Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.     

碘促进的苯并咪唑及其衍生物的合成

在碘的氧化作用下,由伯醇和邻苯二胺一步合成了苯并咪唑及其衍生物。考察了碘和碳酸钾用量及温度对反应产率的影响,反应较佳的条件为n(o-ClC6H4CH2OH)∶n(o-phenylenediamine)∶n(I2)∶n(K2CO3)=1.0∶1.1∶5.0∶5.0,反应温度70℃,反应时间5 h。用方法A在较佳的反应条件下2-(2-氯苯基)苯并咪唑的产率可达86%,用方法B其产率达69%。没有选择传统的醛或酸作为反应底物,而是选择了伯醇在碘的氧化作用下直接合成了目标产物,反应为合成苯并咪唑及其衍生物的一个新方法,探讨了可能的反应机理。     

<Emphasis Type="Italic">p</Emphasis>-(Dimethylamino)benzaldehyde modification of the Hantzsch reaction: Synthesis of 3-(1H-benzimidazol-2-yl)-5,7-dimethoxyquinolines

A three component cyclocondensation of p-(dimethylamino)benzaldehyde with 3,5-dimethoxyaniline and 2-phenacyl-1H-benzimidazoles gives previously unknown 2-aryl-3-(1H-benzimidazol-2-yl)-5,7-dimethoxyquinolines. The Hanztsch type reaction occurs in refluxing acetic acid and is accompanied by aromatization of the 1,4-dihydroquinolines formed through loss of N,N-dimethylaniline. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1792–1798, December, 2007.     

Benzimidazole condensed ring systems,III . Synthesis of some substituted 2,3-dihydrocyclopenta-1H-[4′,5′: 2,3]pyrido[1,2-a]benzimidazole-11-carbonitriles

Summary The synthesis of compound3 by condensing 1H-benzimidazole-2-acetonitrile (1) with ethyl cyclopentanone-2-carboxylate (2) in the presence of ammonium acetate is described. Methylation of3 with trimethyl phosphate yielded the N-methyl derivative4. Methods for converting3 to some of its related derivatives in which the carbonyl function was replaced by Cl, N₃ and amines are also reported.

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Kondensierte Ringsysteme des Benzimidazols, 3. Mitt.. Synthese von substituierten 2,3-Dihydrocyclopenta[4,5:2,3]pyrido[1,2-a]benzimidazol-11-carbonitrilen

Zusammenfassung Die Synthese der tetracyclischen Verbindung3 durch Kondensation von 1H-Benzimidazol-2-acetonitril (1) mit Cyclopentanon-2-carbonsäureester (2) in Gegenwart von Ammonacetat wird beschrieben. Die Methylierung von3 mit Trimethylphosphat liefert das N-Methylderivat4. Die Sauerstoffunktion in3 kann durch Chlor, Azid und Aminogruppen ersetzt werden.

     

高效液相色谱法测定鸡组织中苯并咪唑类药物残留标志物

建立了高效液相色谱同时测定鸡肉、鸡肝脏和鸡肾脏中11种苯并咪唑类药物残留标志物的方法。样品采用乙腈提取，经正己烷脱脂后以MCX固相萃取小柱净化，净化液浓缩处理后采用Atlantis T₃色谱柱分离，以甲醇-1%（v/v）乙酸水溶液为流动相进行梯度洗脱，紫外检测波长为292 nm，外标法定量检测。目标化合物在25~1000 μg/L范围内线性良好，定量限为50 μg/kg；在不同添加水平下目标化合物的回收率为70.91%~103.21%，相对标准偏差为1.48%~10.08%（n=6），精密度和准确度均符合要求，能够满足鸡组织中苯并咪唑类药物残留标志物的检测要求。     

Benzimidazole condensed ring systems,VI: Organic azides in heterocyclic synthesis,X: Synthesis of some substituted pyrimido[1,6-a]-benzimidazoles as potential antimicrobial agents

Summary The syntheses of 3-chloro derivatives of 2-alkyl-pyrimido[1,6-a]benzimidazol-1(2H)-ones2a, b as well as of 4,4-dichloro and 4,4-dibromo derivatives of 2-alkylpyrimido[1,6-a]benzimidazole-1,3(2H,4H)-diones3 a, b and4 are reported. Methods for converting some of the chloro compounds to azido (5, 6), amino (8), morpholino (9 a,10,11), piperidino (9 b), cyano (12), and methoxy (13) derivatives of the adopted tricyclic system are also described.

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Kondensierte Ringsysteme des Benzimidazols, 6. Mitt.: Organische Azide in der Heterocyclen-Synthese, 10. Mitt.: Synthese von substituierten Pyrimido[1,6-a]benzimidazolen als mögliche antimikrobielle Wirkstoffe

Zusammenfassung Die Synthese von 3-Chlor-2-alkyl-pyrimido[1,6-a]benzimidazol-1(2H)-onen (2 a, b) und von 4,4-Dichlor- und 4,4-dibrom-pyrimido[1,6-a]benzimidazol-1,3(2H,4H)-dionen (3 a, b, 4) wird beschrieben. Diese Verbindungen lassen sich zu den entsprechenden Azido- (5, 6), Amino- (8), Morpholino- (9 a, 10, 11), Piperidino- (9 b), Cyano- (12) und Methoxy- (13) Derivaten umwandeln.

     

Synthesis of 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-1,4-benzoxazines from oxides of internal perfluoroolefins

The reactions of oxides of internal trans-, cis-perfluoroolefins with o-phenylenediamine and 2-aminophenol in dioxane gave 2,3-bis(perfluoroalkyl)quinoxalines and 2,3-bis(perfluoroalkyl)-2H-1,4-benzoxazin-2-ols respectively in yields of 23-67%. When N,N-dimethylacetamide was used as a solvent an anionic isomerization of the oxides into ketones, which further yielded 2-(perfluoroalkyl)benzimidazoles in the case of o-phenylenediamine and 2-hydroxy-N-perfluoroalkanoylanilines in the case of 2-aminophenol, became the main path of these reactions. Unusual cyclization resulting in 2-pentafluoroethyl-2-pentafluoropropanoylbenzoxazolidine occurs on interaction between dodecafluoro-3,4-epoxyhexane and 2-aminophenol in N,N-dimethylacetamide.     

Selective Recyclization of 2-Aroylmethyl-1H-benzimidazole Hydrazones by Condensation with Dimethylformamide

2-Aroylmethyl-1H-benzimidazole hydrazones are converted to 1-[pyrazol-3(5)-yl]benzimidazoles by refluxing in dimethylformamide in the presence of trifluoroacetic acid. The same products are obtained by refluxing 2-aroylmethyl-1H-benzimidazoles with hydrazine hydrochloride in dimethylformamide. Electron donor substituents in the para position of the aryl fragment of the starting compounds do not favor the reaction.     

Reactions of 2-polyfluoroacylcyclohexanones with 1,2-diaminoarenes

Reactions of 2-polyfluoroacylcyclohexanones with 1,2-diaminoarenes yield, depending on the reaction conditions, various 2-polyfluoroalkyl-substituted benzimidazoles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 562–565, March, 1999.     

Quantum-chemical Analysis of the Recyclization Paths of 2-Phenacyl-1H-benzimidazole Phenylhydrazone

Quantum-chemical calculations of the recyclization of 2-phenacyl-1H-benzimidazole phenylhydrazone to a pyrazole compound agree with the experimental data. The transformation is impossible during heating and acid catalysis but does occur under the conditions of acylation. It takes place through the selective formation and spontaneous intramolecular rearrangement of the corresponding N-acylbenzimidazolium salt.