How would I separate these solutions in methylene chloride (dichloromethane) as

Question

How would I separate these solutions in methylene chloride (dichloromethane) as they are all neutral:

benzil and 1,4-dibromobenzene

fluorene and 1,4-dibromobenzene

benzoin and 1,4-dibromobenzene

None are soluble in water. All are soluble in acetone, diethyl ether, and methylene chloride. They are all neutral, so I don't think the acids/bases listed can be used (unless I'm missing something). I know that 1,4-dibromobenzene is much more soluble in toluene than benzoin is, so I'm thinking this may be correct for that one, but I can't find solubilities for any of the other ones.

I have available: 1 M NaOH, 6 M NaOH, 1 M HCl, 1 M NaHCO3, Saturated sodium chloride, Diethyl ether, 95% ethanol, Methanol, Isopropyl alcohol, Acetone, Hexane, Toluene, Methylene chloride, Granular anhydrous sodium sulfate.

I'll need a high recovery and I will need to recrystallize for purification.

Any REAL help would be appreciated.

Explanation / Answer

you have to take a concentrated solution of benzil and 1,4-dibromobenzene (or

fluorene and 1,4-dibromobenzene, benzoin and 1,4-dibromobenzene

) in Methylene chloride, then add MeOH, DROP BY DROP. 1,4-dibromobenzene WILL REMAIN SOLUBLE IN THAT SOLVENT MIXTURE. BUT benzil (OR FLUORENE, BENZOIN) WILL BECOME INSOLUBLE AND PRECIPITATE WILL COME. YOU FILTER THE SOLUTION TO SEPARATE THE PRECIPITES. IN THAT WAY YOU CAN EASY SEPARATE THIS MIXTURES.

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