Using O=C(Cl)c1c(F)c(F)c(F)c(F)c1Br, CCOC(=O)CC(=O)OCC to produce CCOC(=O)C(C(=O)OCC)C(=O)c1c(F)c(F)c(F)c(F)c1Br, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.