摘要 |
A compound of formula (I): <IMAGE> (I) wherein Y1, Y2, Y3 and Y4 are each hydrogen, halogen, nitro, cyano, hydroxyl, thiol, amino, alkyl, haloalkyl, alkylthio, a protected or unprotected carboxyl, a protected or unprotected sulfonamide, or tetrazol; one of R1 and R2 is hydrogen, alkyl, aryl, aralkyl, oxazolyl, or a protected or unprotected carboxyl and the other of R1 and R2 is hydrogen, alkyl, aryl or aralkyl; and R3 is hydrogen or an amino protecting group, and pharmaceutically acceptable salts or esters thereof. The compounds are effective for treating dementia, Alzheimer's disease and delirium and are effective as sedatives. |