2963-65-7Relevant articles and documents
AN EFFICIENT PREPARATION OF 4-ARYLMETHYLISOXAZOL-5-ONES BY SELECTIVE REDUCTION OF THE 4-ARYLMETHYLENEISOXAZOL-5-ONES
Risitano, Francesco,Grassi, Giovanni,Foti, Francesco
, p. 5893 - 5896 (1983)
An efficient selective reduction of the exocyclic double bond of the 4-arylmethyleneisoxazol-5-ones with o-phenylenediamines and aldehydes is described. 4-arylmethylisoxazol-5-ones are produced in high yields together with comparable quantities of benzimidazoles.
One-Pot Transformation of Lignin and Lignin Model Compounds into Benzimidazoles
Guo, Tao,He, Jianghua,Liu, Tianwei,Zhang, Yuetao
, (2022/02/07)
It is a challenging task to simultaneously achieve selective depolymerization and valorization of lignin due to their complex structure and relatively stable bonds. We herein report an efficient depolymerization strategy that employs 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidant/catalyst to selectively convert different oxidized lignin models to a wide variety of 2-phenylbenzimidazole-based compounds in up to 94 % yields, by reacting with o-phenylenediamines with varied substituents. This method could take full advantage of both Cβ and/or Cγ atom in lignin structure to furnish the desirable products instead of forming byproducts, thus exhibiting high atom economy. Furthermore, this strategy can effectively transform both the oxidized hardwood (birch) and softwood (pine) lignin into the corresponding degradation products in up to 45 wt% and 30 wt%, respectively. Through a “one-pot” process, we have successfully realized the oxidation/depolymerization/valorization of natural birch lignin at the same time and produced the benzimidazole derivatives in up to 67 wt% total yields.
Cobalt ferrite magnetic nanoparticles as highly efficient catalyst for the mechanochemical synthesis of 2-aryl benzimidazoles
Borade, Ravikumar M.,Jadhav, K. M.,Kale, Swati B.,Pawar, Rajendra P.,Tekale, Sunil U.
, (2021/08/27)
A highly efficient magnetically separable nano cobalt ferrite catalyst was synthesized via the sol-gel auto combustion method, characterized by powder XRD, SEM, TEM, UV–Visible, FT-IR, magnetic study, and BET isotherm analysis. The synthesized material was found to be an efficient heterogeneous Lewis acid catalyst for the synthesis of 2-aryl benzimidazole derivatives via solvent-free mechanochemical synthesis. The notable features of this new protocol include solvent-free reaction, cost-effectiveness, good yields, and environmental friendliness to afford the products within a short reaction time along with easy recovery and reuse of the nano catalyst.