N-[9-[(1R,5R,7R,8S)-3-(3-Aminopropyl)-5-[[bis(4-methoxyphenyl)phenylmethoxy]methyl]-8-hydroxy-2,6-dioxa-3-azabicyclo[3.2.1]oct-7-yl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-2-methylpropanamide