Using CCOC(CCCN)OCC, CC(C)(S)[C@H](NC(=O)OCc1ccccc1)C(=O)O to produce CCOC(CCCNC(=O)[C@@H](NC(=O)OCc1ccccc1)C(C)(C)S)OCC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.