Tricyclic compound, and preparation method therefor and medical use thereof

A compound of formula (I):

• or a mesomer, racemate, enantiomer, diastereomer thereof, or mixture thereof, or a prodrug thereof, or a pharmaceutically acceptable salt thereof,
• wherein:
• A1 is selected from the group consisting of N and CR1;
• A2 is selected from the group consisting of N and CR2;
• ring A is selected from the group consisting of
• refers to the site attached to the phenyl moiety;
• R1 and R2 are each independently selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, hydroxy, thiol, oxo, alkyl, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, —C(O)Ra, —O(O)CRa, —C(O)ORa, —C(O)NRaRb, —NHC(O)Ra, —S(O)mRa, —S(O)mNRaRb and —NHS(O)mRa;
• R3 is selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, hydroxy, thiol, oxo, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, —C(O)Ra, —O(O)CRa, —C(O)ORa, —C(O)NRaRb, —NHC(O)Ra, —S(O)mRa, —S(O)mNRaRb and —NHS(O)mRa;
• X and Y are each independently selected from the group consisting of O and NR4;
• R4 is selected from the group consisting of hydrogen, halogen, amino, nitro, cyano, hydroxy, thiol, oxo, alkyl, alkoxy, haloalkyl, haloalkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, —C(O)Ra, —O(O)CRa, —C(O)ORa, —C(O)NRaRb, —NHC(O)Ra, —S(O)mRa, —S(O)mNRaRb and —NHS(O)mRa;
• R5 and R6 are each independently selected from the group consisting of hydrogen, halogen, amino, cyano, hydroxy, thiol, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl, wherein the alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl are each optionally further substituted by one or more substituents selected from the group consisting of halogen, amino, nitro, cyano, hydroxy, thiol, carboxy, ester group, oxo, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl;
• or, R5 and R6 together with the carbon atom to which they are attached form a cycloalkyl or heterocyclyl, wherein the cycloalkyl or heterocyclyl is optionally further substituted by one or more substituents selected from the group consisting of halogen, amino, nitro, cyano, hydroxy, thiol, carboxy, ester group, oxo, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl;
• Ra and Rb are each independently selected from the group consisting of hydrogen, halogen, hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl, wherein the alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl are each optionally further substituted by one or more substituents selected from the group consisting of halogen, amino, nitro, cyano, hydroxy, thiol, carboxy, ester group, oxo, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl;
• or, Ra and Rb together with the nitrogen atom to which they are attached form a nitrogen-containing heterocyclyl, wherein the nitrogen-containing heterocyclyl is optionally further substituted by one or more substituents selected from the group consisting of halogen, amino, nitro, cyano, oxo, hydroxy, thiol, carboxy, ester group, alkyl, alkoxy, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl and heteroaryl;
• m is an integer from 0 to 2.