Synthesis of imidazo[1,2-c]quinazolin-5(6H)-ones promoted by low-valent titanium(TiCl_4/Sm system)

A series of imidazo[1,2-c]quinazolin-5(6H)-one derivatives were synthesized by the reductive cyclization of 2-(2-nitrophenyl)imidazoles with triphosgene promoted by low-valent titanium.The structures of all products obtained were characterized by IR and 1HNMR spectra.This method has the advantages of mild reaction condition and high yield.