Using CC(=O)c1cc(Cl)c(C)c(Br)c1O, CC(C)(C)OC(=O)NCCO to produce CC(=O)c1cc(Cl)c(C)c(Br)c1OCCNC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.