bis(1,1-dimethylethyl) {3-{1-[(2,5-difluorophenyl)acetyl]-2,3-dihydro-1H-indol-5-yl}-7-[2-({[(phenylmethyl)oxy]carbonyl}amino)ethyl]furo[3,2-c]pyridin-4-yl}imidodicarbonate