Using CCOC(=O)c1c(Br)nn2c(-c3c(OC)cc(COC)cc3OC)csc12 to produce COCc1cc(OC)c(-c2csc3c(C(=O)O)c(Br)nn23)c(OC)c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.