Prostacyclin receptor agonist

A compound represented by formula (I), an isomer or a pharmaceutically acceptable salt thereof,

• wherein,
• n is 1 or 2;
• R1 is H or F;
• each of R2 is independently selected from the group consisting of H, OH, NH2, halogen, C1-6 alkyl and C1-6 heteroalkyl, wherein C1-6 alkyl and C1-6 heteroalkyl are optionally substituted by one, two or three of Rb;
• each of Rb is independently selected from the group consisting of F, Cl, Br, I, OH and NH2;
• R3 is selected from the group consisting of H, OH, NH2, halogen, C1-6 alkyl and C1-6 heteroalkyl, wherein C1-6 alkyl and C1-6 heteroalkyl are optionally substituted by one, two or three of Rc;
• each of Rc is independently selected from the group consisting of F, Cl, Br, I, OH and NH2;
• R4 is selected from the group consisting of OH, C1-6 alkoxy and C1-6 alkyl-S(═O)2—NH—, wherein C1-6 alkoxy and C1-6 alkyl-S(═O)2—NH— are optionally substituted by one, two or three of Rd;
• each of Rd is independently selected from the group consisting of F, Cl, Br, I, OH and NH2;
• ring A is a phenyl or a 5- to 6-membered heteroaryl;
• ring B is a phenyl, a 5- to 6-membered heteroaryl, a C3-6 cycloalkyl or a 3- to 6-membered heterocycloalkyl;
• T1 is N or CH;
• T2 is N or CH;
• T3 is N or CH;
• T4 is N or C(R5);
• T5 is N, CH or C;
• R5 is selected from the group consisting of H, OH, NH2, halogen, C1-6 alkyl and C1-6 heteroalkyl, wherein C1-6 alkyl and C1-6 heteroalkyl are optionally substituted by one, two or three of Re;
• each of Re is independently selected from the group consisting of F, Cl, Br, I, OH and NH2;
• each of C1-6 heteroalkyl, 3- to 6-membered heterocycloalkyl and 5- to 6-membered heteroaryl respectively contains one, two or three of heteroatoms or heteroatomic groups independently selected from the group consisting of —O—, —NH—, —S— and N.