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 4-[(7-chloro-2,3,4,5-tetrahydro-1H-3-benzazepin-6-yl)oxy]-1-pyridin-2-ylbutan-1-one into molecular formula.
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C19H21ClN2O2
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