Six-membered ring benzo derivatives as DPP-4 inhibitor and use thereof

A compound having formula I, or a pharmaceutically acceptable salt or prodrug thereof, or an optically active isomer or solvate thereof:

• wherein:
• X is O
• A is a benzene ring with 1 to 5 substituents, wherein each substituent is independently a halogen, a cyano, a hydroxy, a C1-6 alkyl, a C1-6 alkyl substituted by halogen, a C1-6 alkoxy, or a C1-6 alkoxy substituted by halogen;
• A is a nitrogen-containing, or sulfur-containing five-membered or six-membered saturated or unsaturated heterocycle with 1 to 4 substituents, wherein each substituent is independently a halogen, a cyano, or a boronic acid group;
• or
• A is a heterocycle selected from the following structures:
• R is H, a halogen, a cyano, a hydroxy, a C1-6 alkyl, C1-6 alkyl with 1 to 5 F atoms, C1-6 alkoxy, or C1-6 alkoxy with 1 to 5 F atoms;
• n is an integer of 1-2;
• Ring B is an aromatic benzene ring, an aromatic heterocycle, a saturated or unsaturated 5-membered or 6-membered ring, a nitrogen-, oxygen-, or sulfur-containing five- or six-membered saturated or unsaturated heterocycle;
• R1 is independently selected from the group consisting of a halogen, a cyano, a hydroxy, a C1-6 alkyl, a C1-6 alkyl group containing 1 to 5 F atoms, a C1-6 alkoxy, a C1-10 alkylcarbonyloxy, a C1-3 alkoxymethoxy, a disubstituted OCH2CH2O and OCH2O, COOH, a C1-6 alkoxycarbonyl, a carbamoyl, a methylcarbamido, a cyanomethylcarbonyl, an acetamidomethylcarbonyl, a 2-pyrrocarbonyl, a methoxycarbonylmethyl, a 4-pyranylcarbonyl, a 4-morpholinecarbonyl, a 1-piperazinecarbonyl, an amino, a NR2R3, a C1-5alkylcarboxamido, a C3-5 alkyllactam group, a C1-6 alkylsulfonamido, a C3-5 alkylsultam group, a mercapto, a C1-6 alkylthio, a C1-6 alkylthio containing 1 to 5 F atoms, a C1-6 alkylsulfinyl, a C1-6 alkylsulfonyl, a C3-5 cycloalkylsulfonyl, and a C1-5alkylsulfinyl, a N-propanesulfonyllactam group, a N-butanesulfonyllactam group, and a 3-pyrazolylamino;
• m is an integer of 1 to 4;
• and
• R2, R3 are independently selected from a C1-6 alkyl, or R2 and R3 together form a substituted or unsubstituted 5- or 6-membered heterocycloalkyl, or a substituted or unsubstituted 5-or 6-membered heterocycle group additionally containing N or O.