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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Juaqui on May 18, 2019, 07:43:32 AM

Title: Formation of thioamides
Post by: Juaqui on May 18, 2019, 07:43:32 AM

Hi,

I'm searching for the mechanism of formation of thioamides from nitriles and thioacetamide in presence of HCl.
I have been searching in lots of books but I cannot find anything  :-\ :'(
This is for the explanation of part of this molecule:

https://www.google.com.uy/search?hl=es-419&tbm=isch&source=hp&biw=1231&bih=562&ei=P-_fXPeUL8io5OUP9LeQkAI&q=febuxostat&oq=febuxostat&gs_l=img.3..0l10.115.299..1056...0.0..0.434.434.4-1...0....1..gws-wiz-img.....0.F23dRg38ENY#imgrc=Mg3gwB2NZcmriM:&spf=1558179651206

By the moment, the only I find is that thioacetamide/HCl is for the formation of H2S, but I don't know the mechanism of the reaction.

Thank you!

Title: Re: Formation of thioamides
Post by: AWK on May 18, 2019, 10:04:01 AM

Thioacetamide is very expensive.
Thiolysis of nitriles with hydrogen sulfide is usually performed with weak bases to promote reaction.

Title: Re: Formation of thioamides
Post by: Juaqui on May 19, 2019, 09:24:39 AM

Thanks for answering. But, which would be the mechanism?
I find a reference that may help me, but I cannot get the article:

Bagley, M.C.; Chapaneri, K.; Glover, C.; Merritt, E.A. Synlett 2004 2615.

Someone of you have this information and could send me it?

Thanks a lot!


 

Title: Re: Formation of thioamides
Post by: AWK on May 19, 2019, 10:37:41 AM

If you can write a mechanism for alkaline hydrolysis of nitriles, you can also write the mechanism for the thionation reaction of nitrile with ammonium sulfide or sodium hydrogen sulfide.

This publication is in Synlett and probably no mechanism is given since its simplicity.