There are described compounds of the formula ##STR1## where X is hydrogen, halogen, loweralkyl, loweralkoxy or trifluoromethyl; R is ##STR2## R.sub.4 being loweralkyl; R.sub.1 is hydrogen, loweralkyl or arylloweralkyl; R.sub.2 is hydrogen, loweralkyl or arylloweralkyl; and R.sub.3 is loweralkyl, with the proviso that when R is acetyl, R.sub.3 is methyl and X is hydrogen, R.sub.1 and R.sub.2 are not both hydrogen, or pharmaceutically acceptable acid addition salts thereof, which are useful for enhancing memory and for treating Alzheimer's disease.
描述了一种化合物的公式 ##STR1## 其中X为氢,卤素,低碳基,低碳氧基或三
氟甲基;R为 ##STR2## 其中R.sub.4为低碳基;R.sub.1为氢,低碳基或芳基低碳基;R.sub.2为氢,低碳基或芳基低碳基;R.sub.3为低碳基,但当R为乙酰基,R.sub.3为甲基且X为氢,R.sub.1和R.sub.2不同时为氢,或其药学上可接受的酸盐,用于增强记忆力和治疗阿尔茨海默病。