Using CCOC(C)=O, COCCn1c(-c2ccc(C(C)C)cc2)nc2c(Br)c(Cc3ccccc3S(C)=O)cc(OC)c21 to produce COCCn1c(-c2ccc(C(C)C)cc2)nc2c(Br)c(Cc3ccccc3S(C)(=O)=O)cc(OC)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.