- Thermal Rearrangement of 1,4-Dinitroimidazole to 2,4-Dinitroimidazole: Characterization and Investigation of the Mechanism by Mass Spectrometry and Isotope Labeling
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The thermal rearrangement of 1,4-dinitroimidazole to 2,4-dinitroimidazole has been investigated by differential scanning calorimetry and mass spectrometry techniques.When mixtures of independently prepared deuterium- and (15)N-labeled samples of the 1,4-isomer were subjected to thermal rearrangement, the resulting 2,4-dinitroimidazole failed to show isotope-scrambled molecular ions in its mass spectrum, suggesting that the reaction was intramolecular in nature.This was interpreted to mean that the mechanism was of the (1,5)-sigmatropic type rearrangement.Extensive NMR measurements were used to obtain unequivocal evidence for the identity of the assumed structures of the isomeric dinitroimidazoles.Two byproducts (4-nitroimidazole and a trinitroimidazole), formed during the rearrangement reaction, have also been identified.Plausible mechanisms for their formation are discussed.
- Bulusu, S.,Damavarapu, R.,Autera, J. R.,Behrens, R., Jr.,Minier, L. M.,et al.
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- Reactions of 1-Arenesulfonyl-4-nitroimidazoles with Aniline in Aqueous Methanol Solution
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Several 1-arenesulfonyl-4-nitroimidazoles were obtained and reacted with aniline in methanol-water medium at 65-70 deg C to yield mixtures of 1-arenesulfonylamide, 1-arenesulfonylanilide, 4-nitro-1-phenylimidazole and 4(5)-nitroimidazole in varied proportions depending on the arenesulfonyl group. - Key words: 1-arenesulfonyl-4-nitroimidazoles, nucleophilic substitution, imidazole ring transformation
- Suwinski, Jerzy,Salwinska, Ewa
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Read Online
- Preparation method of 4-nitroimidazole
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The invention discloses a preparation method of 4-nitroimidazole, which uses imidazole as a raw material and N-nitropyrazole (N-NP) and H2SO4 as nitrating agents to prepare the 4-nitroimidazole, and specifically comprises the following steps of putting 8 ml of 98% sulfuric acid into a four-neck bottle, adding 0.012 mol of imidazole into concentrated sulfuric acid at the temperature of 20 DEG C under the condition of mechanical stirring, heating in a water bath to 60 DEG C after the charging is completed, averagely dividing 0.024 mol of N-nitropyrazole into four parts to be sequentially added at the temperature, enabling the temperature rise phenomenon to occur in the reaction system in the charging process, conducting charging again after the temperature is reduced to the initial temperature, keeping stirring after charging is completed, conducting a constant-temperature reaction for 6 h at the temperature of 65 DEG C, pouring reaction liquid into a container containing ice blocks while the reaction liquid is hot, conducting stirring, reducing the temperature of the solution to 5 DEG C, and separating out white powder substances.
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Paragraph 0019-0027
(2021/07/09)
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- Synthesis, anti-HIV-1 and antiproliferative evaluation of novel 4-nitroimidazole derivatives combined with 5-hydroxy-4-pyridinone moiety
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In an effort to synthesize more effective non-nucleoside reverse transcriptase inhibitors (NNRTIs) against the HIV-1 infection, a new series of novel 4-nitroimidazole derivatives combined with 5-hydroxy-4-pyridinone moiety were designed by molecular docking studies, prepared and characterized by spectroscopic techniques. All the synthesized compounds were in vitro evaluated for their inhibitory effect against the HIV-1 replication in the MT-4 cells. Results showed that none of these synthesized compounds displayed any specific anti HIV-1 activity. Surprisingly, these compounds showed high cytotoxicity against MT-4 cells with low selectivity index (50 = 1.3 μM and EC50 = 1.8 μM respectively).
