A novel one-pot benzimidazole ring formation via a continuous flow selective reductive cyclization method

Balázs Szabó, F. Faigl, János Éles, István Greiner

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1 Citation (Scopus)

Abstract

A novel, simple and efficient laboratory scale continuous flow protocol has been elaborated for one-pot benzimidazole synthesis via a reductive cyclization method using the commercially available H-Cube Pro. Coupling with a stainless steel microreactor (4mL reactor volume), the acylation of o-nitroaniline was successfully joined in the hydrogenation step without any isolation or purification steps. This concept enabled a fully integrated process using a standard 5% Pt/C, sulfide catalyst for the reductive cyclization of 2-nitroacetanilide with quantitative yield. Compared with the previously reported batch processes, the present procedure facilitated efficient synthesis of a broad range of benzimidazole derivatives bearing functionalities sensitive to reductive cleavage and acidic conditions (10 compounds, 82 to >99% selectivity).

Original languageEnglish
Pages (from-to)1940-1944
Number of pages5
JournalCurrent Organic Chemistry
Volume22
Issue number19
DOIs
Publication statusPublished - Jan 1 2018

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Keywords

  • Benzimidazole
  • Continuous flow
  • Heterocycles
  • One-pot
  • Reductive cyclization
  • Selective synthesis

ASJC Scopus subject areas

  • Organic Chemistry

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