7-[4-[4-(8-fluoronaphthalen-1-yl)piperazin-1-yl]butoxy]-3,4-dihydro-1H-1,8-naphthyridin-2-one 7-[4-[4-(8-fluoro-1-naphthyl)piperazin-1-yl]butoxy]-3,4-dihydro-1H-1,8-naphthyridin-2-one 7-[4-[4-(8-fluoro-1-naphthyl)-1-piperazinyl]butoxy]-3,4-dihydro-1H-1,8-naphthyridin-2-one