The object of the present invention is to obtain new class of compounds which have improving effect on learning and memory disorders with good selectivity in central nervous system and little side effects and then to provide a good medicine for treatment of dementia. The present invention relates to the compounds represented by the following general formula or their pharmacologically acceptable salts and the drugs of improving learning or memory disorders comprising them as active ingredients. ##STR1## (wherein R.sup.1 and R.sup.2 are the same or different and are hydrogen, hydroxy, alkoxy, trifluoromethyl or halogen. A represents methyl, trifluoromethyl, or tert-butyl. Y represents O or NH.)
                            本发明的目的是获得一类新的化合物,其对学习和记忆障碍具有改善作用,在中枢神经系统中具有良好的选择性和少量的副作用,并提供一种治疗痴呆症的良好药物。本发明涉及以下一般式所表示的化合物或其药理学上可接受的盐,以及包含它们作为活性成分的改善学习或记忆障碍的药物。其中,R.sup.1和R.sup.2相同或不同,分别为氢、羟基、烷氧基、三
氟甲基或卤素。A代表甲基、三
氟甲基或叔丁基。Y代表O或NH。