3,5-Dioxa-8,15-diaza-4-phosphaeicosan-20-oic acid,4-[bis(1-methylethyl)amino]-1-cyano-19-[[4-[[[1,4-dihydro-2-[(2-methyl-1-oxopropyl)amino]-4-oxo-6-pteridinyl]methyl](trifluoroacetyl)amino]benzoyl]amino]-7-[[(4-methoxyphenyl)diphenylmethoxy]methyl]-6-meth