Using CCOC(=O)c1cn(CCBr)c2c(F)c(F)c(F)c(C)c2c1=O to produce C=Cn1cc(C(=O)OCC)c(=O)c2c(C)c(F)c(F)c(F)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.