Organic mass spectrometry—X. Electron impact fragmentations of alkylthio group in 2-alkylthio-5-aminothiazolo[5,4-d] pyrimidines

✍ Scribed by A. Tatematsu; S. Sugiura; S. Inoue; T. Goto

• Publisher: John Wiley and Sons
• Year: 1968
• Tongue: English
• Weight: 415 KB
• Volume: 1
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210010204

✦ Synopsis

In order to discuss hydrogen transfer in the skeletal fragmentation of thioethers on electron impact, mass spectra of a series of 2-n-alkylthio-5-aminothiazolo[5,4-d]pyrimidines have been determined. To aid the interpretation of the hydrogen migration, deuterium-labeled compounds which are substituted with deuterium in each position of 2-n-butylthio-5-aminothiazolopyrimidines were studied. By correlation of the spectra obtained from such labeled compounds, the initial hydrogen migration in the fragmentation to produce [M -SH], [MS -CH,] and m/e 184 ions is concluded to be as follows: migration of the a-hydrogen atom to the sulfur induces formation of the [M -SH] ion; migration of the B-hydrogen atom to the sulfur or nitrogen atom by a McLafferty rearrangement induces formation of the m/e 184 ion; and migration of y-hydrogen atom to the sulfur induces formation of the [M -SCH,] ion.