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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Mcant on May 29, 2013, 05:50:51 AM

Title: 1-akyl-n-pyridinium salts synthesis
Post by: Mcant on May 29, 2013, 05:50:51 AM

Hi all,

Could anyone help me with a synthetic route to a 1-akylpyridinium salts?
Alternatively to a more specific 1-butyl-3-methylpyridinium hexafluorophosphate, I'm looking for specific literature.

I'm thinking using 4-picoline + haloalkane, though can't find literature examples and if possible I don't want to do any "blind" chemistry.

thanks

Title: Re: 1-akyl-n-pyridinium salts synthesis
Post by: Dan on May 29, 2013, 06:15:49 AM

I'm not well versed in the ionic liquid literature, but I imagine you make this from 3-picoline (not 4-picoline) and a haloalkane followed by anion exchange (AgPF₆? There is probably a cheaper way...).

Alfa Aesar sell it (cheaper than AgPF₆).

http://www.alfa.com/en/gp100w.pgm?dsstk=H27496

Title: Re: 1-akyl-n-pyridinium salts synthesis
Post by: Mcant on May 29, 2013, 06:26:17 AM

Thanks, i realize this should also probably be in the organic forum as well so sorry about that, would KPF6 work instead of the silver compound?

I know it's commercially available but i'm trying to synth quite a few various ILs to try and drive down the costs before I go on to other research using them and just trying to develop some kind of rough method / plan at the mo.

Thinking of basing some on quat ammonium cations as well.

Oh well thanks for the input hopefully someone else may know of a source ;)

Title: Re: 1-akyl-n-pyridinium salts synthesis
Post by: Dan on May 29, 2013, 08:25:23 AM

Yes you can use KPF₆.

See for example: J. Fluor. Chem. 2008, 129(2), 108-111 (http://www.sciencedirect.com/science/article/pii/S002211390700320X)

Title: Re: 1-akyl-n-pyridinium salts synthesis
Post by: Babcock_Hall on May 29, 2013, 10:16:52 AM

Harjani et al., Green Chemistry 2009, 11, 83-90 looks to be related to your work.  They use several counterions including PF₆.  This article might be a follow-up:  http://pubs.rsc.org/en/Content/ArticleLanding/2008/GC/b800534f

In the supporting information of this paper, there is also some pertinent material:  Anion-Templated Assembly of Pseudorotaxanes: Importance of Anion Template, Strength of Ion-Pair Thread Association,
and Macrocycle Ring Size.  Mark R. Sambrook,† Paul D. Beer,*,† James A. Wisner,†,‡ Rowena L. Paul,†
Andrew R. Cowley,† Fridrich Szemes,† and Michael G. B. Drew§  J. AM. CHEM. SOC. 2005, 127, 2292-2302.

Title: Re: 1-akyl-n-pyridinium salts synthesis
Post by: Mcant on May 30, 2013, 04:49:34 PM

Both very helpful and rapid replies, thanks a lot guys!