| 摘要 |
PROBLEM TO BE SOLVED: To provide a medicine having high affinity to anα7-nicotine receptor and useful for treating Alzheimer's disease or a cognitive function failure. SOLUTION: A spiro ring compound expressed by general formula (wherein, R<1> is H, methyl, ethyl, acetyl, chlorine, bromine or hydroxymethyl; R<2> is H, methyl, ethyl, acetyl, cyano, bromine or hydroxymethyl; and R<3> and R<4> are each absent or oxygen). An optically active isomer, a pharmaceutically used salt or a hydrate of the compound is provide. |
