Synthesis of 1, 2-disubstituted benzimidazoles by reaction of N-substituted benzene-1,2-diamine with different aldehydes was developed. This greener procedure proceeds with the help of oxygen in water at 60oC. The advantages of proposed method are catalyst-free conditions in water, short reaction time and excellent yields. | Catalyst-free synthesis of 1 2-disubstituted benzimidazoles in aqueous media using oxygen as the oxidant Current Chemistry Letters 9 2020 63 70 Contents lists available at GrowingScience Current Chemistry Letters homepage Catalyst-free synthesis of 1 2-disubstituted benzimidazoles in aqueous media using oxygen as the oxidant Manoj P. Thakare Rahimullah Shaikh and Dipak Tayade Department of Chemistry Government Vidarbha Institute of Science and Humanities Amravati 444604 India CHRONICLE ABSTRACT Article history Synthesis of 1 2-disubstituted benzimidazoles by reaction of N-substituted benzene-1 2- Received January 2 2017 diamine with different aldehydes was developed. This greener procedure proceeds with the Received in revised form help of oxygen in water at 60oC. The advantages of proposed method are catalyst-free March 1 2017 conditions in water short reaction time and excellent yields. Accepted April 21 2017 Available online July 27 2019 Keywords Catalyst-free Benzimidazole Aqueous media Oxygen 2020 Growing Science Ltd. All rights reserved. 1. Introduction Benzimidazoles are the very important unit in the heterocycles due to their biological as well as pharmaceutical importance. The interest of researchers towards benzimidazole containing heterocycles was increased because 5 6-dimethyl-1- α-D-ribofuranosyl benzimidazole is a basic part of vitamin The scaffold like benzimidazole is observed in a number of compounds of pharmaceutical Benzimidazoles exhibit a lot of biological activities like anti -cancer 3 anti-fungal 4 anti- bacterial 5 anti-leishimanial 6 antiviral 7 8 anti-inflammatory and antiulcer agents9 activities. Benzimidazoles are also used as organic ligands 10 fluorescent whitening agent dyes 11 and functional Classical methods of benzimidazoles synthesis include the condensation of 1 2 - phenylenediamines with either aldehydes13-16 or carboxylic acids under relatively harsh 18 .
