A compound of Formula (I), or pharmaceutically acceptable salts and/or hydrates or prodrugs thereof, wherein Formula (I) has the structure: ##STR00001## is provided, wherein R.sub.1-R.sub.7 are defined herein. These compounds are useful in medicaments for treating a disease selected from the group consisting of Alzheimer's Disease, amyloid angiopathy, cerebral amyloid angiopathy, systemic amyloidosis, hereditary cerebral hemorrhage with amyloidosis of the Dutch type, inclusion body myositis, mild cognitive impairment (MCI) and Down's syndrome, in a subject.