Facile Construction Of An Amino-1,3-Oxazine Scaffold Using Burgess Reagent Under Mild Conditions

The development of a cyclization reaction to access amino-1,3-oxazines under mild conditions is described. The synthesis was achieved using dehydrating reagents, such as phosphorus pentoxide and Burgess reagent. In particular, the cyclization with Burgess reagent proceeded under mild conditions and tolerated potentially labile functional groups, such as the acetoxy group, and therefore can be used to synthesize beta-secretase (BACE1) inhibitors with a variety of amino-1,3-oxazine warheads. (C) 2020 Elsevier Ltd. All rights reserved.