You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule [(1S)-1-(5,6-dimethyl-4-oxo-3H-thieno[2,3-d]pyrimidin-2-yl)ethyl] 4-methyl-3-nitrobenzoate into molecular formula.
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C18H17N3O5S
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