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Topic: H-NMR analysis  (Read 3491 times)

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Offline Cryptonic

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H-NMR analysis
« on: October 29, 2012, 04:22:04 PM »
Hello,

This is my first post on this site, so nice to meet you all.

I took an H-NMR spectrum of trans-Methyl cinnamate the other week, and upon examining it, there were two peaks that I just can't account for.

Here is the spectrum:


This is my data so far:
3.80ppm   RCOOCH3
6.45ppm   R=CHCOOR
7.29-7.65ppm   C6H5R
7.69ppm   PhCH=R

However, I can't account for the peaks about 5.25ppm and 8.35ppm.


My procedure:
1. refluxed cinnamic acid with SOCl2 to form cinnamoyl chloride.
2. Removed excess SOCl2 via distillation and 2 washes of hexane, which was also distilled off.
3. refluxed cinnamoyl acid in CH2Cl2 with pyridine and methanol.
4. Separated with NaCHO3 in separatory funnel into anhydrous CaCl2.
5. removed excess CH2Cl2 via distillation.

So, what caused the peaks about 5.25ppm and 8.35ppm?
At first, I assumed it could be pyridine, due to the 8.35 peak, but I crossed that one off the list
Any help would be fantastic,

Thank you,
Cryptonic

Offline Cryptonic

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Re: H-NMR analysis
« Reply #1 on: October 29, 2012, 08:33:46 PM »
Only an Aromatic and an Amide would cause a peak around 8.3, wouldn't it?

Offline Cryptonic

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Re: H-NMR analysis
« Reply #2 on: October 29, 2012, 10:09:35 PM »
Alright, I'm just going to account the 8.35 and 5.25 shift to pyridine. It's the only thing I can think of!
Thanks anyways guys, let's hope it doesn't cost me too much if it's wrong.

Offline discodermolide

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Re: H-NMR analysis
« Reply #3 on: October 30, 2012, 01:14:59 AM »
looks like pyridine and dichloromethane.
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