Diazotization of anilines and diazo coupling with a coupling component mediated by a polymer‐supported sodium nitrite and a polymeric acid

Abstract

Polymer-supported reagents have become the subject of considerable and increasing interest as insoluble materials in the organic synthesis. In this study, diazonium salts are generated and are coupled with a coupling component by using a polymer supported nitrite and a polymeric acid. In this procedure, the azo chromo-phores are formed in a clean and efficient manner, the work-up is easy and yields are high to excellent.

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 .…”

Exploring Flow Procedures for Diazonium Formation

“…(E)-1-((4-Nitrophenyl)diazenyl)naphthalene-2-ol ( 32 ) [89]: Assessed loading 5.1 mmol, 78%; Isolated 1.30 g, 68%. 1 H-NMR (400 MHz, CDCl 3 ) δ/ppm: δ 16.12 (1H, s), 8.40 (1H, d, J = 8.1 Hz), 8.31 (2H, d, J = 9.1 Hz), 7.69 (1H, d, J = 9.6 Hz), 7.68 (2H, d, J = 9.4 Hz,), 7.59–7.50 (2H, m), 7.46–7.39 (1H, m), 6.69 (1H, d, J = 9.7 Hz).…”