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Direct Synthesis of N-Monosubstituted Benzimidazol-2-ones via Ph3P-I2-Mediated Reaction of Hydroxamic Acids

Nittaya Wiriya, Dolnapa Yamano, Surat Hongsibsong, Mookda Pattarawarapan, Wong Phakhodee*

*Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand, Email:

N. Wiriya, D. Yamano, S. Hongsibsong, M. Pattarawarapan, W. Phakhodee, Synlett, 2022, 33, 1468-1472.

DOI: 10.1055/s-0040-1719897

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The combination of Ph3P and I2 promotes a synthesis of benzimidazolones from readily accessible hydroxamic acids. Upon Lossen-type rearrangement of the O-activated hydroxamic acids, the in situ generated isocyanates undergo an intramolecular attack by ortho N-nucleophiles producing the cyclized products in good yields under mild conditions.

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Key Words

benzimidazol-2-ones, hydroxamic acids, triphenylphosphine, iodine, Lossen rearrangement

ID: J72-Y2022