A Practical Oxone®-Mediated, High-Throughput, Solution-Phase Synthesis of Benzimidazoles from 1,2-Phenylenediamines and Aldehydes and its Application to Preparative Scale Synthesis
Pierre L. Beaulieu*, Bruno Haché, Elisabeth von Moos
*Boehringer Ingelheim (Canada) Ltd., Research and Development, 2100 Cunard Street, Laval (Québec) H7S 2G5, Canada, Email: pbeaulieulav.boehringer-ingelheim.com
P. L. Beaulieu, B. Haché, E. von Moos, Synthesis, 2003, 1683-1692.
Addition of oxone to a mixture of a 1,2-phenylenediamine and an aldehyde in wet DMF results in rapid formation of benzimidazoles under very mild conditions. Products are isolated in high purity in most cases by simple aqueous precipitation. The reaction is applicable to a wide range of substrates but does not allow the conversion of aldehydes that are sensitive to oxone under acidic reaction conditions.
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