Efficient Access to o‐Phenylendiamines and Their Use in the Synthesis of a 1,2‐Dialkyl‐5‐trifluoromethylbenzimidazoles Library Under Microwave Conditions

Abstract

A quick access toward a 1,2‐dialkyl‐5‐trifluoromethylbenzimidazoles library by a three‐step synthesis sequence starting from 1‐chloro‐2‐nitro‐4‐(trifluoromethyl)benzene is described. The synthesis proceed via o‐phenylendiamines eficiently isolated, which also are key synthetic intermediates of another valuable heterocyclic compounds. Likewise, the trifluoromethyl group is part of the obtained benzimidazoles, affording an important structural feature for their possible applications. The advantages of this methodology are the modular lipophilicity of products, easy work‐up, up to 83% overall yield, the convenient use of microwave‐assisted reactions, and the production of compounds (intermediates and products) of high‐added value using cheap reagents and simple protocols.

Studies via X-ray analysis on intermolecular interactions and energy frameworks based on the effects of substituents of three 4-aryl-2-methyl-1H-imidazoles of different electronic nature and their in vitro antifungal evaluation

“…Imidazoles are an important class of very stable aromatic N-heterocycles frequently found in natural products, metalloenzymes, pharmaceuticals and other functional synthetics (Fox, 1943;Sezen & Sames, 2003;Ritterskamp et al, 2017;Vargas-Oviedo et al, 2017). Today, the wide variety of studies on imidazole synthesis have become a 'master key' of research due to the wide range of applications of imidazole derivatives in diverse biological and industrial processes (Vichier-Guerre et al, 2016;Arepally et al, 2017;Rajendiran et al, 2018).…”

Influence of Steric Effect on the Pseudo-Multicomponent Synthesis of N-Aroylmethyl-4-Arylimidazoles

“…Thus, the methods for imidazole synthesis are extensive and can be classified in three general ways: (i) cyclocondensation reactions (the most usual), (ii) a scaffold approach, and (iii) multicomponent reactions (MCRs) [2,7,[16][17][18][19][20][21][22]. Several methods have been perfected using microwave-assisted organic synthesis (MAOS) as a powerful tool for various chemical transformations with superior results compared to conventional methods [20,[23][24][25][26].…”

Orthoesters in heterocycle synthesis

“…A fourth paper reported a synthesis of bis(1,3,4-oxadiazol-2-yl)phenylmethyl sulfides 32 from 1,1'diphenylthiodiacetic acid dihydrazide (31) and several triethyl orthoesters. 14 This reaction led not only to the desired sulfide-linked heterocycles, but also resulted in cleavage of the carbon-sulfur bond in the substrate with formation of oxadiazoles 33 and 34.…”