A novel synthesis of 1-aryl tetrazoles promoted by employing the synergy of the combined use of DMSO and an ionic liquid as the solvent system at ambient temperature

The synergy of the combined use of DMSO and an ionic liquid viz. (bbim)*Br- has brought about a mild, convenient, efficient, and rapid protocol for the synthesis of 1-substituted-1H-1,2,3,4-tetrazoles via the condensation of amines, triethyl orthoformate, and sodium azide at ambient temperature in excellent isolated yields (85-90%). The inherent Bronsted acidity of ionic liquid and high polarity of both IL and DMSO resulted in a significant enhancement in the reaction rate. (C) 2009 Elsevier Ltd. All rights reserved.