A compound of formula: wherein R 1 is hydrogen, cyano, formyl, C 1 -C 6 alkylcarbonyl, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 haloalkylcarbonyl, C 1 -C 6 alkoxyC 1 -C 6 alkylcarbonyl, C 3 -C 6 cycloalkylcarbonyl, C 1 -C 6 alkoxyC 1 -C 3 alkoxycarbonyl, C 1 -C 6 alkoxyoxalyl, C 1 -C 6 alkoxycarbonylC 1 -C 4 alkylC 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkylsulfanylcarbonyl, or phenylcarbonyl; R 2 and R 3 are each independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, halogen, or C 1 -C 6 alkoxyC 1 -C 2 alkyl; R 4 is C 1 -C 8 alkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxy, C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkylC 1 -C 2 alkyl, wherein said cycloalkyl groups are optionally substituted with 1 to 3 groups represented by R 6, phenyl, phenylC 1 -C 3 alkyl, heteroaryl, heteroarylC 1 -C 3 alkyl, wherein said heteroaryl is a 5- or 6-membered aromatic monocyclic ring comprising 1, 2, 3 or 4 heteroatoms individually selected from nitrogen, oxygen and sulfur, heterocyclyl, heterocyclylC 1 -C 3 alkyl, wherein said heterocyclyl is a 4-, 5- or 6-membered non-aromatic monocyclic ring comprising 1, 2 or 3 heteroatoms or groups individually selected from nitrogen, oxygen, sulfur, and S 2, wherein said heterocyclyl groups are optionally substituted with 1 or 2 groups represented by R 7, or a 5- to 10-membered non-aromatic spirocyclic carbobi- or carbotri-cyclyl ring system optionally comprising 1, 2, 3, 4 or 5 heteroatoms individually selected from nitrogen, oxygen and sulfur, and optionally bonded to the rest of the molecule through a C 1 -C 2 alkylene linker; R 5 is phenyl or heteroaryl, wherein said heteroaryl is a 5- or 6-membered aromatic monocyclic ring comprising 1, 2 or 3 heteroatoms individually selected from nitrogen, oxygen and sulfur, and wherein said phenyl or said heteroaryl group are optionally substituted by 1, 2 or 3 substituents, which may be the same or different, selected from R 6; R 6 is halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, or C 1 -C 4 haloalkyl; R 7 is halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, or C 1 -C 4 haloalkoxy; or a salt or an N-oxide thereof. R 1 is hydrogen, cyano, formyl, C 1 -C 6 alkylcarbonyl, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 haloalkylcarbonyl, C 1 -C 6 alkoxyC 1 -C 6 alkylcarbonyl, C 3 -C 6 cycloalkylcarbonyl, C 1 -C 6 alkoxyC 1 -C 3 alkoxycarbonyl, C 1 -C 6 alkoxyoxalyl, C 1 -C 6 alkoxycarbonylC 1 -C 4 alkylC 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkylsulfanylcarbonyl, or phenylcarbonyl; R 2 and R 3 are each independently hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, halogen, or C 1 -C 6 alkoxyC 1 -C 2 alkyl; R 4 is C 1 -C 8 alkyl, C 1 -C 8 haloalkyl, C 1 -C 8 alkoxy, C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkylC 1 -C 2 alkyl, wherein said cycloalkyl groups are optionally substituted with 1 to 3 groups represented by R 6, phenyl, phenylC 1 -C 3 alkyl, heteroaryl, heteroarylC 1 -C 3 alkyl, wherein said heteroaryl is a 5- or 6-membered aromatic monocyclic ring comprising 1, 2, 3 or 4 heteroatoms individually selected from nitrogen, oxygen and sulfur, heterocyclyl, heterocyclylC 1 -C 3 alkyl, wherein said heterocyclyl is a 4-, 5- or 6-membered non-aromatic monocyclic ring comprising 1, 2 or 3 heteroatoms or groups individually selected from nitrogen, oxygen, sulfur, and S 2, wherein said heterocyclyl groups are optionally substituted with 1 or 2 groups represented by R 7, or a 5- to 10-membered non-aromatic spirocyclic carbobi- or carbotri-cyclyl ring system optionally comprising 1, 2, 3, 4 or 5 heteroatoms individually selected from nitrogen, oxygen and sulfur, and optionally bonded to the rest of the molecule through a C 1 -C 2 alkylene linker; R 5 is phenyl or heteroaryl, wherein said heteroaryl is a 5- or 6-membered aromatic monocyclic ring comprising 1, 2 or 3 heteroatoms individually selected from nitrogen, oxygen and sulfur, and wherein said phenyl or said heteroaryl group are optionally substituted by 1, 2 or 3 substituents, which may be the same or different, selected from R 6; R 6 is halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, or C 1 -C 4 haloalkyl; R 7 is halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, or C 1 -C 4 haloalkoxy; or a salt or an N-oxide thereof.