A compound represented by Chemical Formula I, its racemate, or a pharmaceutically acceptable salt thereof: wherein ring A is an aryl group or a heteroaryl group selected from the group consisting of Chemical Formulae to (VIII): in which X is O, S, or N-Y, Y is selected from the group consisting of H, a linear or branched alkyl group of C1 to C5, and a cyclic alkyl group of C3 to C5, R1, which is linked to any one of aromatic carbons of ring A, is selected from the group consisting of H; a linear or branched alkyl group of C1 to C5; a cyclic alkyl group of C3 to C5; O-R3; -N R5; and a phenyl, a pyridine, a furan, a thiazol, a thiophene, a hydro-1H-isoquinoline, and an isoxazole groups, with one to three hydrogen atoms being substituted with R2, R2 is selected from the group consisting of H, a halogen atom, a linear or branched alkyl group of C1 to C5, a cyclic alkyl group of C3 to C5, a trifluoromethyl group, a nitro group, - O-R6, and -N R8, R3 is selected from the group consisting of H, a linear or branched alkyl group of C1 to C4, a cyclic alkyl group of C3 to C5, -CH 2 -cyclic alkyl of C5 to C6, -CH 2 -aryl of C6 to C10, and -CH 2 -heteroaryl of C2 to C8 with at least one of O, N, and S on the aromatic ring, R4 and R5, which are the same with or different from each other, are each independently selected from the group consisting of H and a linear or branched alkyl group of C1 to C5, or R4 and R5 is linked to form a 5-7 membered ring, wherein the 5-7 membered ring is a non-substituted one or has a phenyl group as a substituent; R6 is selected from the group consisting of H and a linear or branched alkyl group of C1 to C3; and R7 and R8, which are the same with or different from each other, are each independently selected from the group consisting of H and a linear or branched alkyl group of C1 to C3, or R7 and R8 is linked to form a 5-7 membered ring. wherein ring A is an aryl group or a heteroaryl group selected from the group consisting of Chemical Formulae to (VIII): in which X is O, S, or N-Y, Y is selected from the group consisting of H, a linear or branched alkyl group of C1 to C5, and a cyclic alkyl group of C3 to C5, R1, which is linked to any one of aromatic carbons of ring A, is selected from the group consisting of H; a linear or branched alkyl group of C1 to C5; a cyclic alkyl group of C3 to C5; O-R3; -N R5; and a phenyl, a pyridine, a furan, a thiazol, a thiophene, a hydro-1H-isoquinoline, and an isoxazole groups, with one to three hydrogen atoms being substituted with R2, R2 is selected from the group consisting of H, a halogen atom, a linear or branched alkyl group of C1 to C5, a cyclic alkyl group of C3 to C5, a trifluoromethyl group, a nitro group, - O-R6, and -N R8, R3 is selected from the group consisting of H, a linear or branched alkyl group of C1 to C4, a cyclic alkyl group of C3 to C5, -CH 2 -cyclic alkyl of C5 to C6, -CH 2 -aryl of C6 to C10, and -CH 2 -heteroaryl of C2 to C8 with at least one of O, N, and S on the aromatic ring, R4 and R5, which are the same with or different from each other, are each independently selected from the group consisting of H and a linear or branched alkyl group of C1 to C5, or R4 and R5 is linked to form a 5-7 membered ring, wherein the 5-7 membered ring is a non-substituted one or has a phenyl group as a substituent; R6 is selected from the group consisting of H and a linear or branched alkyl group of C1 to C3; and R7 and R8, which are the same with or different from each other, are each independently selected from the group consisting of H and a linear or branched alkyl group of C1 to C3, or R7 and R8 is linked to form a 5-7 membered ring.