You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl (2S)-2-[5-(4-bromo-3-prop-1-ynylphenyl)-1H-imidazol-2-yl]pyrrolidine-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H24BrN3O2
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