Beta-amyloid protein production/secretion inhibitors

摘要

A compound of the formula: wherein Ar is an aromatic group; X and Y are a bivalent group selected from -O-, -S-, -CO-, -SO-, -SO2-, -NR<8>-,-CONR<8>-, SO2NR<8> and -COO- (wherein R<8> is H, a hydrocarbon group or acyl), or a bivalent C1-6 aliphatic hydrocarbon group which may contain one or two above bivalent groups; R<1> and R<2> are H or C1-6 alkyl, or R<1> and R<2> may form, together with the adjacent nitrogen atom, a nitrogen-containing heterocyclic ring; and ring A is a monocyclic aromatic ring, or a salt thereof or a prodrug thereof exhibits an excellent inhibitory activity of the production and/or the secretion of amyloid- beta protein.