You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 3-(methoxymethyl)-N-[(2R)-2-methyl-3-oxo-4H-1,4-benzoxazin-6-yl]-1-benzofuran-2-carboxamide ?
user
C20H18N2O5
assistant