Ammonia → Ethyl 2-methyl-3-pyrrolecarboxylate

Participants

Reaction Steps

Vinyl acetate (13.4 g) was added dropwise over 2 hr to bromine (25 g) under ice-cooling with stirring. The reaction mixture was further stirred at the same temperature for 1 hr. Ethyl 3-oxobutanoate (18.5 g) was added, and 25% aqueous ammonia solution (44 mL) was added dropwise over 1 hr. The reaction mixture was further stirred at room temperature for 30 min, water was added and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→3:1) and recrystallized from hexane to give the title compound as a colorless solid (yield 7.56 g, 35%).

Provenance & Evidence