Spectral Problems

Spectra for the followng compounds are shown below (IR, 1H NMR, MS of p-bromophenacyl bromide (1) and crude acetate (2); IR and 1H NMR of p-toluenesulphonamide (3).

The following questions should be considered:
  1. What is the most likely impurity in the crude p-bromophenacyl acetate from the IR spectrum (Spectrum 4; it was prepared in aqueous ethanol)?
  2. Assign the major peaks (2 x C=O, 1 x C-0, Nujol) in this spectrum
  3. For the NMR and MS spectra of starting p-bromophenacyl bromide and product p-bromophenacyl acetate decide which spectra belong to which compound.
  4. Assign the peaks in these spectra, especially noting the bromine isotope patterns in the MS
  5. For more advanced discussions talk about the four lines in the aromatic region of the two NMR spectra (further examples where the lines converge may be found in the Aldrich library)
  6. Assign the peaks in the IR and NMR of p-toluenesulphonamide (note another AB in the aromatics)

Spectrum 1, IR p-bromophenacyl bromide

Spectrum 1

Spectrum 2, MS of p-bromophenacyl bromide/p-bromophenacyl crude acetate

Spectrum 1

Spectrum 3, 1H NMR for p-bromophenacyl bromide/p-bromophenacyl crude acetate

Spectrum 1

Spectrum 4, IR for p-bromophenacyl crude acetate

Spectrum 1

Spectrum 5, MS for p-bromophenacyl bromide/p-bromophenacyl crude acetate

Spectrum 1

Spectrum 6, 11H NMR for p-bromophenacyl bromide/p-bromophenacyl crude acetate

Spectrum 1

Spectrum 7 11H NMR for p-toluenesulphonamide

Spectrum 1

Spectrum 8. IR for p-toluenesulphonamide

Spectrum 1