Using COc1c(C)c(Cc2ccc(O)c(C(=O)N3CCOCC3)c2)c(OC)c(OC)c1OC, CC(C)(C)OC(=O)CBr to produce COc1c(C)c(Cc2ccc(OCC(=O)OC(C)(C)C)c(C(=O)N3CCOCC3)c2)c(OC)c(OC)c1OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.