Substituted heterocyclic compound containing alpha-ketone framework, and use thereof

A compound as shown in formula I or a pharmaceutically acceptable salt thereof:

• wherein,
• Ar is an unsubstituted, monosubstituted, or polysubstituted heteroaromatic ring;
• wherein the heteroaromatic ring is selected from:
• furan, thiophene, pyrrole, oxazole, isoxazole, imidazole, pyrazole, thiazole, isothiazole, triazole, 1,3,4-oxadiazole, 1,3,4-thiadiazole, 1,2,4-oxadiazole, 1,2,4-thiadiazole, pyridine, pyrimidine, pyridazine, benzoxazole, benzothiazole, purine, quinoline, isoquinoline, indazole, oxazolo[4,5-b]pyridine, and oxazolo[5,4-b]pyridine;
• R1 represents H or aryl or heteroaryl;
• L represents a linker, selected from —O—, —S—, —NR4—,
• n=0, 1, 2, 3;
• R4 is selected from H, C1-C8 straight or branched halogenated alkyl, halogenated cycloalkyl, C1-C8 straight or branched alkyl, cycloalkyl;
• is selected from
• R2 is selected from H, methyl, ethyl, acetyl, phenyl, pyridyl, methoxycarbonyl, propionyl, methoxyacetyl, and ethoxyacetyl;
• R3 is selected fromH, F, Cl, Br, I, CF3, CN, hydroxyl, methoxy, methyl, nitro, thiol, carboxyl, vinyl, bromomethyl, cyanomethyl, aryl, heterocyclyl, C1-C10 straight or branched alkyl, cycloalkyl, C1-C10 straight or branched alkyl substituted thiol group, C1-C10 straight or branched alkyl ester group.