Rapid synthesis of 2-amino maleonitrile Schiff bases in aqueous media catalyzed by cerium(IV) ammonium nitrate (CAN) and a new method for the one-pot preparation of their dicyano imidazoles (DCI)

摘要

A quick and simple method has been developed for the synthesis of 2-amino maleonitrile Schiff bases 3(a-k) through the reaction of 2,3-diaminomaleonitrile (DAMN) and aromatic aldehydes in the presence of catalytic amounts of cerium(IV) ammonium nitrate (CAN) in aqueous media at room temperature. Also, the facile synthesis of 2-aryl-4,5-dicarbonitrile imidazoles 4(a-k) by one-pot condensation of DAMN with various aromatic aldehydes using CAN as efficient reagent in acetonitrile at 50 A degrees C has been described. In this way, the one-pot synthesis of raw materials is presented for the first time. The new synthesized compounds were characterized using IR, H-1 NMR, C-13 NMR and mass spectroscopy. The present procedure offers several advantages, such as good to excellent yields, the use of an inexpensive and available catalyst, easy and quick isolation of the pure product and short reaction times compared with previous reports.