An efficient method for nitration of aromatic compounds over solid acid and polymer‐supported sodium nitrite

Abstract

A variety of aromatic compounds are nitrated under heterogeneous conditions using a polymersupported hydrochloric acid, [P 4 -(VP)]HCl, with a polymersupported sodium nitrite, [P 4 -VP]NO 2 , or sodium nitrite in ethanol at room temperature with high yields. This methodology is useful for nitration of activated aromatic com-pounds. In this procedure, the work-up is very easy, and the spent polymeric reagent can be regenerated and reused.

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 .…”

Convenient synthesis of sulfonamides from amines and p‐toluene sulfonyl chloride mediated by crosslinked poly(4‐vinylpyridine)

“…Although the applications of polymeric reagent in organic synthesis have been rapidly developed,31–54 but, there are a few reports on sulfonamide synthesis by polymeric reagents in literature 15, 54. Barrett et al reported54 only one example for synthesis of N ‐benzyl phenylsulfonamide by using polyvinylpyridine.…”

“…In continuing of our studies on application of crosslinked poly(4‐vinylpyridine)37–53 in organic synthesis, herein we wish to report a green, clean, and simple method for synthesis of sulfonamides from amines and TsCl by using crosslinked poly(4‐vinylpyridine) as a polymeric catalyst, base or substrate, under heterogeneous conditions.…”