One-step synthesis of pyrido[1,2-a]benzimidazole derivatives by a novel multicomponent reaction of chloroacetonitrile, malononitrile, aromatic aldehyde, and pyridine.
Polysubstituted pyrido[1,2-a]benzimidazole derivatives are efficiently produced in moderate yields in a novel one-pot, four-component reaction from pyridine or 3-picoline, chloroacetonitrile, malononitrile, and aromatic aldehyde in refluxing acetonitrile. The mechanism of this novel reaction was believed involving the formation of polysubstituted benzenes with subsequent substitution and annulation reaction of pyridine. All pyrido[1,2-a]benzimidazoles, polysubstituted benzenes, polysubstituted indoles, and some key reaction intermediates are characterized by (1)H and (13)C NMR, MS, IR spectra, and elemental analysis as well as X-ray crystallography.
Yan
Chao Guo
CG
College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China. cgyan@yzu.edu.cn
Wang
Qi Fang
QF
Song
Xiao Kai
XK
Sun
Jing
J