Sciencemadness Discussion Board

Hydration of Nitriles to Amides

Rich_Insane - 1-9-2013 at 16:47

Hi guys,

I think there has probably been a thread discussing this particular procedure, because I found the primary reference in the SM library. I want to make a modification to this procedure.

The primary reference I am referring to is "SYNTHETIC COMMUNICATIONS, 20(10), 1445-1451 (1990)." I have attached it to this post. In this article, sodium percarbonate (aka oxygen bleach) in acetone-water is used to transform various nitriles to amides. My question is whether DMSO can be used as a reaction solvent or not. Another reference (Efficient Conversion of Nitriles to Amides Using Basic Hydrogen Peroxide) uses K2CO3 in DMSO with 30% H2O2 (added dropwise) to achieve the same goal.

The reason I want to use DMSO is that I accidentally ordered DMSO instead of acetone, but now that I think about it, I'm curious whether DMSO will work. I don't see why DMSO couldn't substitute for acetone water. Even if the product is soluble in DMSO, I plan to quench the reaction with cold water (the amide in question is very insoluble in water). One potential worry of mine is the formation of dimethyl sulfone. The other reference I looked at found that dimethyl sulfone was detected via GC. I am not sure whether I should be worried about this or not. I plan to follow the primary reference word for word except for the part about using acetone-water.

On another note, I have tried using 3% H2O2 and NaOH per Vogel to perform this reaction, but I have had poor yields. I attribute this more to the fact that I have dilute H2O2 and cannot regulate the temperature easily (I use a cooking stove) and not Vogel itself.

EDIT: Forgot to add the attachment :D

[Edited on 2-9-2013 by Rich_Insane]

This file has been downloaded 569 times

Mesa - 2-9-2013 at 02:29

While I realise this is somewhat off-topic, what is the meaning of the claus 'very insoluble in water.' I've not had any formal education in chemistry so some technical phrasing still escapes me, however from what I understand, a compound is either soluble in a specific solvent, or it isn't(followed by grading of solubility i.e. slightly soluble etc.)

Rich_Insane - 2-9-2013 at 09:35

The compound is sparingly soluble in water at room temperature and soluble in water at 100oC, hence making water an excellent recrystallization solvent.

sonogashira - 2-9-2013 at 13:16

It says in the paper that you attached:

On dissolution in water, one equivalent of sodium percarbonate releases one and one-half equivalents of hydrogen peroxide.23

Perhaps you could use it to make a 30% solution of H2O2?

Rich_Insane - 2-9-2013 at 20:31


Perhaps you could use it to make a 30% solution of H2O2?

Yes, this is a very good use of sodium percarbonate (or the potassium equivalent) I think, especially if you're OK with alkaline peroxide. I would order 30% H2O2 (for other experiments), but it's very expensive to ship. I'm still looking for OTC sources in the area, but at the moment, I think the percarbonate salt is the way to go for this experiment due to the dirt cheap price of sodium percarbonate.

sonogashira - 2-9-2013 at 23:06

If you add it to water immediately before adding it drop-wise to your DMSO solution, you would replicate the "Efficient Conversion of Nitriles to Amides Using Basic Hydrogen Peroxide" experimental almost precisely. You could perhaps use a slurry if it is not possible to get the H2O2 solution as concentrated as you desire, since any excess would react with water in-situ. It would be worthwhile to attempt on a small scale, I should think.

[Edited on 3-9-2013 by sonogashira]