Patent ID: 11891405
Assignee: CHIA TAI TIANQING PHARMACEUTICAL GROUP CO., LTD
Field: Pharmaceuticals (Chemistry)
Classification: CPC C  A | IPC C

Claim 8:
9. The compound of formula (I), a stereoisomer thereof or a pharmaceutically acceptable salt thereof according claim 1, wherein Ra is independently selected from the group consisting of C2-6 alkynyl, C2-6 alkenyl, C1-6 alkyl, C3-6 cycloalkyl, (C1-6 alkyl)NH—, (C1-6 alkyl)2N—, 3- to 6-membered heterocycloalkyl, 5- to 10-membered heteroaryl and C6-10 aryl, wherein Ra is optionally substituted with (C1-3 alkyl)2N—, (C1-3 alkyl)NH—, hydroxy or amino.