Ethyl orthoformate → 4-chloro-7-ethyl-7H-imidazo(4,5-c)pyridazine

Participants

Reaction Steps

A mixture of 5-chloro-N3-ethyl-pyridazine-3,4-diamine (Preparation 7, 10.0 g, 58 mmol) and triethylorthoformate (60 mL) were heated to reflux for 4 hours. The reaction mixture was concentrated in vacuo and the residue was dissolved in EtOAc (50 mL) and filtered. The filter cake was washed with EtOAc and then the organic layers were washed with saturated brine solution, dried over Na2SO4 and concentrated in vacuo to afford the title compound as a yellow solid in 45% yield, 4.8 g.

Provenance & Evidence