[Mpatas]

Hello to everyone,

I want to form the HCl salt of piperidine during the reduction of pyiridine. Since now, I have been doing that using CHCl3 in a big excess in ethanol but my supervisor doesn't like that because is not green enough. My second thought was to use a solution of HCl in methanol. I want your opinion and your suggestions.

Thanks

[TheUnassuming]

That could work. 
I have a few ideas but can you tell us more detail about the method/conditions you are using?  You are wanting to form the salt as the reaction proceeds rather than after completed? 

[Mpatas]

I reduce substituted pyridines to piperidines using PtO₂ as the catalyst under 3 bars pressure of Hydrogen gas. I normally do it in ethanol/Chloroform with 10/1 ratio and when the reaction is complete I just filter and evaporate to get the HCl salt of the piperidine. It does work but it's not green because I use Chloroform in a big excess.

[discodermolide]

So what it is it green! You can always re-cycle the chloroform!
There is no green chemistry.
If the reaction works well use it, to hell with the greenness of the process.