is selected from hydrogen, amino, C 1-3 alkyl, cyano, hydroxy-ethyl and halo; or R 3 and R 4 together with the carbon atom to which R 3 and R 4 are attached form a 4 member saturated cyclic ring containing an oxygen molecule; R 5 is selected from hydrogen, halo, amino, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylcarbonyl, hydroxy and C 1-3 alkoxy; R 6 is selected from hydrogen, C 1-3 alkyl, halo, halo-substituted-C 1-3 alkyl; or R 4 and R 6 together with the carbon atom to which R 4 and R 6 are attached form 5-6 member unsaturated ring containing up to 2 heteroatoms selected from O, S and N; wherein said ring is optionally substituted with C 1-2 alkyl; R 8 is selected from hydrogen, C 1-3 alkyl-amino-carbonyl, C 1-3 alkyl- carbonyl, C 1-3 alkoxy and hydroxy-substituted-C 1-4 alkoxy, hydroxy-substituted-C 1-3 alkyl, and C 1-3 alkyl; R 9 is independently selected at each occurrence from hydrogen, fluorine, and methyl; Y 0 is selected from N, CH and CF; Y 1 is selected from N and CH; Y 2 is selected from N, CH, CF, CCl, C-NH 2, and C-C(R 9) 2 NH 2; Y 3 is selected from N and CH; Y 4 is selected from N and CH; R 3 is selected from hydrogen, C 1-3 alkyl, halo, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylS 0-2 -C 1-2 alkyl, carboxyl and hydroxy-substituted-C 1-3 alkyl; R 4 is selected from hydrogen, amino, C 1-3 alkyl, cyano, hydroxy-ethyl and halo; or R 3 and R 4 together with the carbon atom to which R 3 and R 4 are attached form a 4 member saturated cyclic ring containing an oxygen molecule; R 5 is selected from hydrogen, halo, amino, C 1-3 alkyl-amino-carbonyl, C 1-3 alkylcarbonyl, hydroxy and C 1-3 alkoxy; R 6 is selected from hydrogen, C 1-3 alkyl, halo, halo-substituted-C 1-3 alkyl; or R 4 and R 6 together with the carbon atom to which R 4 and R 6 are attached form 5-6 member unsaturated ring containing up to 2 heteroatoms selected from O, S and N; wherein said ring is optionally substituted with C 1-2 alkyl; R 8 is selected from hydrogen, C 1-3 alkyl-amino-carbonyl, C 1-3 alkyl- carbonyl, C 1-3 alkoxy and hydroxy-substituted-C 1-4 alkoxy, hydroxy-substituted-C 1-3 alkyl, and C 1-3 alkyl; R 9 is independently selected at each occurrence from hydrogen, fluorine, and methyl; Y 0 is selected from N, CH and CF; Y 1 is selected from N and CH; Y 2 is selected from N, CH, CF, CCl, C-NH 2, and C-C(R 9) 2 NH 2; Y 3 is selected from N and CH; Y 4 is selected from N and CH;