Synthesis of 2-(3-cyano-5-hydroxy-5-methyl-4-vinylene-1H-pyrrol-2(5H)-ylidene)malononitriles – novel functionalized analogs of tricyanofuran-containing (TCF) push–pull chromophores

Abstract2-(3-Cyano-5-hydroxy-4,5-dimethyl-1H-pyrrol-2(5H)-ylidene)malononitrile was synthesized by the interaction between malononitrile dimer and diacetyl. It reacts with aldehydes in ethanol in the presence of ammonium acetate at room temperature and results 2-(3-cyano-5-hydroxy-5-methyl-4-vinylene-1H-pyrrol-2(5H)-ylidene)malononitriles in 66–86% yield. The developed method is of interest as a promising approach to a novel group of push–pull chromophores, which are functionalized analogs of widely used chromophores of the tricyanofuran (TCF) series.GRAPHICAL ABSTRACT