Using CCOC(=O)C(=O)c1csc(N)n1, C[C@H](NC(=O)OC(C)(C)C)C(=O)O to produce CCOC(=O)C(=O)c1csc(NC(=O)[C@H](C)NC(=O)OC(C)(C)C)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.