- Shirvani, Pouria,Fassihi, Afshin,Saghaie, Lotfollah,Van Belle, Siska,Debyser, Zeger,Christ, Frauke
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- Method for preparing 4, 5-dinitroimidazole by adopting microchannel reactor
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The invention discloses a method for preparing 4, 5-dinitroimidazole by adopting a microchannel reactor. According to the method, raw material mixing is enhanced by using a micromixer, and the mixinguniformity is limited by uneven flow fields generated by stirring in a prior reactor; a flow focusing technology adopted by the HPIMM micromixer can force two fluid thin layers to flow through a convergence chamber so as to generate efficient and uniform thin layer contact reaction, and the stoichiometric ratio of reactants is precisely controlled, so that the consumption of strong acid is reducedfrom the source, and the generation of multi-nitration byproducts caused by acid amount and temperature change during the reaction in a prior kettle reactor is eliminated, mass transfer resistance iseliminated, generation of hot spots is avoided, and the problem that the 4, 5-dinitroimidazole has great safety problems caused by intense heat release in the prior reactor is solved. According to the invention, a microsystem is utilized to carry out the synthesis of 4-nitroimidazole and 4, 5-dinitroimidazole, the yields can reach to 96.1% and 92.4%.
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Page/Page column 0042-0057; 0070-0072; 0076-0077
(2019/06/27)
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- Nitro-imidazoles in ferrocenyl alkylation reaction. Synthesis, enantiomeric resolution and in vitro and in vivo bioeffects
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Ferrocenylalkyl nitro-imidazoles (4a-h, 5a-h) were prepared via the regiospecific reaction of the α-(hydroxy)alkyl ferrocenes, FcCHR (OH) (1a–h; Fc = ferrocenyl; R = H, Me, Et, Pr, i-Pr, Ph, ortho-Cl-Ph, ortho-I-Ph), with nitro-imidazoles in aqueous organic medium (H2O-CH2Cl2) at room temperature in the presence of HBF4, within several minutes in good yields. X-ray structural data for racemic (R,S)-1-N-(benzyl ferrocenyl)-2-methyl-4-nitroimidazole (5f) were determined. The resulting enantiomers were resolved into enantiomers by analytical HPLC on modified amylose or cellulose chiral stationary phases. The viabilities of 4b, 4d, 5b, 5c in vitro, and in experiments in vivo antitumor effects of 1-N-ferrocenylethyl-4-nitroimidazole (4b) against murine solid tumor system Ca755 carcinoma were evaluated.
- Snegur, Lubov V.,Lyapunova, Maria V.,Verina, Daria D.,Kachala, Vadim V.,Korlyukov, Alexander A.,Ilyin, Mikhail M.,Davankov, Vadim A.,Ostrovskaya, Larissa A.,Bluchterova, Natalia V.,Fomina, Margarita M.,Malkov, Victor S.,Nevskaya, Kseniya V.,Pershina, Alexandra G.,Simenel, Alexander A.
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- Determination of inter-ionic and intra-ionic interactions in a monofluorinated imidazolium ionic liquid by a combination of X-ray crystallography and NOE NMR spectroscopy
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We report the very first application of a Transient 1D 1H{19F} NOE NMR experiment in neat ionic liquids. In comparison with classical 2D HOESY NMR spectroscopy, a substantial reduction in measurement time is gained with comparable quality and information content of the spectra. In combination with classical X-ray crystallography, we have applied this technique for the determination of inter-ionic distances (i.e. probabilities of presence) utilizing an ionic liquid containing a monofluorinated imidazolium cation. Copyright
- Lingscheid, Yves,Paul, Mathias,Br?hl, Andreas,Neud?rfl, J?rg-Martin,Giernoth, Ralf
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- The effect of an electron-withdrawing group in the imidazolium cation: The case of nitro-functionalized imidazolium salts as acidic catalysts for the acetylation of glycerol
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The acetylation of glycerol was achieved with high conversion and selectivity towards triacetin at low temperatures and short reaction times by using acidic imidazolium salts as catalysts. Moreover, the addition of a nitro group to the imidazolium cation affords a much more competent catalyst, indicating a significant effect provided by the simple electronic change in the imidazolium cation. Theoretical calculations revealed increased polarization of the acidic hydrogen bond on the nitrated salts, which may be related to their superior catalytic behavior when compared to the non-functionalized salts. Combining the preliminary experimental and theoretical results, it is possible to suppose that the catalytic activity of acidic imidazolium salts may be better comprehended by its Br?nsted acidities, but other parameters such as hardness, electronegativity, electrophilicity and ion-pair binding energy were also evaluated in order to investigate their effects in the acetylation of glycerol promoted by these acidic imidazolium salts.
