Using O=C(O)CC(O)(CC(=O)O)C(=O)O, C[C@H](c1ccccc1)N1C[C@@](C)(NC(=O)OC(C)(C)C)CC1=O to produce C[C@H](c1ccccc1)N1C[C@@](C)(N(C)C(=O)OC(C)(C)C)CC1=O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.