Using CCOC(=O)Cc1cc(NCc2ccccn2)c2c(-c3ccccc3)csc2n1, CCOC(=O)OCC to produce CCOC(=O)C(C(=O)OCC)c1cc(NCc2ccccn2)c2c(-c3ccccc3)csc2n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.