Patent ID: 7462615

Claim:
A compound of formula (Ib): wherein, Ru is selected from the group consisting of CN, ═O, Hal, Alk, OAlk, OH, NRCN, C(CN)═C(OH)(OAlk), SR, NRR′, C(O)NRR′, Heterocycle, Aryl, Heteroaryl, and Cycloalkyl, wherein Alk, Aryl, Heteroaryl, Heterocycle, and Cycloalkyl are optionally substituted by Hal, NRR′, CN, OH, CF 3 , Aryl, Heteroaryl, or OAlk; R3, R4, R5, R6 are each identical or different and are independently chosen from the group consisting of H, OAlk, Alk, Hal, NRR′, CN, OH, OCF3, CF3, Aryl, and Heteroaryl; R and R′ are each identical or different and are independently selected from the group consisting of H and Alk, wherein Alk is optionally substituted by Hal, NRR′, CN, OH, CF 3 , Aryl, or Heteroaryl; or, their pharmaceutically acceptable salts, or their optical isomers, racemates, diastereomers or enantiomers.