I perform a reaction of a 4,4'-bipyridine N-monosubstituted derivative with an alkyl-bromide substrate (Menschutkin type reaction). For more details see the attached file. The reaction works in DMF but has a series of disadvantages. MeCN is not good do to low solubility of the alkyl bromide substrate that I used.... A more elegant and easy way will be if the reaction was performed in water or mixture alcohol/water as solvent. Does anyone have an idea or can suggest some literature regarding solvent effect in Menschutkin reaction?
Yes, this rxn is typically run in polar aprotic solvents, but can also be run in aqueous mixtures. However, solubity of the reagents can be a limiting factor.
See the following:
(1)https://workspace.imperial.ac.uk/centreforprocesssystemsengineering/Public/Autumn%20Consortium%20Meeting%202011/Student%20Poster%20and%20Presentations/(7)Ganase,%20Zara-Poster.pdf
(2) http://pubs.acs.org/doi/abs/10.1021/jo01041a035
Salut! I think it's worth a shot. More energetic conditions and longer time might be required, but it might/should work. Try it on a small scale first. Succes.
I think the reaction can occur if the reactants are soluble in water or water/EtOH mixture because polar media accelerate such type of reactions
The reaction process is accelerated by polar aprotic solvents and increased pressure and temperature. refer JOC. 2007, 72, p. 9663. for further literaure..
You can use Aliquat 336as a phase transfer catalyst, but perhaps its worth a shot to try using mixtures of solvents, like water/CH3CN, or MeOH, or EtOH..
Hi,
The reaction works well in Nitromethane. You can use methanol also. Better try with MeOH/ Water mixture. I foresee some solubility issues with water. For choosing the best solvent for the Menschutkin reaction please go through the below ling.
http://www.aidic.it/escape20/webpapers/481Struebing.pdf
The other replies are all informative and correct. It is sure that the protic solvent is good, but your alkyl bromide could give you prolems. The use of a phase transfer agent is good, using an alkyl-based surfactant could work but might lead to separation difficulties afterwards. Cyclodextrins can also be used to help solubility in aqueous-based polar solvents.
The solubility in water of my substrate alkyl bromide is slightly at room temperature but increase drastically with temperature. For example I get more then 600 mg/30 ml water after heating to 80°C. This is optimistic to start a reaction using water as solvent. Thanks a lot for useful answers!
Indeed, the reaction process is accelerated by polar aprotic solvents and increased pressure and temperature. Hence, you might have to tune your reaction conditions to account for the solubility problems. Good luck!
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