methyl 5-[(E)-2-(4-chlorophenyl)vinyl]4-nitrothiophene-2-carboxylate → methyl 5-(4-chlorophenyl)-4H-thieno[3,2-b]pyrrole-2-carboxylate

Participants

Reaction Steps

A solution (1 M) of methyl 5-[(E)-2-(4-chlorophenyl)vinyl]4-nitrothiophene-2-carboxylate in triethyl phosphite was heated to reflux for 20 h. After cooling down a part of the solvent was evaporated under high vacuum (2 mbar, water bath 60° C.) then the residue was purified by flash chromatography on silica gel (1:20 acetone/toluene). Fractions containing the title compound along with some phosphorous impurities were concentrated to give a residue that was triturated with AcOEt/petroleum ether (1:9) and filtered to afford the title compound (16%) as a solid.

Provenance & Evidence