Using O=C(Cl)c1cccnc1, OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O to produce O=C(OC[C@@H](OC(=O)c1cccnc1)[C@H]1OC[C@H](OC(=O)c2cccnc2)[C@H]1OC(=O)c1cccnc1)c1cccnc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.