- Morais, Eduardo M.,Grillo, Igor B.,Stassen, Hubert K.,Seferin, Marcus,Scholten, Jackson D.
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p. 10774 - 10783
(2018/07/05)
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- Highly efficient protocol for the aromatic compounds nitration catalyzed by magnetically recyclable core/shell nanocomposite
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An efficient protocol for the nitration of aromatic compounds in the presence of a catalytic amount of sulfuric acid-functionalized silica-based magnetic core/shell nanocomposite was reported. The designed products were obtained in high yields in relatively short reaction times at room temperature under solvent-free conditions. The nanocatalyst was simply recovered from the reaction mixture by using an external magnet and efficiently reused for several times. The characterization of particle size, morphology and elemental analysis of the nanocatalyst were provided by scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy analyses, respectively.
- Maleki, Ali,Aghaei, Morteza,Paydar, Reza
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p. 485 - 490
(2017/01/10)
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- 1,3-diaminoguanidine-2,4,5-trinitroimidazole salt and preparation method thereof
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The invention discloses a 1,3-diaminoguanidine-2,4,5-trinitroimidazole salt and a preparation method thereof, belongs to the technical field of organic energetic materials and aims at solving the problem in the prior art that a TNT-based melt-cast explosive harms the environment in the use process. The method comprises the steps of using imidazole as a reaction raw material to generate 2,4,5-trinitroimidazole through step-by-step nitrification; enabling a nitrification product to react with a potassium carbonate/potassium chloride solution to form a salt to prepare 2,4,5-trinitroimidazole potassium salt; and finally obtaining a target product 1,3-diaminoguanidine-2,4,5-trinitroimidazole salt through double-decomposition reaction of 1,3-diamino guanidine hydrochloride and the 2,4,5-trinitroimidazole potassium salt. The preparation method is simple, low in preparation cost and good in security; and the final product 1,3-diaminoguanidine-2,4,5-trinitroimidazole salt is high in purity.
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Paragraph 0019
(2017/07/20)
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- Synthesis method for generating 4-nitroimidazole by oxidizing 4-aminooimidazole
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The invention discloses a synthesis method for generating 4-nitroimidazole by oxidizing 4-aminooimidazole. The method comprises the following steps specifically: S1, oxidation: 4-aminooimidazole is added to a flask and mixed with water and peroxymonosulfate, and the mixture is stirred to react at the temperature of 30-60 DEG C for 12-24 h; S2, extraction: dichloromethane is used for extraction after the reaction ends, and a dichloromethane layer is taken; S3, distillation for solvent removal: an extracting solution is cooled and distilled under reduced pressure, so that dichloromethane is removed, and 4-nitroimidazole is obtained. 4-aminooimidazole is taken as a raw material for one-step direct oxidation generation of 4-nitroimidazole, the production procedure is simplified, and the procedure cost is reduced; peroxymonosulfate is taken as a nitration reagent, concentrated sulfuric acid and sodium nitrite are not required as nitration reagents, reaction conditions are mild, water is taken as a reaction solvent, the safety coefficient is high, and the yield of 4-nitroimidazole reaches 90%.
