Using COc1nc2cc(Cl)c(Cl)c(-c3ccncc3)c2nc1OC to produce O=c1[nH]c2cc(Cl)c(Cl)c(-c3ccncc3)c2[nH]c1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.