Synthesis 2010(3): 398-402  
DOI: 10.1055/s-0029-1217136
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© Georg Thieme Verlag Stuttgart ˙ New York

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
Fax: +91(40)27160387; e-Mail: dsb@iict.res.in; e-Mail: bose_iict@yahoo.co.in;
Further Information

Publication History

Received 21 September 2009
Publication Date:
20 November 2009 (online)

Abstract

Dess-Martin periodinane (DMP), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the intramolecular cyclization of phenolic azomethines/Schiff bases at ambient temperature leading to the rapid and expeditious synthesis of substituted benzoxazoles and benzothiazoles. Furthermore, a solution-phase strategy has been developed by treating the reaction mixtures sequentially with Amberlyst A-26 thiosulfate resin and diisopropylaminomethyl resin (PS-DIEA), which remove excess reagent and byproducts, to give pure products.