The present invention provides a compound selected from2-((3,4-Dimethoxyphenyl)-1-methyl-4-(2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-yl)piperazine or a salt thereof；1-[4-(Methylsulfonyl)phenyl]-4-(2,4,6,7-tetramethyl-2,3-dihydro-1-benzofuran-5-yl)pi perazine or a salt thereof；4-[4-(2,4,6,7-Tetramethyl-2,3-dihydro-1-benzofuran-5-yl)piperazin-1-yl]benzamide or a salt thereof；1-((3,4-Dimethoxyphenyl)-4-(2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-yl)pip erazine or a salt thereof；1-((4-Methoxyphenyl)-4-(7-methoxy-2,4,6-trimethyl-2,3-dihydro-1-benzofuran-5-yl)pi perazine or a salt thereof；1-{4-[4-(2,2,4,6,7-Pentamethyl-2,3-dihydro-1-benzofuran-5-yl)piperazin-1-yl]phenyl}ethanone or a salt thereof；{5-[4-(4-Methoxyphenyl)piperazin-1-yl]-2,4,6,7-tetramethyl-2,3-dihydro-1-benzofuran-2-yl}methanol or a salt thereof；1-((2,4-Dimethoxyphenyl)-4-(2,4,6,7-tetramethyl-2,3-dihydro-1-benzofuran-5-yl)pipera zine or a salt thereof； and1-((2,2,4,6,7-pentamethyl-2,3-dihydro-1-benzofuran-5-yl)-4-(1H-pyrazole-3-yl)piperazine or a salt thereof.
