The fragmentation behavior of differently substituted 2-amino-1,3,4-benzotriazepines

The mass spectra of eighteen 2-amino-1,3,4-benzotriazepines were recorded under electron ionization, and the fragmentation patterns were elucidated by metastable ion analysis and exact mass measurements. The most typical fragmentations were ring contraction reactions with the loss of nitrogen atoms at positions 3 and 4. Extensive rearrangement reactions took place as well. In these the substituted 2-amino group played an important role. Isomeric compounds were easily distinguished.