Functionalized Bipyrroles and Pyrrolyl-Aminopyrones from Acylethynylpyrroles and Diethyl Aminomalonate

An efficient method for the synthesis of 1H,1’H-2,3’-bipyrroles (in up to 72% yield) by the cyclocondensation of easily available 2-(acylethynyl)pyrroles with diethyl aminomalonate hydrochloride has been developed. The reaction proceeds under reflux in MeCN (6 h) in the presence of Cs2CO3. Under the same conditions, 2-(acylethynyl)pyrroles with bulky (benzyl and octyl) substituents at nitrogen atom react with diethyl aminomalonate to afford 1H,2’H-2,3’-bipyrroles and pyrrolyl-aminopyrones.