4-ethyl-7-(methylsulfonyl)-1-phenyl-1H-imidazo<4,5-d>pyridazine

2-(3-Phenyl-3H-imidazo[4,5-d]pyridazin-4-yl)-malonic acid diethyl ester

1,2-diphenyl-7-(methylsulfonyl)-1H-imidazo<4,5-d>pyridazine

3-Oxo-2-(3-phenyl-3H-imidazo[4,5-d]pyridazin-4-yl)-butyric acid ethyl ester

Cyano-(3-phenyl-3H-imidazo[4,5-d]pyridazin-4-yl)-acetic acid ethyl ester