You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 4-butyl-9-[2-chloro-4-(trifluoromethyl)phenyl]-8,10-dihydropyrano[2,3-f][1,3]benzoxazin-2-one is given. What is its corresponding molecular formula?
user
C22H19ClF3NO3
assistant