Thieno[2,​3-​b]​pyridine-​5-​carboxylic acid, 7-​[(2,​6-​difluorophenyl)​methyl]​-​4,​7-​dihydro-​2-​[4-​[(2-​methyl-​1-​oxopropyl)​amino]​phenyl]​-​3-​[[methyl(phenylmethy​l)​amino]​methyl]​-​4-​oxo-​, 1-​methylethyl ester