You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 2,4-difluoro-N-[4-oxo-4-[1-[3-(trifluoromethyl)phenyl]ethylamino]butyl]benzamide using the IUPAC nomenclature.
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C20H19F5N2O2
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