1,4-benzoxazine derivatives as potassium channel openers

摘要

Compounds of formula I (I) wherein Xa, Xb, R, R1 and R2 have any of the meanings given in the specification, and their pharmaceutically acceptable salts are useful as potassium channel openers for the treatment of urinary incontinence. Also disclosed are pharmaceutical compositions, processes for preparing the compounds of formula I and intermediates.