2-ethyl-1H-pyrrol-1-amine → Ethyl 5-[4-(3-cyanophenyl)-7-ethyl-2-methylpyrrolo[1,2-b]pyridazin-3-yl]pentanoate

Participants

Reaction Steps

To a solution of ethyl 6-(3-cyanobenzoyl)-7-oxooctanoate (3.18 g) in toluene (30 mL) was added 2-ethyl-1H-pyrrol-1-amine (1.17 g) and p-toluenesulfonic acid monohydrate (96 mg) at ambient temperature. The reaction mixture was refluxed for 1 hour. The mixture was evaporated in vacuo. The residue was purified by flash silica gel chromatography (silica gel, 200 mL) eluting with hexane-ethyl acetate=20-1, 15-1, and 10-1 to give ethyl 5-[4-(3-cyanophenyl)-7-ethyl-2-methylpyrrolo[1,2-b]pyridazin-3-yl]pentanoate (3.29 g, 83.8%) as an yellow oil.

Provenance & Evidence