Using COc1ccc(CN(c2ccccc2)c2cc(Cl)nn3ccnc23)cc1, O=C=O to produce COc1ccc(CN(c2ccccc2)c2cc(Cl)nn3c(C(=O)O)cnc23)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.