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 2-[3-[(3R,6R)-5-amino-3,6-dimethyl-6-(trifluoromethyl)-2H-1,4-oxazin-3-yl]phenyl]-1-(5-methoxypyridin-2-yl)ethanone ?
user
C21H22F3N3O3
assistant