Using CCOC(=O)C(=O)CBr, COc1cc(OC)c2c(CNC(=O)OC(C)(C)C)ncc(NC(N)=S)c2c1 to produce CCOC(=O)c1csc(Nc2cnc(CNC(=O)OC(C)(C)C)c3c(OC)cc(OC)cc23)n1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.