CPC C07D 491/22 (2013.01) | 17 Claims |
1. A compound or a pharmaceutically acceptable salt thereof, wherein the compound has the structure of formula (i):
wherein,
a is 0 or 1;
the carbon atoms marked with p1* and p2* each is asymmetric center, and the asymmetric center is S configured, R configured or racemic;
L1 is selected from C1-6 alkylene, which is unsubstituted or substituted with one substituent selected from halogen, —OH and —NH2;
M is —CH2—, —NH— or —O—;
L2 is C1-3 alkylene;
R1 is Cl; and
R2 is F.
|