Method for preparing pyrimidone heteroaryl derivative and intermediate of pyrimidone heteroaryl derivative

A method for preparing a compound of formula (I) or a stereoisomer thereof, wherein the method comprises reacting a compound of formula (III), a salt thereof or a stereoisomer thereof, with a compound of formula (II) or a salt thereof to obtain the compound of formula (I):

• wherein:
• G is C, D and E are N;
• R1 is selected from the group consisting of alkyl, cycloalkyl, heterocyclyl, aryl, heteroaryl and —OR5, wherein the alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl are each independently and optionally further substituted by one or more substituents selected from the group consisting of halogen, cyano, nitro, alkyl, haloalkyl, hydroxyalkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, —OR5, —C(O)OR5, —OC(O)R5, —NHS(O)mR5, —C(O)R5, —NHC(O)R5, —NHC(O)OR5, —NR6R7, —OC(O)NR6R7, —C(O)NR6R7, —NHC(O)NHR5 and —NHC(O)NHOR5;
• R2 is alkyl, wherein the alkyl is further substituted by one or more substituents selected from the group consisting of aryl and heteroaryl, wherein the aryl and heteroaryl are optionally further substituted by one or more substituents selected from the group consisting of halogen, alkyl, haloalkyl, cyano, nitro, —C(O)OR5, —C(O)NR6R7, —OC(O)NR6R7, —OR5, —NHS(O)mR5, —NHC(O)R5 and —NR6R7;
• R3 is alkyl;
• R4 is selected from the group consisting of hydrogen, cycloalkyl, heterocyclyl, aryl, heteroaryl, —OR5, —NR6R7 and —NR6S(O)mR5, wherein the cycloalkyl, heterocyclyl, aryl and heteroaryl are optionally further substituted by one or more substituents selected from the group consisting of halogen, oxo, alkyl, haloalkyl, hydroxyalkyl, —OR5, —C(O)OR5, —OC(O)R5, —NR7S(O)mR5, —S(O)mR5, —C(O)R5 and —NHC(O)R5;
• R5 is selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl, wherein the alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl are each independently and optionally further substituted by one or more substituents selected from the group consisting of alkyl, halogen, hydroxy, alkoxy, haloalkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxy and alkoxycarbonyl;
• R6 and R7 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl, wherein the alkyl, cycloalkyl, heterocyclyl, aryl and heteroaryl are each independently and optionally further substituted by one or more substituents selected from the group consisting of alkyl, halogen, hydroxy, alkoxy, haloalkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxy and alkoxycarbonyl;
• or, R6 and R7 together with the nitrogen atom to which they are attached form a heterocyclyl, wherein the heterocyclyl contains one or more heteroatoms selected from the group consisting of N, O and S(O)m, and the heterocyclyl is optionally further substituted by one or more substituents selected from the group consisting of alkyl, halogen, hydroxy, alkoxy, haloalkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxy and alkoxycarbonyl;
• Ra is alkyl, wherein the alkyl is optionally further substituted by one or more substituents selected from the group consisting of alkyl, halogen, hydroxy, alkoxy, cycloalkyl, heterocyclyl, aryl, heteroaryl, carboxy and alkoxycarbonyl;
• m is 0, 1 or 2;
• and
• n is 1, 2, 3 or 4.