Abstract: The invention relates to a compound of the following general formula [I] or a medicinally acceptable salt thereof, or a solvate thereof, ##STR1## wherein R.sup.1 represents alkyl, alkenyl, alkynyl, alkoxy, hydroxy, cyano, or halogen; R.sup.2 represents hydrogen, hydroxy, or halogen; R.sup.3 represents hydrogen, alkyl, or amidino; Ring A represents a 5 to 11-membered cyclic amino group which may be substituted, which cyclic amino group may be bridged between two carbon atoms in optional positions. The compound of this invention is useful for the prevention or treatment of cerebral tissue impairment due to the vasospasm following cerebral hemorrhage.