An efficient synthesis of the optically active isomers of 2H-1,4-benzoxazine derivatives, novel KATP channel modulators

2H-1,4-Benzoxazine amidine derivatives are drugs acting as modulators of the skeletal muscle and pancreatic beta cell ATP-sensitive-K+ (KATP) channels. With the aim of evaluating the influence of absolute configuration on the biological activity of these drugs, we herein report the optimization of a synthetic route to obtain both enantiomers of some of these compounds with improved chemical yield and high enantiomeric excess.