Acetic Acid → Diethyl 1H-pyrrole-2,4-dicarboxylate

Participants

Reaction Steps

To a stirred solution of ethyl isocyanoacetate (0.02 mol, 2.3 mL) and DBU (3.0 g, 0.02 mol) in THF (30 mL) was added a solution of formaldehyde (0.6M THF solution, 16.6 mL, 0.01 mole) at 45-50° C. for a period of 15 min. After stirring for 5 hr at the same temperature, the reaction mixture was neutralized with HOAc and the solvents were removed under reduced pressure. The resulting oil was partitioned between satd. aq. NaHCO3 and EtOAc. The EtOAc layer was separated, dried with Na2SO4 and concentrated in vacuo to obtain a viscous oil which was chromatographed on silica (20% EtOAc—hexanes) to give 403A (0.80 g, 38%). MS Found: (M+H)+=212.0;

Provenance & Evidence