Compound as atr kinase inhibitor

A compound of formula I-a:

• or a pharmaceutically acceptable salt, ester, isomer, solvate, prodrug or isotopically labeled compound thereof,
• wherein:
• R1 is selected from hydrogen, deuterium, cyano, halogen, and substituted or unsubstituted hydroxyl, amino, C1-6 alkyl, C1-6 alkoxy, 3- to 7-membered cycloalkyl, 3- to 7-membered heterocycloalkyl, guanidino, ureido, amido, aminosulfonamido, sulfonamido, and HN—C(═NH)—C1-6 alkyl;
• R2 and R5 are each independently selected from hydrogen, deuterium, halogens, C1-6 alkyl, amino and
• C1-6 alkoxy;
• or R1 and R2 together with the atoms to which they are attached form a 5 to 6-membered heteroaryl or heterocyclic group containing 1 to 3 atoms selected from oxygen, nitrogen and sulphur, said 5 to 6-membered heteroaryl or heterocyclic group having 0 or 1 methylene group on its ring optionally substituted with —C(═O)— or —C(═NR7)—;
• if present, each R3 is independently selected from hydrogen, deuterium, halogen, C1-6 alkyl and C1-6 alkyl substituted with a substituent selected from cyano, amino, hydroxy, halogen, C1-6 alkyl and C1-6 alkoxy;
• R4 is selected from hydrogen, deuterium, C1-6 alkyl, 3- to 7-membered cycloalkyl, 3- to 7-membered heterocycloalkyl, C1-6 alkylamino, and (C1-3 alkyl)2amino;
• or R4 and R5 together with the atoms to which they are attached form a 5- to 7-membered heterocyclic group containing 1 to 3 atoms selected from oxygen, nitrogen and sulphur, said 5- to 7-membered heterocyclic group optionally substituted with a substituent selected from deuterium, hydroxyl, C1-6 alkyl, halogen, C1-6 alkoxy and C1-6 alkylamino;
• said heterocyclic group having 1 to 3 methylene groups on its ring optionally substituted by —SO2—, —SO(═NR7)—, —SO2NH—, —CO—, —C(═O)NH—, C1-6 alkylamino, or 3- to 6-membered cycloalkylamino;
• wherein said C1-6 alkylamino or 3- to 6-membered cycloalkylamino has 0 to 2 methylene groups optionally substituted with oxygen, nitrogen, sulfur, or C1-3 alkylamino;
• if present, each R6 is independently selected from hydrogen, deuterium, halogen, amino, C1-6 alkoxy, C1-6 alkyl and C1-6 alkyl substituted with cyano, amino, hydroxy, halogen, C1-6 alkyl or C1-6 alkoxy;
• Q1 is selected from C1-6 alkylene, —CO—, amino, —SO—, —SO2—, —C(═NR7)—, and 3- to 7-membered heterocyclic group, wherein said C1-6 alkylene has 0 to 4 methylene groups optionally substituted with amino, —CO—, —SO—, —SO2 or —C(═NR7)—;
• Q2 is selected from —SO2—, SO, —SO(═NR7)—, —SO2NR7— and —CO—;
• each R7 is independently selected from hydrogen, deuterium, C1-6 alkyl, cyano, 3- to 7-membered cycloalkyl, 3- to 7-membered heterocyclic group, C1-6 alkoxy, C1-6 alkylamino, and C1-6 alkyl, 3- to 7-membered cycloalkyl and 3- to 7-membered heterocyclic group substituted by a substituent selected from cyano, amino, hydroxyl, halogen, C1-6 alkyl, and C1-6 alkoxy;
• and
• each of n1, n2 and n3 is any integer from 0 to 2.