Patent ID: 8889692

Claim:
A compound of formula (IA), as a free base or a pharmaceutically acceptable salt thereof wherein: R 1 and R 2 are independently selected from H, (C 1 -C 4 )alkyl and F; as to R 22 and R 23 : R 22 and R 23 are each independently selected from H and (C 1 -C 6 )alkyl; or R 22 and R 23 , together with the carbon atom to which they are both attached form a (C 3 -C 4 )cycloalkyl; R 26 is (C 1 -C 6 )alkoxy optionally substituted with NR 34 R 35 ; and R 34 and R 35 are independently selected from H and (C 1 -C 6 )alkyl wherein said (C 1 -C 6 )alkyl may be optionally substituted by OH.