1-Vinyl-4-imidazoline-2-thione

Lampl, Martin; Laus, Gerhard; Wurst, Klaus; Huppertz, Hubert; Schottenberger, Herwig

doi:10.1107/s241431461701207x

Cited by 2 publications

(1 citation statement)

References 15 publications

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“…Anyway, the final removal of the imidazole C2-proton is still lacking mechanistic clarification. For example, own experiments 16 showed that deprotonation of 1-vinylimidazole using strong bases, such as isopropylmagnesium chloride proceeds satisfactorily (with subsequent addition of elemental sulfur yielding 1-vinyl-4-imidazoline-2-thione, hereby confirming the desired attack at the C2-position). Upon addition of isolated arenediazonium tetrafluoroborates to 1-vinylimidazole solutions in THF, the reaction mixture immediately undergoes a red coloration, but, disappointingly, no N-vinylated phenylazoimidazole system could be straightforwardly isolated so far.…”

Section: Synthetic Considerationsmentioning

confidence: 93%

2-Arylazoimidazoles Revamped by Quarternization or Dimerization; Another Gain in Functionality of an Industrial Dyestuff Family by Task-Specific Side-Chain Substituents

Nerdinger¹,

Schottenberger²,

Neuner³

et al. 2022

HETEROCYCLES

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Based on [(E)-2-(4-fluorophenyl)diazenyl]-1H-imidazole,[210180-24-0], a versatile late stage intermediate for the divergent synthesis of direct dyes, a novel series of N,N`-disubstituted azoimidazolium salts was prepared. In particular, benzylation, 4-vinylbenzylation, phenacylation, sulfopropylation, ethylation, as well as propargylation allowed for the access of derivatives (1-6), which are useful for follow-up conversions, e.g. click reactions, or free radical polymerization. The compounds were routinely characterized spectroscopically. The diethylated tetrafluoroborate salt 5 was additionally analyzed by 19 F-NMR. Hot stage microscopy of contact melts of 5 with the less commonly used anionic nucleophiles azide and rhodanide illustrate the rapid formation of deeply colored products confirming the nucleophilic aromatic replacement of fluoride in the 4-fluorophenyl substituent. Remarkably, in addition to the conceived functional quarternizations, a neutral dimer chromophore (7) resulted from using

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Section: Synthetic Considerationsmentioning

confidence: 93%