You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[2-(5-chloro-2-methoxyanilino)-2-oxoethyl]-N-methyl-1-(thiophene-2-carbonyl)piperidine-3-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C21H24ClN3O4S
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