Using FC(F)(F)c1ccc(CBr)c(CBr)c1, CCOC(=O)CC(=O)OCC to produce O=C(O)C1(C(=O)O)Cc2ccc(C(F)(F)F)cc2C1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.