Compounds of formula I ##STR1## wherein X.sup.a, X.sup.b, R, R.sup.1 and R.sup.2 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.
式I的化合物:##STR1## 其中X.sup.a、X.sup.b、R、R.sup.1和R.sup.2具有规范中给定的任何含义,它们的药学上可接受的盐可用于治疗尿失禁的
钾通道开放剂。还公开了制药组合物、制备式I化合物和中间体的过程。