one-step synthesis of dicyano imidazoles by (nh4)2ce(no3)6/hno3 promoted oxidative cyclocondensation of an aldehyde and 2,3-diaminomaleonitrile

The purpose of this study is to obtain a facile, mild, and effective synthetic method for the one-pot synthesis of 2-aryl-4,5-dicarbonitrile imidazole derivatives 3a-q from oxidative cyclo-condensation of aromatic aldehydes and 2,3-diaminomaleonitrile (damn) by cerium(iv) ammonium nitrate/nitric acid (can/na) as a novel and efficient oxidation catalyst. this synthetic protocol is cost-effective in addition to other advantages such as rapid transformation with good to excellent yields of products, one-step process and avoiding the pre-functionalization of the starting materials, simple workup procedure and easy operation under mild conditions in comparison previously report. these valuable conditions may be ideally suited for an effective synthesis of dicyano imidazole heterocycles on a larger scale.