Phenyl phthalazine derivative, method for the preparation thereof, and pharmaceutical composition comprising the same

A compound represented by the following Chemical Formula 1, or a pharmaceutically acceptable salt thereof:

• in Chemical Formula 1,
• X is N,
• L1 is a single bond, C1-4 alkylene, C2-4 alkenylene, NH, O, or SO2,
• L3 is a single bond,
• R1 is hydrogen, C1-4 alkyl, C1-4 alkyl substituted with carboxy group, C1-4 haloalkyl, C1-4 alkoxy, C1-4 haloalkoxy, halogen, cyano, nitro, 4-methylpiperazin-1-carbonyl, carboxy, morpholino, (C1-4 alkyl)sulfonyl, (piperidinyl)sulfonyl, or (piperazinyl)sulfonyl,
• R3 is hydrogen, or C1-4 alkyl,
• R4 is hydrogen, or halogen,
• n is 1 or 2, and
• A-L2-R2 is represented by the following formula 1′:
• in Chemical Formula 1′,
• Y is N, is a single bond,
• Z is CH, or N,
• n1 is 1,
• n2 is 1 or 2,
• L2 is NH, and
• R2 is C1-4 alkyl unsubstituted or substituted with amino;
• C3-6 cycloalkyl;
• amino;
• N(C1-4 alkyl)2;
• hydroxy;
• morpholino;
• or pyrrolidinyl.