Using CCOC(=O)CC1OB(O)c2cc(Oc3nnc(Br)s3)cc(C)c21 to produce CCOC(=O)CC1OB(O)c2cc(Oc3nncs3)cc(C)c21, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.