Using COc1ccc(C(=O)Nc2c(Cl)cncc2Cl)c2c3c(oc12)CN(C(=O)OC(C)(C)C)CC3 to produce COc1ccc(C(=O)Nc2c(Cl)cncc2Cl)c2c3c(oc12)CNCC3, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.