Using O=C(O)Cc1c(-c2ccccc2)nn(-c2ccccc2)c1-c1ccccc1, CO to produce COC(=O)Cc1c(-c2ccccc2)nn(-c2ccccc2)c1-c1ccccc1, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.