Acetic Anhydride → HCID 15171503, compound

Participants

Reaction Steps

2,3-Diaminopyridine (28 g, 0.256 mole) and acetic anhydride (30 mL, 0.38 mole) were stirred at room temp in methylene chloride (770 mL) for 30 min. The mixture was concentrated in vacuo to a brown solid. Recrystallization from methylene chloride/hexane (10/1) gave off-white crystals (21.9 g, 57%) of 3-acetamido-2-aminopyridine. This acetamide was combined with 3-chloro-2,4-pentanedione (20 g, 0.146 mole) in abs. ethanol (350 mL) and stirred under reflux for 20 hrs. After cooling, the mixture was diluted with methylene chloride (300 mL) and washed with water (3×300 mL). The organic phase was dried over magnesium sulfate and concentrated to a green solid. Recrystallization from methylene chloride/hexane (1/1) gave the title compound as green crystals (7.3 g, 21%. m.p. 173°-175° C.).

Provenance & Evidence