You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 2-[5-[2-(2,2,4,4-tetramethyl-3H-thiochromen-6-yl)ethynyl]pyrimidin-2-yl]acetic acid into its molecular formula.
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C21H22N2O2S
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