Experiment 8: Reactions of Nitrogen Functional Groups

N-functional group transformations

Due Dates:

16-Nov/17-Nov A
30-Nov/01-Dec B


Chemical Safety Information:

Reagents and Solvents
ortho-vanillin para-toluidine ethanol
sodium borohydride acetic acid acetic anhydride
deuterated chloroform


Experimental 1H-NMR Spectra:

N-functional Groups 1H-NMR 09-Nov-2015

N-functional Groups 1H-NMR 10-Nov-2015

N-functional Groups 1H-NMR 18-Nov-2015

N-functional Groups 1H-NMR 19-Nov-2015


p-toluidine 1H-NMR Spectrum


o-vanillin 1H-NMR Spectrum



imine product 1H-NMR Spectrum


amide product 1H-NMR spectrum

Sample Amide Product (not available for submission for credit)

Stock FID Amide Product (available for submission for credit, see laboratory manual for details)

Stock IR of Imine and Amide Products (available for submission for credit, see laboratory manual for details)

Frequently Asked Questions:

Q1) Why is the imine so brightly colored while the aldehyde and amine starting materials are not?

A1) Most organic compounds are not brightly colored, but the imine formed in this reaction is a chromophore with a bright orange.  Color in imines and other organic chromophores can arise from an absorption of a photon to promote an electron from a π to π* orbital or a lone pair (n) to π* orbital.  The energy of the photon is related to the HOMO-LUMO gap which generally decreases with increased conjugation leading to a red shift in the absorption as the conjugation increases.