1H-pyrrolo[2,3-b]pyridines. Part II. Fragmentation of some 1H-pyrrolo[2,3-b]pyridines induced by electron impact

Abstract

Measurements have been made of the mass spectra of 1H-pyrrolo[2,3-b]pyridine, of a number of its derivatives with alkyl- or aryl-substituents in the 1-, 2-, 3-, and 4-positions, and of compounds containing amino-, nitro-, nitroso-, and halogeno-substituents in the 3-position. In certain cases additional evidence such as accurate mass measurement, examination of the origin of metastable ions, and deuterium labelling has been used to confirm the proposed fragmentation pathways. The mode of decomposition for many of the compounds is best accounted for by the formation of naphthyridines and pyrido[2,3-d]pyrimidines as intermediates. Comparisons are drawn with the fragmentation pathways of analogous indoles.