You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-hydroxy-2-propylpentyl)-3-methyl-4-oxo-6,7-dihydro-5H-1-benzofuran-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H27NO4
assistant