New nitroindazolylacetonitriles: efficient synthetic access via vicarious nucleophilic substitution and tautomeric switching mediated by anions

Abstract

New N-alkyl-nitroindazolylacetonitriles were efficiently obtained via vicarious nucleophilic substitution of N-methyl-nitroindazoles with 4-chlorophenoxyacetonitrile. All compounds were fully characterized by NMR and mass spectroscopy techniques and the structures of some of them were additionally confirmed by X-ray diffraction analysis data. Tautomeric switching was observed in this series of nitroindazolylacetonitriles upon addition of basic anions followed by UV-Vis spectrophotometric and ¹H-NMR titrations. The formation of tautomeric species induced by anionic species was endorsed by Density Functional Theory calculations.