4-butoxy-2-butyl-2H-phthalazin-1-one

5-hydroxy-2,3-dihydrophthalazine-1,4-dione

3-hydroxy-2,3-dihydro-1H-pyrazolo[1,2-b]phthalazine-5,10-dione

6-chloro-3-methyl-[1,2,4]triazolo[3,4-a]phthalazine

phthalazino[2,3-b]phthalazine-5,7,12,14-tetrone