7-[5-[[3-[3-[[2-Amino-4-(trifluoromethoxy)phenyl]amino]-3-oxopropyl]cyclobutyl](1-methylethyl)amino]-3,4-O-(1-methylethylidene)-β-L-ribofuranosyl]-N-[(2,4-dimethoxyphenyl)methyl]-7H-pyrrolo[2,3-d]pyrimidin-4-amine