Using OC1CCn2nc(-c3ccccn3)c(-c3ccnc4cc(Br)ccc34)c21 to produce O=C1CCn2nc(-c3ccccn3)c(-c3ccnc4cc(Br)ccc34)c21, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.