Efficient protocol for the synthesis of quinoxaline, benzoxazole and benzimidazole derivatives using glycerol as green solvent

Recent Advances in the Use of Glycerol as Green Solvent for Synthetic Organic Chemistry

“…In addition, protocols for the synthesis of quinaxoline and benzoxazole derivatives by condensation of oaminophenol and o-phenylenediamine with aldehydes or 1,2-diketones, respectively, in glycerol have also been developed by Telvekar and co-workers [50]. 8 Scheme 7.…”

Diphosphorus Tetraiodide (P2I4): An Efficient Catalyst for Synthesis of 2-Aryl-1,3-benzazoles via Cyclocondensation of o-Amino/Mercaptan/Hydroxy Anilines with Aryl Acids

“…There are several classical methods in the literature to obtain 1,3-benzazoles which involves the condensation reactions of either o-phenylenediamine, o-aminobenzenethiol, or o-aminophenol with substituted carboxylic acids, aldehydes, acyl chlorides, or nitriles [9][10][11][12][13][14][15]. Alternatively, benzimidazoles have also been synthesized using transition-metal catalyzed amination followed by condensation [16] and cyclization of o-nitroaniline derivatives with aryl isothiocyanates [17].…”

Easy, Simplistic and Green Synthesis of Various Benzimidazole and Benzoxazole Derivatives Using PEG₄₀₀ as a Green Solvent

“…Similarly, benzoxazole is the core ring structure in the non-steroidal antiinflammatory drug flunoxaprofen, as well as a natural product [11,12]. Various methods have been reported for the synthesis of benzimidazole and benzoxazole derivatives by using a variety of starting material and catalyst at different temperature [15][16][17][18]. However, these methods suffer from many problems such as long reaction time, usage of expensive and corrosive reagent, catalyst and harmful to the environment due to the use of organic solvents and high temperature with lesser yield.…”