Using O=C[C@@]1(O)CO[C@@H]2[C@H](Oc3nc4nc(-c5ccc(-c6ccccc6)cc5)c(Cl)cc4[nH]3)CO[C@@H]21 to produce OC[C@@]1(O)CO[C@@H]2[C@H](Oc3nc4nc(-c5ccc(-c6ccccc6)cc5)c(Cl)cc4[nH]3)CO[C@@H]21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.