Using O=C(OCC1c2ccccc2-c2ccccc21)ON1C(=O)CCC1=O, NC1(C(=O)O)COC1 to produce O=C(NC1(C(=O)O)COC1)OCC1c2ccccc2-c2ccccc21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.