You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[6,21-ditert-butyl-23-[4-(2,3,4,6,7,8-hexahydropyrimido[1,2-a]pyrimidin-1-yl)butanoyl]-2,25-dioxa-10,17-diazoniahexacyclo[15.8.0.01,10.03,8.011,16.019,24]pentacosa-3(8),4,6,9,17,19(24),20,22-octaen-4-yl]-4-(2,3,4,6,7,8-hexahydropyrimido[1,2-a]pyrimidin-1-yl)butan-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C51H70N8O4+2
assistant