Synlett 2020; 31(06): 547-552
DOI: 10.1055/s-0039-1690797
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© Georg Thieme Verlag Stuttgart · New York

A Green, Scalable, One-Minute Synthesis of Benzimidazoles

Vijayaragavan Elumalai
UiT The Arctic University of Norway, Department of Chemistry, Chemical Synthesis and Analysis Division, Hansine Hansens veg 54, 9037 Tromsø, Norway   Email: jorn.h.hansen@uit.no   Email: vijayaragavan.elumalai@uit.no
,
Jørn H. Hansen∗
› Author AffiliationsThe authors gratefully acknowledge funding for this work by the Research Council of Norway (Grant no. 275043 CasCat).
Further Information

Publication History

Received: 08 October 2019

Accepted after revision: 20 December 2019

Publication Date:
24 January 2020 (online)

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Published as part of the ISySyCat2019 Special Issue

Abstract

Herein is reported a substantially improved synthesis of 2-substituted benzimidazoles by condensation of 1,2-diaminoarenes and aldehydes using methanol as the reaction medium. The developed method afforded moderate to excellent yields (33–96%) at ambient temperature, displays high functional group tolerance, is conducted open to air, and requires only one minute reaction time under catalyst- and additive-free conditions. Moreover, the efficient protocol permits scale-up to multi-gram scale synthesis of benzimidazoles and will become a method of choice when constructing such heterocyclic systems.

Key words

benzimidazoles - green synthesis - rapid condensation - heterocyclization - 1,2-diaminoarenes - catalyst-free reactions

Supporting Information

    Supporting information for this article is available online at https://doi.org/10.1055/s-0039-1690797. Included are detailed procedures, characterization data, and NMR spectra.
  • Supporting Information
 

  • References and Notes

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