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Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: sharbeldam on June 05, 2021, 05:26:10 AM

Title: Spectroscopy question [amide vs vinylic hydrogens]
Post by: sharbeldam on June 05, 2021, 05:26:10 AM

Compound X -> C9H15NO2 (molecular mass 169g/m) undergoes hydrolysis to produce Y (72g/mol) and Z (115gr/mol)

I'm given H-NMR and IR of X and IR of Y, in H-NMR OF X the number of hydrogens from right to left is (6->3->2->4)
Z has peaks in 1715/3290/3350 in IR.

if we look at H-NMR of X, there are 4 hydrogens in the range of 5-7, these arent aromatic but vinylic and maybe the last one of them is amide H? it's so hard to tell but this is my try, am i right?

Title: Re: Spectroscopy question [amide vs vinylic hydrogens]
Post by: Orcio_87 on June 05, 2021, 10:18:21 AM

Right.... =C-H and -N-H are the most shifted H⁺ in NMR spectrum.

Title: Re: Spectroscopy question [amide vs vinylic hydrogens]
Post by: Babcock_Hall on June 06, 2021, 03:45:26 PM

In my experience amide and related NH hydrogens can vary considerably in chemical shift, partially owing to hydrogen bonding.  This can make assigning them a little tricky.