Beta secretase inhibitors

摘要

An excellent beta secretase inhibitor is provided, which comprises a compound of the general formula: wherein Ar is an aromatic group; X is a divalent group selected from -O-, -S-, -CO-, -SO-, -SO₂-, -NR⁸-, CONR⁸-, -SO₂NR⁸-, and -COO- (wherein R⁸ is hydrogen, etc.), a divalent C_1-6 aliphatic hydrocarbon group which may contain one or two of these divalent groups, or a bond; Y is a divalent group selected from -O-, -S-, -CO-, -SO-, -SO₂-, -NR⁸-, -CONR⁸-, -SO₂NR⁸-, and -COO-, or a divalent C_1-6 aliphatic hydrocarbon group which may contain one or two of these divalent groups; R¹ and R² are hydrogen, a hydrocarbon group, etc., respectively; and A is a ring which may be further substituted, or a salt thereof.