Compound having inhibitory activity against O-glusacase and use thereof

A compound represented by Chemical Formula 1 below or a pharmaceutical salt thereof:

• wherein,
• D is a ring selected from the group consisting of substitutable C3 to C10 cycloalkyl, substitutable 5-membered unsaturated or aromatic ring, substitutable 6-membered unsaturated or aromatic ring, substitutable 5-membered unsaturated or aromatic heterocyclic ring, and substitutable 6-membered unsaturated or aromatic heterocyclic ring, or a polycyclic ring in which two or more rings selected from the group are fused,
• X1 is C, N, O or S,
• X2 is N or O,
• R1, R2 and R3 are each independently hydrogen or C1 to C5 alkyl,
• L is a direct bond or a C1 to C12 alkylene group, and
• n is an integer of 0 to 3.