A practical synthesis of symmetrical vicinal diamines with broad chemistry scope is described. The key step is the ultrasonicwave promoted tandem-reaction, two-step reaction sequence combining Mannich double condensations with benzotriazole, glyoxal and primary or secondary amines and reduction of the bis(benzotriazole)-adducts with sodium borohydride proceeded smoothly in tetrahydrofuran in high yield at room temperature.