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 ethyl 2-[[2-[(1-methyl-[1,2,4]triazolo[4,3-a]quinoxalin-4-yl)sulfanyl]acetyl]amino]benzoate into its molecular formula.
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C21H19N5O3S
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