Identification of the pyrolysis products of some aromatic-amines using microwave spectroscopy

The pyrolysis products of some aromatic amines have been identified using microwave spectroscopy. Aniline is found to produce 1-cyanocyclopenta-1,3-diene, N-methylaniline a mixture of 1-cyanocy-clopenta-1,3-diene and benzonitrile, N,N-dimethylaniline produces benzonitrile, and N,N-dimethylpyridine-2-amine produces pyridine. In the pyrolysis of N-methylaniline the proportion of 1-cyanocyclopenta-1,3-diene to benzonitrile is estimated to be 4 : 1 from the integrated relative intensities of the low-resolution microwave band spectra of the two substances.