| 摘要 |
The invention provides compounds of formula (I) wherein Ris a group of formula (II) or (IIa) or (IIIb) and R, R, R, R, a, b and X are as defined in the specification, a process for their preparation, pharmaceutical compositions containing them, a process for preparing pharmaceutical compositions, their use in therapy and intermediates of use in their preparation (I), (II), (IIIa), (IIIb)., (I), (II), (IIIa)(IIIb). |
