Mass spectrometry of organic compounds of the group V Elements: VI—A new type of amine fragmentation under electron impact

A new type of amine fragmentation under electron impact is elucidated for proline, sarcosine and aspartic acid derivatives and aminomethylphosphines of the general formula R₂NCH₂X. Ordinary α-cleavage affording the \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm R}_2 \mathop {\rm N}\limits^{\rm + } {\rm = CH}_{\rm 2} $\end{document} ion is suppressed by elimination of a neutral HX particle and [M - HX]⁺ ion formation, or M-HX neutral particle ejection and generation of an [HX]⁺ ion from [M]⁺˙. Such fragmentation is ensured by the presence of an α-heteroatom (N, O, P, S) in one substituent (X) and a CO₂R type delocalizing group in the α-position of the other substituent (R₂N).     

Cyclic hydroxamic acids derived from α-amino acids 1. Regioselective synthesis,structure, NO-donor and antimetastatic activities of spirobicyclic hydroxamic acids derived from glycine and DL-alanine

The reactions of glycine hydroxamic and DL-alanine hydroxamic acids with triacetonamine are chemoselective and afford 1-hydroxy-7,7,9,9-tetramethyl-1,4,8-triazaspiro[4.5]decan-2-one (3) and (±)-1-hydroxy-3,7,7,9,9-pentamethyl-1,4,8-triazaspiro[4.5]decan-2-one (4), respectively. The X-ray diffraction study showed that compound 3 crystallizes as a solvate with MeCN (1: 1). As shown by ESR measurements, spiro hydroxamic acids 3 and 4 are NO donors in in vitro biological systems. The NO-donor activity of compounds 3 and 4 was found to be substantially higher in the presence of DMSO. Homologue 4 is a stronger NO donor than 3. Compound 4 also exhibits high antimetastatic activity (81%) on the B16-melanoma model.