The use of polymeric reagents simplifies routine azidation of diazonium salts, because it eliminates the traditional purification. An efficient, simple, and effective method for the preparation of aryl azides is described. The synthesis of aromatic azides from the corresponding amines is accomplished under mild conditions with sodium nitrite in the presence of p-toluenesulfonic acid or concentrated H(2)SO(4) at low temperature (0-5 degrees C to room temperature). The obtained relatively stable diazonium salts, followed by treatment with a polymer-supported azide ion in water at room temperature to produce the corresponding aryl azides. The spent polymeric reagents can be regenerated and reused for several times without losing their activity. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123:788-795, 2012