Using CC(=O)c1c(Cl)cccc1Cl, O=Cc1c(Cl)cccc1Cl to produce O=C(C=Cc1c(Cl)cccc1Cl)c1c(Cl)cccc1Cl, please predict the solvent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.