A reinvestigation of the acid-promoted heterocyclization of 2-(2-oxo-2-arylethyl)malononitriles in the presence of amines

作者：Martins Carla; Eleuterio Ana; Carreiras M Carmo^*; Samadi Abdelouahid; Soriano Elena; Leon Rafael; Marco Contelles Jose

来源：Molecular Diversity, 2009, 13(4): 459-468.

DOI：10.1007/s11030-009-9130-3

• 2-(2-Oxo-2-arylethyl)malononitriles
• 2-Amino-5-arylfuran-3-carbonitriles
• 2-Amino-5-aryl-1-phenyl-1H-pyrrole-3-carbonitriles
• 2-Amino-5-arylfuran-3(4)-(di)carbonitriles
• MWI
• Reaction mechanism
• DFT

The reinvestigation of the acid-promoted cyclization of 2-(2-oxo-2-arylethyl)malononitriles, in the presence of benzylamine or aniline, in ethanol or acetonitrile, has confirmed that this is a long-time reaction process for a low-yielding synthesis of 2-amino-5-arylfuran-3-carbonitriles (2), or 2-amino-5-aryl-1-phenyl-1H-pyrrole-3-carbonitriles (4), depending on the base used. However, the microwave-assisted synthesis of 2-amino-5-(4'-methoxyphenyl)furan-3(4)-(di)carbonitriles (2c and 3c) proceeds in shorter reaction times and higher yields than does the classical thermal heating protocol. In these reactions we have observed for the first time, and characterized by their spectroscopic data and X-ray analysis, the unexpected formation of 2-amino-5-aryl-3 (4)-(di)carbonitriles (3), whose formation has been rationalized by density functional theory (DFT) analysis of the proposed reaction mechanism.

• 出版日期2009-11
• 单位河北医科大学