Benzimidazole condensed ring systems. 2 [1]. New synthesis of substituted 1-oxo-1H,5-H-pyrido[1,2-a]benzimidazole-4-carbonitriles and related derivatives

Article abstract of DOI:10.1002/jhet.5570250622

The synthesis of some 3-substituted and 2,3-disubstituted-1-oxo-1H,5-H-pyrido[1,2-a]benzimidazole-4-carbonitr les 5,6 by fusing 1H-benzimidazole-2-acetonitrile 1 with some β-keto esters 2,4 in the presence of ammonium acetate or with ethyl β-aminocrotonat