You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[4-(4-chlorophenyl)-2-(3-methoxypropyl)-6-oxopyrimidin-1-yl]-N-(2-hydroxy-2-methylpropyl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H26ClN3O4
assistant