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Paragraph 0034; 0035
(2017/01/02)
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- High-energy-density materials based on 1-nitramino-2,4-dinitroimidazole
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New energetic salts based on 1-nitramino-2,4-dinitroimidazole were successfully synthesized. The salts were fully characterized by 1H, 13C NMR and IR spectroscopy, differential scanning calorimetry (DSC), and elemental analyses. The salts were found to have good physical and detonation properties. The structure of guanidinium salt (3) was further confirmed by single-crystal X-ray diffraction. The densities of the energetic salts ranged between 1.70 and 1.93 g cm-3 as measured by a gas pycnometer. The detonation pressures and velocities calculated by the EXPLO5 code ranged within 29.3-40.5 GPa and 8370-9209 m s-1, respectively. The Royal Society of Chemistry 2013.
- Song, Jinhong,Wang, Kai,Liang, Lixuan,Bian, Chengming,Zhou, Zhiming
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p. 10859 - 10866
(2013/09/02)
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- Synthesis, crystal structure and antibacterial activity of new highly functionalized ionic compounds based on the imidazole nucleus
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Several new highly functionalized imidazolium derivatives were synthesized, via appropriate synthetic routes, using imidazole, 1-methylimidazole and 2-phenyl-1-methylimidazole as key intermediates. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella thipymurium using disk-diffusion and MIC methods. Crystal X-ray structures are reported for six compounds.
- Bahnous, Mebarek,Bouraiou, Abdelmalek,Chelghoum, Meryem,Bouacida, Sofiane,Roisnel, Thierry,Smati, Farida,Bentchouala, Chafia,Gros, Philippe C.,Belfaitah, Ali
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p. 1274 - 1278
(2013/03/14)
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- Compounds containing 2-substituted imidazole ring for treatment against human African trypanosomiasis
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A series of compounds containing 2-substituted imidazoles has been synthesized from imidazole and tested for its biological activity against human African trypanosomiasis (HAT). The 2-substituted 5-nitroimidazoles such as fexinidazole (7a) and 1-[4-(1-methyl-5-nitro-1H-imidazol-2-ylmethoxy)-pyridin-2- yl-piperazine (9e) exhibited potent activity against T. brucei in vitro with low cytotoxicity and good solubility. The presence of the NO2 group at the 5-position of the imidazole ring in 2-substituted imidazoles is the crucial factor to inhibit T. brucei.
- Samant, Bhupesh S.,Sukhthankar, Mugdha G.
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supporting information; experimental part
p. 1015 - 1018
(2011/03/21)
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- METHODS FOR THE PRODUCTION OF 2-HALO-4-NITROIMIDAZOLE AND INTERMEDIATES THEREOF
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The present invention relates to a method for the production of 2-halo-4-nitroimidazole and intermediates thereof. Further, the present invention relates to a production process of 1,4-dinitroimidazole comprising subjecting 4-nitroimidazole to nitration reaction. Furthermore, the present invention relates to a production process of 4-nitroimidazole comprising subjecting imidazole to nitration reaction.
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Page/Page column 75-76
(2010/04/03)
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- Synthesis of 2,3-dihydro-7-nitroimidazo[5,1-b]oxazoles as potential tuberculostatic agents
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A series of 2,3-dihydro-7-nitroimidazo[5,1-b]oxazoles has been prepared in one-pot reaction. The proposed new method of their synthesis requires a treatment of 4,5-dinitroimidazole or 2-methyl-4,5-dinitroimidazole with oxiranes. Some of the obtained compounds have been tested in vitro for antimycobacterial activity and the spatial structure of them has been also discussed.
- Zwawiak, Justyna,Olender, Dorota,Zwolska, Zofia,Augustynowicz-Kopec, Ewa,Zaprutko, Lucjusz
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scheme or table
p. 229 - 233
(2009/04/04)
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- N-vinyl-nitroimidazole cycloadditions: Potential routes to nucleoside analogues
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Cycloaddition reactions of 4-nitro- and 5-nitro-1-vinylimidazoles have been investigated. The cycloadducts obtained are potential intermediates for synthesis of purine nucleoside analogues via reduction to the corresponding aminoimidazoles. A byproduct obtained using benzonitrile oxide as 1,3-dipolarophile has been identified as a novel tricyclic isomer 12 of the cycloadduct 11. Georg Thieme Verlag Stuttgart.
