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system
Provide the molecular formula for the IUPAC named substance ethyl 5-(4-acetyloxyphenyl)-7-methyl-2-(1-methyl-2-oxoindol-3-ylidene)-3-oxo-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate .
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C27H23N3O6S
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