CIX.—Bromo-derivatives of glyoxaline

Balaban, Isidore Elkanah; Pyman, Frank Lee

doi:10.1039/ct9222100947

Cited by 51 publications

(16 citation statements)

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“…The starting material 5(4)-bromo-4(5)-nitroimidazole 1 was prepared according to the literature method [14]. The reaction of 1 with diazomethane in dry diethyl ether afforded 1-methyl-5-bromo-4-nitro-1H-imidazole 3 as major product.…”

Section: Chemistrymentioning

confidence: 99%

Synthesis and In‐Vitro Antibacterial Activity of 5‐Substituted 1‐Methyl‐4‐nitro‐1H‐imidazoles

Letafat

Emami

Aliabadi

et al. 2008

Archiv der Pharmazie

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A series of 5-substituted 1-methyl-4-nitro-1H-imidazole derivatives were synthesized and evaluated for in-vitro antibacterial activity against a panel of microorganisms including Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, and Helicobacter pylori using conventional agar dilution method. Among the test compounds, 1-methyl-4-nitro-5-(phenylsulfonyl)-1H-imidazole was the most potent against Gram-positive bacteria, with a MIC value of < or =8 microg/mL. All compounds showed no significant activity against Gram-negative bacteria at concentrations < or =64 microg/mL. The MIC values against 15 clinical isolates of H. pylori indicated that compounds 10 and 11 were the most active compounds in this series in terms of inhibiting the growth of H. pylori (MIC = 2 microg/mL). It was also demonstrated that their corresponding activities were four times larger than that of metronidazole.

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Section: Chemistrymentioning

confidence: 99%

Synthesis and In‐Vitro Antibacterial Activity of 5‐Substituted 1‐Methyl‐4‐nitro‐1H‐imidazoles

Letafat

Emami

Aliabadi

et al. 2008

Archiv der Pharmazie

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“…Imidazoles lacking a 2-NH, group, however, give substitution products upon bromination (see above and refs. 16,25,26), suggesting that the external amino substituent in 17 may play a direct role. N-Bromination, for example, results in an N-bromoimidazole 22, where loss of bromide would lead to the cation 23 and hence to 18.…”

Section: No2mentioning

confidence: 99%

Preparation and reactions of bromo-2-nitro- and bromo-2-aminoimidazoles

Farah¹,

McClelland²

1993

Can. J. Chem.

