A Divergent and Selective Synthesis of Isomeric Benzoxazoles from a Single N-Cl Imine
Cheng-yi Chen*, Teresa Andreani and Hongmei Li
*Process Chemistry, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, United States, Email: cheng_chenmerck.com
C.-y Chen, T. Andreani, H. Li, Org. Lett., 2011, 13, 6300-6303.
DOI: 10.1021/ol202844c (free Supporting Information)
A divergent and regioselective synthesis of either 3-substituted benzisoxazoles or 2-substituted benzoxazoles from readily accessible ortho-hydroxyaryl N-H ketimines proceeds in two distinct pathways through a common N-Cl imine intermediate: (a) N-O bond formation to form benzisoxazole under anhydrous conditions and (b) NaOCl mediated Beckmann-type rearrangement to form benzoxazole, respectively.
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