A compound represented by the following general formula: [wherein R represents hydrogen, a chain or cyclic hydrocarbon group optionally having a substituent, or a heterocyclic group optionally having a substituent; and (i) Ar 1 represents a 2-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 2-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-methoxy-4-[2-(piperidin-1-yl)ethoxy]phenyl group, a 2-methoxy-4-[2-(4-methylpiperazino)ethoxy]phenyl group, a 2-methoxy-4-(2-morpholinoethoxy)phenyl group, a 4-(β-D-glucopyranosyl)oxy-2-methoxyphenyl group, a 4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-[2-(4-benzylpiperazino)ethoxy]-4-methoxyphenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-dimethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-pyrrolidinoethoxy)phenyl group, or a 4-diethylamino-2-[2-(piperidin-1-yl)ethoxy]phenyl group, and Ar 2 represents an indol-2-yl group, an indol-3-yl group, an indol-4-yl group, an indol-5-yl group, an indol-6-yl group, an indol-7-yl group, a benzotriazol-5-yl group, a benzimidazol-5-yl group, a quinoxalin-6-yl group, a benzofuran-2-yl group, a benzothiophen-2-yl group, a 1H-indazol-5-yl group, a 7-azaindol-3-yl group, a quinolin-2-yl group, a quinolin-5-yl group, a quinolin-8-yl group, a 1,4-benzodioxan-6-yl group, a 1,3-benzodioxol-5-yl group, a chromon-3-yl group, a coumarin-6-yl group, a 7-methoxycoumarin-4-yl group, or a 4-methoxycoumarin-6-yl group;] or a salt thereof. [wherein R represents hydrogen, a chain or cyclic hydrocarbon group optionally having a substituent, or a heterocyclic group optionally having a substituent; and (i) Ar 1 represents a 2-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 2-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-methoxy-4-[2-(piperidin-1-yl)ethoxy]phenyl group, a 2-methoxy-4-[2-(4-methylpiperazino)ethoxy]phenyl group, a 2-methoxy-4-(2-morpholinoethoxy)phenyl group, a 4-(β-D-glucopyranosyl)oxy-2-methoxyphenyl group, a 4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-[2-(4-benzylpiperazino)ethoxy]-4-methoxyphenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-dimethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-pyrrolidinoethoxy)phenyl group, or a 4-diethylamino-2-[2-(piperidin-1-yl)ethoxy]phenyl group, (i) Ar 1 represents a 2-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 2-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-methoxy-4-[2-(piperidin-1-yl)ethoxy]phenyl group, a 2-methoxy-4-[2-(4-methylpiperazino)ethoxy]phenyl group, a 2-methoxy-4-(2-morpholinoethoxy)phenyl group, a 4-(β-D-glucopyranosyl)oxy-2-methoxyphenyl group, a 4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-3-ylmethoxy)phenyl group, a 3-methoxy-4-(tetrahydrofuran-2-ylmethoxy)phenyl group, a 2-[2-(4-benzylpiperazino)ethoxy]-4-methoxyphenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-dimethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-morpholinoethoxy)phenyl group, a 4-diethylamino-2-(2-pyrrolidinoethoxy)phenyl group, or a 4-diethylamino-2-[2-(piperidin-1-yl)ethoxy]phenyl group, and Ar 2 represents an indol-2-yl group, an indol-3-yl group, an indol-4-yl group, an indol-5-yl group, an indol-6-yl group, an indol-7-yl group, a benzotriazol-5-yl group, a benzimidazol-5-yl group, a quinoxalin-6-yl group, a benzofuran-2-yl group, a benzothiophen-2-yl group, a 1H-indazol-5-yl group, a 7-azaindol-3-yl group, a quinolin-2-yl group, a quinolin-5-yl group, a quinolin-8-yl group, a 1,4-benzodioxan-6-yl group, a 1,3-benzodioxol-5-yl group, a chromon-3-yl group, a coumarin-6-yl group, a 7-methoxycoumarin-4-yl group, or a 4-methoxycoumarin-6-yl group;] or a salt thereof.