17334-09-7Relevant articles and documents
The Structure of +. and + Ions Formed from Vinylimidazoles, Studied by Collisionally Activated Dissociation Mass Spectrometry
Tilborg, M. W. E. M. van,Houte, J. J.,Thuijli, J. van
, p. 16 - 22 (1984)
Mass spectra of the three isomeric vinylimidazoles have been compared and the structures of the fragment ions +. and + have been investigated by collisionally activated dissociation mass spectrometry.The greater part of the non-decomposing ions m/z 68 from 2-vinylimidazole and from 2-imidazolecarboxylic acid methyl ester, and a minor part of this ion formed from the free acid, all have the same structure: the imidazole ring system, with hydrogens at both nitrogen atoms but none at C(2).An analogous structure, with an ethynyl group at C(2), is proposed for the m/z 93 ion from 2-vinylimidazole.
Diazafulvenones. Thermal Isomerizations and Eliminations in Alkoxycarbonyl and Anilinocarbonyl Derivatives of Imidazole
Maquestiau, A.,Tommasetti, A.,Pedregal-Freire, C.,Elguero, J.,Flammang, R.,et al.
, p. 306 - 309 (2007/10/02)
4-Carbonyl-4H-imidazole (10) and 2-carbonyl-2H-imidazole (11) are formed by flash vacuum pyrolysis of methyl 4- and 2-imidazolecarboxylates, respectively. 10 and 11 dimerize to diketopiperazines 14 and 16, respectively.The same products are also obtained from 4- and 2-(anilinocarbonyl)imidazoles, respectively.Methyl imidazole-1-carboxylate (4) on pyrolysis gives a ca. 1:1 mixture of the same ketenes 10 and 11, which dimerizes to a 1:2:1 ratio of diketopiperazines 14-16.In contrast, ethyl imidazole-1-carboxylate gave CO2, ethylene, and imidazole as the major products.The pyrolysis reactions were monitored by low-temperature infrared and high-temperature mass spectrometry.