2-{4-[(4S,5R)-2-[5-Chloro-4-(cyano-dimethyl-methyl)-2-ethoxy-phenyl]-4,5-bis-(4-chloro-phenyl)-4,5-dihydro-imidazole-1-carbonyl]-piperazin-1-yl}-N-(2-methoxy-1-methyl-ethyl)-acetamide