Synthesis of 2‐substituted benzimidazoles by iodine‐mediated condensation of orthoesters with 1,2‐phenylenediamines

Abstract

Iodine was found to be an efficient catalyst for the synthesis of 2‐substituted benzimidazoles by the condensation of orthoesters and 1,2‐phenylenediamines in good to excellent yields under mild reaction conditions.

Synthetic Approaches to 2-Arylbenzimidazoles: A Review

“…Synthesis of 2-substituted benzimidazoles were also reported by the reaction of o-phenylenediamines or amines with orthoesters using various catalyst such as hexafluoroisopropanol [199], Lewis acids [200], sulfamic acid [201], iodine [202] (Scheme 19). 2-Arylbenzimidazoles have been synthesizing using various methods.…”

Convenient Two-step One-pot Synthesis of Benzimidazoles Using 2-nitroanilines and Thiourea Dioxide

“…All products were characterised by 1 H NMR, 13 C NMR, IR and HR-MS. Data of compounds 2a-h were in accordance with previous reports. [17][18][19][20] In conclusion, a new two-step one-pot synthesis of a series of substituted benzimidazoles had been reported. Compared with earlier methods, this procedure has several advantages including catalyst-free reaction, simplicity in experiments and work-up, and use of water as solvent.…”

A Convenient Synthesis of Bisbenzimidazoles from Iminoester Hydrochlorides Via Microwave Technique

“…There are several methods known for the synthesis of bisbenzimidazole derivatives. The most common protocol involves a cyclocondensation reaction of 3,3′‐diaminobenzidine ( 1 ) with various groups such as ketones , ortoesters , and 1,3‐dicarbonyl compounds (Scheme ). However, these protocols suffer from one or more disadvantages such as prolonged reaction time, use of special reagents, and vigorous reaction conditions.…”