Click Reaction of Epoxides with Anthranilic Acids Using Neat Grinding To Access Benzoxazepines
Atul K. Singh, Ruchi Chawla, Lal Dhar S. Yadav*
*Green Synthesis Lab, Department of Chemistry, University of Allahabad, Allahabad 211 002, India, Email: ldsyadavhotmail.com
A. K. Singh, R. Chawla, L. D. S. Yadav, Synthesis, 2012, 44, 2353-2358.
An atom-economic, efficient, rapid, and highly regioselective one-pot click reaction allows the synthesis of benzo[e][1,4]oxazepin-5-ones in excellent yields. The method involves epoxide ring-opening-ring-closing cascade with anthranilic acids using neat grinding at room temperature in the presence of lithium bromide as a mild catalyst. Pure products are obtained simply by washing the reaction mixture with warm water.
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