ethyl 3-bromo-4H-furo[3,2-b]pyrrole-5-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-furaldehyde was annulated according to Procedure H (aldehyde and azido-acetic acid ethyl ester added as ethanol solution (1 M of ester) to −20° C. ethoxide solution; −20° C. 35 min, −5° C. 1.5 h, 5° C. 15 min; reaction poured into cold saturated aqueous NH4Cl; after ether extraction, acrylate organic phase washed with water until aqueous phase was neutral; 0.5 M solution of crude acrylate heated).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-furaldehyde was annulated according to Procedure H (aldehyde and azido-acetic add ethyl ester added as ethanol solution (1 M of ester) to −20° C. ethoxide solution; −20° C. 35 min, −5° C. 1.5 h, 5° C. 15 min; reaction poured into cold saturated aqueous NH4Cl; after ether extraction, acrylate organic phase washed with water until aqueous phase was neutral; 0.5 M solution of crude acrylate heated).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-furaldehyde was annulated according to Procedure H (aldehyde and azido-acetic acid ethyl ester added as ethanol solution (1 M of ester) to −20° C. ethoxide solution; −20° C. 35 min, −5° C. 1.5 h, 5° C. 15 min; reaction poured into cold saturated aqueous NH4Cl; after ether extraction, acrylate organic phase washed with water until aqueous phase was neutral; 0.5 M solution of crude acrylate heated).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The title compound was synthesized from ethyl 3-bromo-4H-furo[3,2-b]pyrrole-5-carboxylate (200 mg, 0.774 mmol) using the conditions to synthesize ethyl 3-chloro-4H-thieno[3,2-b]pyrrole-5-carboxylate. Chromatography (silica gel, heptane/EtOAc) yielded ethyl 3-chloro-4H-furo[3,2-b]pyrrole-5-carboxylate (70 mg, 42% yield).