You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the compound with this IUPAC name 1,4-dioxa-8-azaspiro[4.5]decan-8-yl-[2-methyl-6-(2-phenylethylamino)pyrimidin-4-yl]methanone ?
user
C21H26N4O3
assistant