You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance ethyl 2-[2-methyl-3-oxo-6-(2-pyridin-2-yl-1,3-thiazol-4-yl)-1,4-benzoxazin-4-yl]acetate .
user
C21H19N3O4S
assistant