56463-47-9Relevant articles and documents
Nitroarenes as versatile building blocks for the synthesis of unsymmetrical urea derivatives and N-Arylmethyl-2-substituted benzimidazoles
Rodríguez-Huerto, Paula A.,Pe?a-Solórzano, Diana,Ochoa-Puentes, Cristian
, p. 6275 - 6283 (2021/07/29)
In this contribution, a fast and simple method for the synthesis of unsymmetrical urea derivatives and N-arylmethyl-2-substituted benzimidazoles was developed starting from nitroarenes. The reaction of nitroarenes and phenyl isocyanate or phenyl isothiocyanate in tin (II) chloride dihydrate/choline chloride eutectic mixture afforded the expected urea and thiourea derivatives, while the reaction of different aldehydes with o-nitroaniline or 4-methoxy-2-nitroaniline shows a markedly high preference for the obtention of N-arylmethyl-2-substituted benzimidazoles over the 2-substituted analogues. This method offers a straightforward alternative to obtain the target compounds in good to excellent yields with short reaction times employing an operationally simple experimental set-up. Graphic abstract: [Figure not available: see fulltext.] A series of unsymmetrical urea and thiourea derivatives together with 1,2-disubstituted benzimidazoles are easily obtained in good yields starting from nitroarenes employing the eutectic mixture tin (II) chloride dihydrate/choline chloride as reductive reaction media.
Metal-free selective synthesis of 2-substituted benzimidazoles catalyzed by Br?nsted acidic ionic liquid: Convenient access to one-pot synthesis of N-alkylated 1,2-disubstituted benzimidazoles
Senapak, Warapong,Saeeng, Rungnapha,Jaratjaroonphong, Jaray,Promarak, Vinich,Sirion, Uthaiwan
, p. 3543 - 3552 (2019/05/29)
A novel efficient method for the selective synthesis of 2-substituted benzimidazoles is described through condensation reaction of o-phenylenediamines with a wide rang of aliphatic, aromatic and heteroaromatic aldehyde substrates using Br?nsted acidic ionic liquid as a reusable catalyst under metal-free conditions at ambient temperature. Notably, Dodecylimidazolium hydrogen sulfate ([DodecIm][HSO4]) is the most efficient catalyst for good to excellent yields of the corresponding products (up to 98%). Subsequently, this protocol was successfully applied for the preparation of N-alkylated 1,2-disubstituted benzimidazoles in high to excellent yields via sequential one-pot reaction. In addition, catalysts are recycled at least four times without significant loss in activity.
One-pot strategy of copper-catalyzed synthesis of 1,2-disubstituted benzimidazoles
Xie, Caixia,Han, Xushuang,Gong, Jian,Li, Danyang,Ma, Chen
, p. 5811 - 5819 (2017/07/22)
A simple, one-pot and copper-catalyzed coupling reaction for the construction of 1,2-disubstituted benzimidazole derivatives is described. A low-cost copper salt and a weak base K3PO4 were utilized in this reaction. A variety of 1,2-disubstituted benzimidazoles were obtained in moderate to excellent yields.