Propionic anhydride → 1-(4-Cyanophenyl)-2-ethylimidazo[4,5-c]pyridine

Participants

Reaction Steps

A mixture of 3-amino-4-(4'-cyanophenyl)aminopyridine (Preparation 26(b)) (2.00 g, 9.5 mmol) and propionic anhydride (12.2 ml, 95 mmol) were heated together under nitrogen at reflux for 17 hours. The resulting solution was treated with excess aqueous sodium bicarbonate and the product was extracted into dichloromethane (3×150 ml). The combined extracts were dried (MgSO4), concentrated under reduced pressure, and the residue was purified by flash chromatography (gradient elution with ethyl acetate/methanol) to give the title compound as a brown solid (510 mg, 22%).

Provenance & Evidence