You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
propan-2-yl 4-(5-bromo-2,3-dimethoxyphenyl)-6-butyl-2-oxo-3,4-dihydro-1H-pyrimidine-5-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H27BrN2O5
assistant