You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[1-(4-methylphenyl)sulfonylpyrrolidin-2-yl]-7-propan-2-yl-3,5,6,8-tetrahydropyrido[3,4-d]pyrimidin-4-one into its molecular formula.
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C21H28N4O3S
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