Ultrasonicwave-assisted tandem-reaction for synthesis of symmetrical vicinal diamines

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. (c) 2007 Wen Pei. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.