- Clayton, Russell,Ramsden, Christopher A.
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p. 2695 - 2700
(2007/10/03)
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- Biosynthesis of the thiamin pyrimidine: The reconstitution of a remarkable rearrangement reaction
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The conversion of 5-aminoimidazole ribonucleotide (AIR) into 4-amino-2-methyl-5-hydroxymethylpyrimidine (HMP) is a fascinating reaction on the thiamin biosynthetic pathway in bacteria and is probably the most complex unresolved rearrangement in primary metabolism. We have successfully reconstituted this reaction in a cell-free system. The E. coli thiC gene product and an additional unidentified E. coli protein are required for the reaction. In addition, SAM and nicotinamide cofactors are required for full activity. Labeling studies to determine the origin of most of the atoms in the pyrimidine are described. Based on these studies, a new mechanism for HMP formation is proposed.
- Lawhorn, Brian G.,Mehl, Ryan A.,Begley, Tadhg P.
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p. 2538 - 2546
(2007/10/03)
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- Design and synthesis of heterocyclic hydroxamic acid derivatives as inhibitors of Helicobacter pylori urease
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Helicobacter pylori produces ammonia to help counter the acidic environment in the human stomach. The production of ammonia, essential for the microorganism's survival and virulence, is the product of enzymatic conversion of urea by the H. pylori's urease. Inhibition of urease activity by dipeptide hydroxamic acids has previously been demonstrated using a variety of fluorides, thiols and hydroxamic acids. Studies employing computer-aided drug design techniques have been utilized to suggest a novel series of heterocyclic hydroxamic acid derivatives as potential as urease inhibitors. The heterocyclic compounds 7a,b, 10b, 12b, 16b, and 19b have been designed, synthesized, and preliminarily tested as dipeptide mimics which offer a structure that is more biologically stable than that of the reported dipeptide inhibitors.
- Muri, Estela Maris F.,Mishra, Hetal,Avery, Mitchell A.,Williamson, John S.
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p. 1977 - 1995
(2007/10/03)
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- Synthesis and Characterization of 1-methyl-2,4,5-trinitroimidazole (MTNI)
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We have reinvestigated the synthesis of 1-methyl-2,4,5-trinitroimidazole (MTNI; 1), and further characterized its physical properties. It is a promising candidate as an insensitive high explosive. Compound 1 was synthesized from the imidazole (2), via a 5-step sequence of reactions, and subjected to various sensitivity tests for explosives. The structure of 1 was characterized by X-ray diffraction. The crystal is orthorhombic; C4H3N5O6, M = 217.11, Z = 8, Pca21, a = 8.6183(6) Angstroem, b = 17.7119(12) Angstroem, c = 10.6873(7) Angstroem, V = 1631.38(19) Angstroem3, Dc = 1.768 g/cm3. The structure was refined to R = 0.0284 for 3201 independent reflections with I > 2?(I). The molecular structures calculated by high levels of ab initio and density functional theories were in good agreement with those observed by X-ray experiment. According to our preliminary sensitivity tests, 1 was characterized to be intermediate in sensitivity between RDX and TNT. The explosive performances were evaluated theoretically, and were found to be comparable to those of RDX. In addition, owing to its low melting point (82 deg C), 1 is believed to be an excellent candidate for inclusion in melt-castable explosives, and may lead to increased explosive power.
- Cho, Jin Rai,Kim, Kwang Joo,Cho, Soo Gyeong,Kim, Jeong Kook
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p. 141 - 148
(2007/10/03)
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- Ozone-mediated Nitration of Pyrazole, Imidazole and Uracil with Nitrogen Dioxide
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In the presence of ozone, pyrazole and uracil were easily N-nitrated with nitrogen dioxide in dichloromethane at 0°C to give the corresponding 1-nitro derivatives, whilst imidazole was C-nitrated in the additional presence of methanesulfonic acid as catalyst to afford the 4-nitro derivative, each product being obtained in a satisfactory yield.