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Can. J. Chem. 71,427 (1993). Treatment of 1-methyl-2-nitroimidazole with bromine in water resulted in rapid dibromination to give 4,5-dibromo-1-methyl-2-nitroimidazole. In dioxane, the bromination was slower, and could be controlled to give 4-bromo-1-methyl-2-nitroimidazole 5 and 5-bromo-1-methyl-2-nitroimidazole 6 in a 4 : 1 ratio. In an attempt to displace the bromine, the monobromo compounds were treated with cysteamine hydrochloride. In each case the nitro group was displaced instead, the 4-bromo 5 resulting in 2-[(2-aminoethyl)thio]-4-bromo-1-methylimidazole 9 as sole product, and the 5-bromo 6 giving two products identified as the monosubstituted 2-[(2-aminoethyl)thio]-5-bromo-1-methylimidazole 13 and the disubstituted 2,5-bis[2-(aminoethyl)thio]-1-methylimidazole 12. The latter product forms by further reaction of the former and was the sole material observed at long reaction times. A fraction of 12 may also originate from an initial displacement of bromine giving 5-[(2-aminoethy1)thiol-1-methyl-2-nitroimidazole 14, although this cannot be observed due to a rapid further displacement of its nitro group. The bromonitroimidazoles 5 and 6 were reduced to 4-bromo-2-amino-1-methylimidazole 25 and 5-bromo-2-amino-1-methylimidazole 26 with Zn/HCl. On reflux in water, in the presence or absence of cysteamine hydrochloride, these undergo a protodebromination resulting in the same product, 2-amino-1-methylimidazole 17. In D20 the 4-bromo isomer was demonstrated to react specifically to give 2-amino-4-deuterio-1-methylimidazole 27. Attempted preparation of the bromoaminoimidazoles 25 and 26 by bromination of 2-amino-1-methylimidazole in water resulted in the clean formation of cis and trarzs 2-amino-4,5-dihydro-4,5-dihydroxyimidazolium ions 18. SALIM F. FARAH et ROBERT A. MCCLELLAND. Can. J. Chem. 71, 427 (1993) Le traitement du 1-methyl-2-nitroimidazole avec du brome dans l'eau conduit a une dibromation rapide, avec formation du 4,5-dibromo-1-methyl-2-nitroimidazole. Dans le dioxane, la bromation est plus lente et elle peut &tre contr6lCe pour conduire a la formation des 4-bromo-(5) et 5-bromo-(6) 1-methyl-2-nitroimidazoles, dans un rapport de 4 : 1. Dans un effort pour deplacer le brome, on a trait6 les composCs monobromes avec de chlorhydrate de la cystkinamine. Dans chaque cas, c'est plut6t le groupe nitro qui a Ct C deplace; le derive 4-brome (5) conduit uniquement au 2-[(2-aminoCthy1)thiol-4-bromo-1-methylimidazole (9) alors que le compose 5-bromC (6) fournit deux produits identifies comme le 2-[(2-aminotthy1)thiol-5-bromo-1-methylimidazole (13) monosubstituC et le 2,5-bis-[2-(aminoCthy1)thiol-1-methylimidazole (12) disubstitue. Ce dernier compose se forme par reaction ulterieure du premier; il est le seul produit a se former aprits des temps de reactions prolonges. Une partie du compose 12 peut aussi provenir d'un deplacement initial du brome conduisant au 5-[(2-aminoethyl)thio]-1-methyl-2-imidazole (14); toutefois, on ne peut pas observer sa formation a cause de la substitution rapide du groupe nitro. On...

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“…Bromination of imidazole, first described in 1877 [1], gives 2,4,5-tribromoimidazole [2,3]; the fully brominated derivative is also obtained from 1-methylimidazole [4,5]. Different brominating agents and systems are known to effect this transformation [6 -9].…”

Section: Introductionmentioning

confidence: 99%

“…Different brominating agents and systems are known to effect this transformation [6 -9]. Dibromo and monobromo compounds have been obtained by selective reduction of tribromo compounds using sodium sulfite [2,3] or butyllithium [3]. Removal of the most reactive bromine atom in position 2 by a Grignard reagent gave 4,5-dibromo-1-methylimidazole in good yield [5].…”

Section: Introductionmentioning

confidence: 99%

Bromination of 1-Hydroxyimidazoles. Synthesis and Crystal Structures

Laus

Wurs

Kahlenberg

et al. 2012

Zeitschrift Für Naturforschung B

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Bromination of 1-hydroxyimidazole 3-oxide and 1-hydroxy-2-methylimidazole 3-oxide using bromine in acetic acid gave 2-bromo-1,3-dihydroxyimidazole hydrobromide and 4,5-dibromo-1,3-dihydroxy-2-methylimidazole hydrobromide, respectively. In contrast, bromination in aqueous mixture (acetic acid, methanol, dimethylformamide, tetrahydrofuran) yielded 2,4,5-tribromo-1-hydroxyimidazole. Crystal structures of four compounds were determined by X-ray diffraction.

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CIX.—Bromo-derivatives of glyoxaline

Cited by 51 publications

References 0 publications

Synthesis and In‐Vitro Antibacterial Activity of 5‐Substituted 1‐Methyl‐4‐nitro‐1H‐imidazoles

Synthesis and In‐Vitro Antibacterial Activity of 5‐Substituted 1‐Methyl‐4‐nitro‐1H‐imidazoles

Preparation and reactions of bromo-2-nitro- and bromo-2-aminoimidazoles

Bromination of 1-Hydroxyimidazoles. Synthesis and Crystal Structures

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