4-[[3-[4-(cyclopropanecarbonyl)piperazine-1-carbonyl]-4-fluorophenyl]methyl]-2H-phthalazin-1-one 4-[[3-[4-(cyclopropanecarbonyl)piperazine-1-carbonyl]-4-fluoro-phenyl]methyl]-2H-phthalazin-1-one 4-[[3-[[4-(cyclopropyl-oxomethyl)-1-piperazinyl]-oxomethyl]-4-fluorophenyl]methyl]-2H-phthalazin-1-one 4-[3-[4-(cyclopropanecarbonyl)piperazine-1-carbonyl]-4-fluoro-benzyl]-2H-phthalazin-1-one 4-[[3-(4-cyclopropylcarbonylpiperazin-1-yl)carbonyl-4-fluoro-phenyl]methyl]-2H-phthalazin-1-one