Imidazothiazole derivative that has a proline ring structure

compound represented by the general formula (1) or a salt thereof: wherein Ar1 represents a phenyl group which may have one or more substituents selected from a halogen atom, a cyano group and a C1-C6 alkyl group; Ar2 represents a phenyl group that may have one or more substituents selected from a halogen atom, a C1-C6 alkyl group and a cyano group, or a pyridyl group that may have one or more substituents selected from a halogen atom, a group C1-C6 alkyl and a cyano group; R1 represents a C1-C6 alkyl group which may have one or more substituents selected from a halogen atom, a hydroxy group, a C1-C6 alkoxy group, a carbamoyl group, an amino group, a C1-C6 alkanoyl group and a group cyano, a C1-C6 alkanoyl group which may have one or more substituents selected from a halogen atom, a hydroxy group, a C1-C6 alkoxy group, a carbamoyl group, an amino group and a cyano group, a hydrogen atom, or a hydroxy group; R2 and R3 each independently represent a C1-C6 alkyl group which may have one or more substituents selected from a halogen atom, a hydroxy group, a C1-C6 alkoxy group, a carbamoyl group, an amino group, a C1 alkanoyl group -C6 and a cyano group, or a hydrogen atom, or R2 and R3 can together form an oxo group, or R2 and R3 together with the carbon atoms to which R2 and R3 are respectively attached can form a saturated hydrocarbon ring 3 to 5 members in a spiro or condensed form; R4 represents a C1-C6 alkyl group which may have one or more substituents selected from a halogen atom, a hydroxy group, a C1-C6 alkoxy group, a carbamoyl group, an amino group, a C1-C6 alkanoyl group and a group cyano; R5 represents a C1-C6 alkyl group which may have one or more substituents selected from a halogen atom, a hydroxy group, a C1-C6 alkoxy group, a carbamoyl group, an amino group, a C1-C6 alkanoyl group and a group cyano; R6 represents a hydrogen atom; and R7 represents a halogen atom.