Electron impact ionization mass spectrometry and tandem mass spectrometry of phenylalkylpyridazines

✍ Scribed by Ernst Pittenauer; Günter Allmaier; Erich R. Schmid; Wolfgang Stanek; Gottfried Heinisch

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 486 KB
• Volume: 26
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210260611

✦ Synopsis

The mass spectrometric fragmentation behaviour of pyridazine and four monosubstituted derivatives containing a phenylalkyl side-chnin (3-and dbenzylpyridazine, 3-and 4-Q-phenylethyl)pyridazine) was investigated. In the electron impact ionization mass spectra of the hubstituted compounds abundant [ M -HI + peaks are ohse~ed.

This allows a clear distinction

between 3-and Qsubstituted pyridaziaes, as the spectra of the latter isomers show only very weak [ M -HI + signals The stability of [ M -HI + ions derived from Ialkylpyridazines (deduced from only the very low abundance of further fragment ions) gives strong evidence for a cyclic structure of these ions. One fragmentation pathway typical of the parent pyridazine, the [ M -N, 1 fragmentation, was not detectable with any of the phenylalkylpyridazines investigated. Instead, loss of HCN, H,CN and N,H was ohserved. An interesting fragmentation, observed with 3-(2-phenylethyl)pyridazine, is the loss of 'CH, from the molecular ion and also from the [ M -HI + ion.