Using COc1ccc(C(=O)CC(c2ccc(Br)cc2)C2CCC2)cn1 to produce O=C(CC(c1ccc(Br)cc1)C1CCC1)c1ccc(=O)[nH]c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.