You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-N-[(2R)-butan-2-yl]-2-[[2-(2-chlorophenyl)acetyl]-[(3,4-dichlorophenyl)methyl]amino]propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H25Cl3N2O2
assistant