Synthese und Struktur von 2-Imino-1,3-dimethylimidazolin / Synthesis and Structure of 2-Imino-1,3-dimethylimidazoline

Abstract

Deprotonation of the 2-amino- 1,3-dimethylimidazolium salt 5 (obtained through methylation of 2-amino-l-methylimidazole (4)) by KH gives 2-imino-1,3-dimethylimidazoline 6. The trimethylsilylimino compound 14 is formed on the reaction of 6 with chlorotrimethylsilane in the ratio 2:1. Further reaction with chlorotrimethylsilane gives the silylated aminoimidazolium salt 15. The X-ray structures of 5 and 6 are reported.

Novel N-heterocyclic ylideneamine gold(i) complexes: synthesis, characterisation and screening for antitumour and antimalarial activity

“…Bond lengths and angles in the imine ligand are not significantly changed by gold(I) coordination and are comparable to those in 1,3-dimethyl-1,3-dihydro-imidazol-2-ylidineamine 13 and standard values for such bonds. 23 Contrary to 15 N NMR observations in solution, C N and C-N bond lengths differ significantly and do not testify to any substantial electron delocalisation over these bonds in the solid state.…”

“…Most signals in the NMR ( 1 H, 13 In the 13 C NMR spectra very small to no changes are observed for NCN carbon shifts upon complexation in the benzimidazole compounds, whereas a significant downfield shift (Dd 7.9-10.4) is observed in the thiazole based derivatives. In the case of the phenyl carbons of the benzazole ligands some carbons appear slightly downfield and others slightly upfield.…”

“…13 Their method entails alkylation of the endocyclic nitrogen atom of a 1-methyl-1H-imidazol-2-ylamine derivative with MeI to yield a cationic amino compound. The latter can then be readily converted to the corresponding ylideneamine by deprotonation with potassium hydride.…”

Synthese und Eigenschaften von 2-Cyanimino-l,3-dimethylimidazolin [1] / Synthesis and Properties of 2-Cyanimino-l,3-dimethylimidazoline [1]

“…Durch Umsetzung des von uns früher beschrie benen 2-Iminoimidazolins 2 [5] mit Bromcyan und nachfolgende Abtrennung des hierbei gebildeten Imidazoliumbromids läßt sich 3 in guten Ausbeu ten in Form farbloser, mäßig hygroskopischer Kri stalle gewinnen. Im 13C-NM R-Spektrum ist die Si gnallage von C4,5 mit 115.6 ppm gegenüber 2 (111.4 ppm [5]) geringfügig zu hohem Feld ver schoben; C = N erscheint bei 124.0 ppm.…”

“…Im 13C-NM R-Spektrum ist die Si gnallage von C4,5 mit 115.6 ppm gegenüber 2 (111.4 ppm [5]) geringfügig zu hohem Feld ver schoben; C = N erscheint bei 124.0 ppm. Das C2 zugehörige Signal haben wir in Lösung nicht gefun-dort führt der gewinkelte Bau des exozyklischen den.…”