The present invention relates to a compound formula (I) wherein X.sub.1 is
bond or --O--CH.sub.2 --, (II) or (III) R.sup.1 is hydrogen or an amino
protective group, a is phenyl, indolyl or carbazolyl, each of which may be
substituted with one or two substituent(s), and B is hydrogen; halogen;
lower alkyl; lower alkoxycarbonyl; cyclo(lower)alkyl; or a heterocyclic
group, naphthyl, 1,2,3,4-tetrahydronaphthyl, benzyl or phenyl, each of
which may be substituted with one or two substituent(s), or a salt
thereof. The compound (I) of the present invention and pharmaceutically
acceptable salts thereof are useful for the prophylactic and/or the
therapeutic treatment of pollakiures or urinary incontinence.
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