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 N-(3-butan-2-yl-1,1-dioxo-4-phenyl-1lambda6,2,4-benzothiadiazin-7-yl)furan-2-carboxamide ?
user
C22H21N3O4S
assistant