The present invention provides compounds of Formula (I) and a method of treating Alzheimer's disease using a compound of Formula (I), wherein: R¹ and R² include alkyl and phenylalkyl; R³ is hydrogen or alkyl; and R₄ and R₅ include alkyl, alkoxy, carboxyl, alkoxycarbonyl, and nitro. Also provided is a method of inhibiting the aggregation of amyloid proteins using a compound of Formula (I) ##STR1##

and a method of imaging amyloid deposits using compounds of Formula (I).