Using CCOC(=O)CC[C@H](N)C(=O)OCC, Nc1nc2ccc3c(Nc4ccc(C(=O)O)cc4)cccc3c2c(=O)[nH]1 to produce CCOC(=O)CC[C@H](NC(=O)c1ccc(Nc2cccc3c2ccc2nc(N)[nH]c(=O)c23)cc1)C(=O)OCC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.