Using O=C1NC(=O)c2ccccc21, CC(C)(C)OC(=O)NC(C(=O)O)c1ccc(N)cc1 to produce CNc1ccc(C(NC(=O)OC(C)(C)C)C(=O)O)cc1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.