Direct synthesis of 2-aryl-1,3-benzoselenazoles by reaction of bis(2-aminophenyl) diselenides with aryl aldehydes using sodium metabisulfite

We present here a general and easy method for the synthesis of several 2-aryl-1,3-benzoselenazoles from the reaction of bis(2-aminophenyl) diselenides with different aryl aldehydes, promoted by the non-toxic inorganic reducing agent sodium metabisulfite (Na2S2O5) in DMSO at 120 °C. This efficient method furnishes in high yields the corresponding 2-aryl substituted 1,3-benzoselenazoles and tolerates a range of substituents at the aryl ring of aldehydes. The use of focused microwave irradiation decreases drastically the reaction time from 48 to 2 h.