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Topic: N,N-Dietyl m-Toluamide purification.  (Read 5835 times)

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Offline xoggyux

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N,N-Dietyl m-Toluamide purification.
« on: March 27, 2010, 04:54:29 PM »
How would you purify a crude sample of N,N-Diethyl m-toluamide that was synthesized by adding diethylamine to m-toluic chloride (already neutralized by NaOH, therefore only N,N-Diethyl m-toluamide and diethylamine/chloride salt is in the mixture.)
Also how would you distingish a pure sample of the inpure one in an IR spectrum? I've got both spectrum, but honestly they look very similar with perhaps a couple of peaks different in the ~1500/~600 cm-1.
Thank you.

Offline sjb

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Re: N,N-Dietyl m-Toluamide purification.
« Reply #1 on: March 28, 2010, 10:41:06 AM »
How soluble is the amide in water? What about in organic solvent?

Offline xoggyux

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Re: N,N-Dietyl m-Toluamide purification.
« Reply #2 on: March 28, 2010, 11:02:49 AM »
Oh, I get it, since the amide cannot form hydrogen bonds while the amine can then the amide will stay in the organic phase while the amine will stay in the aqueous phase?
Does that sound right?

Offline sjb

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Re: N,N-Dietyl m-Toluamide purification.
« Reply #3 on: March 28, 2010, 11:41:20 AM »
Pretty much. Note that you no longer have an amine, but an ammonium salt which would be much more soluble than the neutral amine.

Offline xoggyux

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Re: N,N-Dietyl m-Toluamide purification.
« Reply #4 on: March 28, 2010, 03:24:24 PM »
yeah, I was actually thinking of that while at work :D. thank you.
Any idea about what peaks should I find in the crude IR spectrum vs the purified? they do look very similar (e.g. peaks at ~3000 for C-H, peaks at ~1650 and ~1450 for the toluene ring, but I cannot distinguish anything obvious that makes them different....

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