Über die Bildung cyclischer Ionen und bicylischer Übergangszustände beim Zerfall substituierter α,ω‐Alkandiamine im Massenspektrometer. 23. Mitteilung über das massenspektrometrische Verhalten von Stickstoffverbindungen

Formation of cyclic ions and bicyclic transition states in the mass spectral decomposition of substituted α,ω‐alkanediamines. N‐Phenethyl‐N(4‐acetamidobutyl)‐ p ‐toluene‐sulfonamide ( 4 ) and its homologues were synthesized and the mass spectral behaviour investigated. After loss of a benzyl radical from the molecular ion two different fragmentation reactions are observed. The lower homologous members – namely compounds 1 , 2 and 3 – lose ketene by formation of cyclic ions ( Scheme 1 ). The higher homologues of this series of compounds ( 4 , 5 , 6 ) show a pronounced (to 18% ∑ 50 ) loss of p ‐toluene sulfonic acid. This decomposition reaction proceeds presumably through a bicyclic transition state ( Scheme 3 ).