Using CCOC(=O)C(C(=O)O)C(C)(C)C, Nc1n[nH]c(=S)s1 to produce CCOC(=O)C(C(=O)Nc1n[nH]c(=S)s1)C(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.