You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[1-(2,4-dimethylanilino)-1-oxopropan-2-yl] 2,3-dihydro-1-benzothiophene-2-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H21NO3S
assistant