Dess-Martin Periodinane Mediated Intramolecular Cyclization of Phenolic Azomethines: A Solution-Phase Strategy toward Benzoxazoles and Benzothiazoles
D. Subhas Bose*, Mohd. Idrees
*Organic Chemistry Division III, Fine Chemicals Laboratory, Indian Institute of Chemical Technology, Hyderabad, Tarnaka 500 007, India, Email: dsbiict.res.in
D. S. Bose, M. Idrees, Synthesis, 2010, 398-402.
Dess-Martin periodinane (DMP) efficiently mediates the intramolecular cyclization of phenolic azomethines at ambient temperature leading to substituted benzoxazoles and benzothiazoles. Treatment of the reaction mixtures sequentially with Amberlyst A-26 thiosulfate resin and diisopropylaminomethyl resin (PS-DIEA) removes excess reagent and byproducts, to give pure products.
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D. S. Bose, M. Idrees, J. Org. Chem., 2006, 71, 8261-8263.