Using CCBr, CCOC(=O)c1ccc(OC(F)F)c2oc3c(=O)[nH]ncc3c12 to produce CCOC(=O)c1ccc(OC(F)F)c2oc3c(=O)n(CC)ncc3c12, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.