You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 2-[3-(2-chlorophenyl)prop-2-enoylamino]-5-(diethylcarbamoyl)-4-methylthiophene-3-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23ClN2O4S
assistant