Pyrazolopyridazines

1-tert-butyl-4-methyl-1,6-dihydro-7H-pyrazolo[3,4-d]pyridazin-7-one

4-cyclopropyl-1-(4-fluorophenyl)-1,6-dihydro-7H-pyrazolo[3,4-d]pyridazin-7-one

4-isopropyl-1-phenyl-1H-pyrazolo[3,4-d]pyridazine-7-thiol

4-methyl-1-phenyl-1H-pyrazolo[3,4-d]pyridazine-7-thiol

7-chloro-4-methyl-1-phenyl-1H-pyrazolo[3,4-d]pyridazine

4-methyl-1-phenyl-1,6-dihydro-7H-pyrazolo[3,4-d]pyridazin-7-one