Diazotization–azidation of amines in water by using crosslinked poly(4‐vinylpyridine)‐supported azide ion

Abstract

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 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. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 788-795, 2012

Diazotization–cyanation of aromatic amines with crosslinked poly(4‐vinylpyridine)‐supported cyanide ions

“…It is important to note that this polymeric reagent was stable and could be stored for a long time (months) without losing its activity; it could be readily used for the diazotization–cyanation of anilines. [P 4 ‐VP]I was recently prepared and used for the preparation of other functionalized polymers, including polymer‐supported thiocyanate, polymer‐supported carboxylate, polymer‐supported potassium ferrate, polymer‐supported azide ion,51 and polymer‐supported nitrite ion 46–50. Although [P 4 ‐VP]I is well known, [P 4 ‐VP]CN was used the first procedure for the direct diazotization–cyanation of aryl amines, and on the basis of our knowledge, there has been no report in the literature on the synthesis of aryl nitriles based on polymer‐supported cyanide ion.…”

“…Although polymer‐supported reagents, especially anion‐exchange resins, have been widely applied in organic synthesis,34–52 to the best of our knowledge, there has been no report on the synthesis of aryl nitriles via a dediazoniation–cyanation reaction based on polymer‐supported cyanide ions. Very recently Harrison and Hodge52 reported the synthesis of alkyl nitriles from alkyl halides with the Amberlyst A 26 CN − form.…”

“…Recently, we prepared crosslinked poly(4‐vinylpyridine)‐supported nitrite ions and examined their application in organic transformation, such as in the synthesis of nitro alkanes from alkyl halides,43 azo chromophores,46, 47 N ‐nitrosation of secondary amines,44, 45 nitration of aromatic compounds,48, 49 diazotization–iodination of aromatic amines (Sandmeyer type reaction),50 and diazotization–azidation of aromatic amines 51. In some of these studies, arenediazonium salts were generated in situ .…”

Solvent‐free diazotization–azidation of aryl amine using a polymer‐supported azide ion

“…The regioselective ring opening of polycyclic aromatic hydrocarbon epoxides by this polymer also reported by Lakshman et al60 Blass et al reported a one‐pot, two step preparation of functionalized 1,2,3‐triazoles by Merrifield resin supported ammonium azide anion 61. The 1,3‐dipolar cycloaddition by using poly (ethylene glycol)‐supported azide is also reported by Molteni et al62 Previously, we have also prepared crosslinked poly (4‐vinylpyridine)‐supported azide ion, [P 4 ‐VP]N 3 , and used for synthesis of alkyl azides from alkyl halides,56 diazotization‐azidation of amines in water57 and [2 + 3] cycloaddition reaction of azide ion with nitriles 58…”

“…Although polymer‐supported reagents especially anion exchange resins have been widely applied in organic synthesis,46–62 a literature search shows that there are a few reports in organic transformation based on polymer supported azide reagent. Brenelli et al reported that Amberlite IRA 900 supported azide resin is a highly effective reagent for the conversion of α‐haloketones into α‐azidoketones 59.…”