If you're trying to repeat the reaction, I'd recommend following the procedure as outlined in the (original) paper which you're trying to copy as closely as your resources will allow you. If you're still burning with curiosity, get scientific on it: try a couple of solvents and solvent mixtures and see how yield varies. Look up the mechanism and try to rationalize your results in terms of solubility of reactive species and stabilization of transition states. I mean, how long does it take to run one of these in the first place?