- Suzuki, Hitomi,Nonoyama, Nobuaki
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p. 244 - 245
(2007/10/03)
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- Reactions of 1,4-dinitroimidazoles with hydrazines
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Reaction of 2-methyl-1,4-dinitroimidazole with hydrazine results in expansion of the imidazole ring and formation of the 1.2.4-triazine derivative. Reaction of 1,4-dinitroimidazole with N-aminomorpholine yields 1-(N-morpholino)-4-nitroimidazole, by degenerative transformation of the imidazole ring. Treatment of 1,4-dinitroimidazoles with t-butoxycarbonylhydrazine results in the break down of the imidazole ring and formation of glyoxal dihydrazone derivatives. Structures of representative heterocyclic products were determined by X-ray analysis.
- Suwinski, Jerzy,Szczepankiewicz, Wojciech,Holt, Elizabeth M.
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p. 14905 - 14916
(2007/10/03)
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- RING TRANSFORMATION REACTIONS IN 4-NITROIMIDAZOLES FOLLOWING AN ATTACK OF NUCLEOPHILES
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It was proved that 4-nitroimidazoles substituted at the nitrogen atom 1 with electron acceptor groups (aryl, arenesulfonyl, nitro) in reactions with some nucleophiles yield the products of ordinary or degenerated imidazole ring transformation (oxadiazoles, triazoles, imidazoles).
- Suwinski, Jerzy,Pawlus, Wojciech,Salwinska, Ewa,Swierczek, Krzysztof
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p. 1511 - 1520
(2007/10/02)
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- NITROIMIDAZOLES. PART XIII. HYDROLYSIS OF 1,4-DINITROIMIDAZOLES IN WATER SOLUTIONS OF SULFURIC ACID
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The kinetics of the hydrolysis of 1,4-dinitroimidazole in aqueous solutions of sulfuric acid of four concentrations from 9 to 40percent, at 25 deg C, has been investigated using UV-VIS spectrophotometric method.The mechanism of the reaction has been proposed.
- Llempen, H.,Suwinski, J.
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p. 819 - 826
(2007/10/02)
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- SYNTHESIS AND AMINATION OF 2,4-DICHLORO-5-FLUOROPYRIMIDINE
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2,4-Dichloro-5-fluoropyrimidine was prepared by the chlorination of 5-fluorouracil with phosphorus pentachloride in absence of solvent.The reaction of 2,4-dichloro-5-pyrimidine with primary and secondary aliphatic and heteroaromatic amines in an aqueous medium yields 2-chloro-4-RR'-amino-5-fluoropyrimidines, with stereoselective substitution of chlorine in the C4 position.The substances obtained have well-defined fungicidal activity.
- Kovalenko, A. L.,Krutikov, V. I.,Zolotukhina, M. M.,Alekseeva, L. E.
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p. 1122 - 1125
(2007/10/02)
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- REACTIONS OF 4,5-DINITROIMIDAZOLE AND 4(5)-NITROIMIDAZOLE-5(4)-SULFONIC ACID WITH NUCLEOPHILES
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The reactions of 4,5-dinitroimidazole and 5(4)-nitroimidazole-4(5)-sulfonic acid with nucleophilic agents were studied.Mercapto-, alkoxy-, and aminonitroimidazoles were synthesized.In the reaction of dinitroimidazole with sodium alkoxides 5(4)-nitroimidazole was obtained in addition to alkoxynitroimidazoles.It is shown that in the formation of salts of the starting imidazoles with bases nucleophilic-substitution reactions take place only with "soft" reagents.
- Mokrushin, V. S.,Belyaev, N. A.,Kolobov, M. Yu.,Fedotov, A. N.
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p. 650 - 652
(2007/10/02)
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