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Topic: H NMR spec help  (Read 15255 times)

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Offline Exproxsul

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Re: H NMR spec help
« Reply #15 on: June 14, 2012, 09:22:04 AM »
K here we go, i redid the integration calculations. benzene ring has 5 protons,  the quintet at 2.5-3 has 1 and the doublet at 1 ppm has 6 protons.
The nmr spec is attached below.

The aromatic region has 5 protons, it does not mean that the phenyl ring has 5 attached to it, look at the symmetrical pattern, I suggested a 1,4 disubstituted phenyl ring.

i tried out all different 1,4 substituents , did not work out.

Offline discodermolide

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Re: H NMR spec help
« Reply #16 on: June 14, 2012, 09:32:30 AM »
K here we go, i redid the integration calculations. benzene ring has 5 protons,  the quintet at 2.5-3 has 1 and the doublet at 1 ppm has 6 protons.
The nmr spec is attached below.

The aromatic region has 5 protons, it does not mean that the phenyl ring has 5 attached to it, look at the symmetrical pattern, I suggested a 1,4 disubstituted phenyl ring.

i tried out all different 1,4 substituents , did not work out.

I simulated the NMR of the compound I think it is, the shifts differ slightly but don't worry about that, look at the patterns.
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Offline Exproxsul

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Re: H NMR spec help
« Reply #17 on: June 14, 2012, 09:38:46 AM »
4-(propan-2-yl)phenol im assuming that small peak is the OH?

Offline discodermolide

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Re: H NMR spec help
« Reply #18 on: June 14, 2012, 09:43:44 AM »
4-(propan-2-yl)phenol im assuming that small peak is the OH?

That's what I think it is, and the small peak is the OH, in your actual spectrum it is under the aromatic signals.
If you did an exchange with D2O the OH would become OD and the integration would change from 5 to 4.
Or you could expand the aromatic portion of the spectrum and then you would see it a bit clearer.
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Offline Exproxsul

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Re: H NMR spec help
« Reply #19 on: June 14, 2012, 09:45:49 AM »
4-(propan-2-yl)phenol im assuming that small peak is the OH?

That's what I think it is, and the small peak is the OH, in your actual spectrum it is under the aromatic signals.
If you did an exchange with D2O the OH would become OD and the integration would change from 5 to 4.
Or you could expand the aromatic portion of the spectrum and then you would see it a bit clearer.

Thank you very much for all the time and help you have given me. :) I really appreciate it.

Offline discodermolide

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Re: H NMR spec help
« Reply #20 on: June 14, 2012, 09:56:41 AM »
4-(propan-2-yl)phenol im assuming that small peak is the OH?

That's what I think it is, and the small peak is the OH, in your actual spectrum it is under the aromatic signals.
If you did an exchange with D2O the OH would become OD and the integration would change from 5 to 4.
Or you could expand the aromatic portion of the spectrum and then you would see it a bit clearer.

Thank you very much for all the time and help you have given me. :) I really appreciate it.

No problem  ;D
Development Chemists do it on Scale, Research Chemists just do it!
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