4-Aminopyridine → 3-Ethoxy-4-(pyridin-4-ylamino)cyclobut-3-ene-1,2-dione

Participants

Reaction Steps

To a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (5.00 g, 29.4 mmol) in absolute ethanol (100 mL) was added a suspension of 4-aminopyridine (2.77 g, 29.4 mmol) in ethanol (50 mL). The reaction mixture was refluxed for 4 hours then concentrated to give crude product. Chromatography (EtOAc) afforded 0.632 g (10%) of a white solid: mp 120°-125° C.

Provenance & Evidence