19. A compound of claim 1, wherein said compound is selected from the group consisting of: (3R,4R)-1-(2,2,2-Trifluoro-ethyl)-pyrrolidine-3,4-dicarboxylic acid 3-[(4-chloro-phenyl)-amide] 4-{[2-fluoro-4-(2-oxo-2H-pyridin-1-yl)-phenyl]-amide}, (3R,4R)-1-(2,2-Difluoro...