The synthesis of a series of 9-amino-1, 2, 3, 4-tetrahydroacridin-l-ols is reported. These compounds are related to 1, 2, 3, 4-tetrahydro-9-acridinamine (THA, tacrine). They inhibit acetylcholinesterase in vitro and are active in a model that may be predictive of activity in Alzheimer's disease-the scopolamine-induced impairment of 24-h memory of a passive dark- avoidance paradigm in mice. Two compounds,(i)-9-amino-1, 2, 3, 4-tetrahydroacridin-l-01 ...