“A Solvent-Free Oxidation of Alcohols in an Organic Laboratory” by John J. Esteb, Micheal W. Schelle, and Anne M. Wilson. Journal of Chemical Education, 80, p. 907 (2003)
Experiment Notes:
The procedure written for the oxidation of cyclohexanol to cyclohexanone can be easily adapted to methylcyclohexanol.
This is a smaller scale reaction than last week (0.00482 moles) so it may be advantageous to scale it up.
Work-up involves filtration and evaporation of the solvents – no distillation.
Positive
+ Alternative oxidation method that does not involve liquid-liquid separation
+ Solvent-free reactions generate good discussion of environmentally friendly reactions
Neutral
-/+ Why not grind alcohol into solid with the mortar and pestle?
-/+ An incomplete reaction was often had if students did not stir their reactant together sufficiently.
-/+ if there's no solvent why is reflux condensor necessary?
Negative
- Need quite a bit of solvent if you want to do a decent extraction of the product from the solid residue. This is rather inefficient and increases solvent consumption.
- Its hard to get the solid mass out of a round bottom.
- a mechanism is not given for the reaction.
Inquiry & Extension Ideas:
= A large variety of alcohols could be tried as substrates.
= A relatively simple experiment where modifications (amount of KMnO4-CuSO4-alcohol, reaction temperature, reaction time, etc...) could be made to study optimization strategies.