Abstract: The invention concerns compounds having the formula I ##STR1## wherein Ar is a phenyl or benzyl group which is optionally substituted with hydroxy or alkoxy;R.sup.1 is hydrogen, lower alkyl, lower alkoxy, hydroxy;R.sup.2 is hydrogen, lower alkyl;R.sup.3 is NR.sup.4 R.sup.5, whereinR.sup.4 and R.sup.5 which can be the same or different, are lower alkyl, or wherein R.sup.4 and R.sup.5, when taken together, form a ring with the nitrogen atom, whereby said ring optionally is substituted with lower alkyl;n is 0 or 1;m is 2 or 3 andtheir salts with physiologically acceptable acids and when the compounds can be in form of optical isomers, the racemic mixture and the individual isomers, for the treatment of disorders of the urinary bladder.