A (+)or (-) enantiomer of a compound of formula (I) wherein R.sup.4 is methyl or ethyl, or a salt, solvate or hydrate thereof, processes for preparing said compounds and pharmaceutical compositions containing them. Compounds of formula (+) are 5-HT.sub.1 -like agonists.
化合物公式(I)的A(+)或(-)对映体,其中R.sup.4是甲基或乙基,或其盐,溶剂合物或
水合物,制备该化合物的方法以及含有它们的药物组合物。公式(+)的化合物是5-HT.sub.1-类似激动剂。