Green Synthesis of Privileged Benzimidazole Scaffolds using Active Deep Eutectic Solvent

Abstract

The exploitation and use of alternative synthetic methods, in the face of classical procedures that do not conform to the ethics of Green Chemistry, represent an ever present problem in pharmaceutical industry. The procedures for the synthesis of benzimidazoles have become a focus in synthetic organic chemistry, as they are building blocks of strong interest for the development of compounds with pharmacological activity. Various benzimidazole derivatives exhibit important activities such as antimicrobial, antiviral, anti-inflammatory and analgesic and some of the already synthesized compounds have found very strong application in medicine praxis. Here we report a selective and sustainable method for the synthesis of 1,2-disubstituted or 2-substituted benzimidazoles, starting from o-phenylenediamine in the presence of different aldehydes. The use of deep eutectic solvent (DES) both as reaction medium and reagent without any external solvent provides advantages in terms of yields as well as in the work up procedure of the reaction.

Montmorillonite K10: An Efficient Organo- Heterogeneous Catalyst for Synthesis of Benzimidazole Derivatives

“…The reactions performed with 1 molar amount of aldehydes afforded the corresponding 2-monosubstituted benzimidazoles (1b-8b) in good yields without observing the formation of disubstituted derivative. This result is in accordance with the data reported in the literature [39,84]. 90% and 99%.…”

“…The products were isolated after evaporation of the solvent to afford compounds in 90-99 % yields. Spectral data were in accordance with the literature [39].…”

Enzymatic Synthesis of Glucose Monodecanoate in a Hydrophobic Deep Eutectic Solvent

“…Furthermore, DES are reported to be biodegradable and non-toxic [ 15 , 16 , 17 ] while exhibiting a high dissolution power for many different materials, including drugs, proteins, salts, sugars and surfactants [ 18 ]. DES are applicable as solvent or catalyst in a wide range of organic reactions, e.g., addition, cyclization, condensation and multicomponent reactions, and improve the activity or selectivity of these reactions compared to organic solvents [ 19 , 20 , 21 ]. However, DES present a suitable solvent not only for organic reactions but also for biocatalysis.…”

Sustainable and Selective Extraction of Lipids and Bioactive Compounds from Microalgae

“…15 mg of each oil was added to the internal standard (250 ng/ 100 μl chloroform, methyl tricosanoate, 23:0). The oil was subjected to transmethylation by treating 15 mg of the each oil with 6 mL of methanolic solution 0.2 M of sulfuric acid following standard procedure and 15 mg of hydroquinone [64]. The mixture was incubated for 12 hour at 60°C and subsequently cooled.…”