Synthesis of 3-aminoimidazo[1,2-a]pyridines via three-component reaction in the 2,2,2-trifluoroethanol-water two-phase systems

An efficient synthesis of 3-aminoimidazo[1,2-a]pyridines via three-component reaction from aromatic aldehydes, 2-aminopyridines and isonitriles at room temperature in water/2,2,2-trifluoroethanol two-phase systems is described. In this methodology equivalent or better yield was obtained in the two-phase systems when compared to pure 2,2,2-trifluoroethanol for reaction. The use of the two-phase system also reduces the consumption of CF3CH2OH by 75% leading to a significant reduction in cost as well as toxicity of the reaction media. The strong hydrogen bond donation properties can also eliminate the need for Lewis acid catalyst, further simplifying the procedure. High yield, short reaction time, simple work up without need to column chromatography and use of mild and environmental friendliness conditions are some of benefits of the present method in synthesis of this biologically compounds.