You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-(2-chlorophenyl)ethyl]-2,6-dimethyl-3-oxo-4H-1,4-benzoxazine-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H19ClN2O3
assistant