You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
propan-2-yl (2Z,5R)-5-(5-bromo-2-methoxyphenyl)-2-[(5-chloro-2-ethoxyphenyl)methylidene]-7-methyl-3-oxo-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H26BrClN2O5S
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