Using CN(C(=O)OC(C)(C)C)C(CCN1C(=O)c2ccccc2C1=O)C(=O)O to produce CN(C(=O)OC(C)(C)C)C(CCN)C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.