Parallel Solid-Phase Synthesis of disubstituted 3-(1H-benzo[d]imidazol-2-yl)imidazolidine-2,4-diones and 3-(1H-benzo[d]imidazol-2-yl)-2-thioxoimidazolidin-4-ones

A multistep approach to construct novel 3-(1H-benzo[d]imidazol-2-yl)imidazolidine-2,4-diones and 3-(1H-benzo[d]imidazol-2-yl)-2-thioxoimidazolidin-4-ones from commercially available amino acids, amines, and carboxylic acids is described. Coupling of Fmoc-amino acid to resin-bound aminobenzimidazole provided following Fmoc elimination free amine. Treatment of the free amine with 1,1′-carbonyldiimidazole or 1,1′-thiocarbonyldiimidazole furnished the corresponding hydantoins and thiohydantoins via intramolecular cyclization. The desired aminobenzimidazole tethered hydantoins or thiohydantoins were isolated in good yields.     

Self-Catalyzed One-Pot Four-Component Green Synthesis of 2-Amino-6-[1,4-dioxo-3,4-dihydrophthalazin-2(1H)-yl]-4-phenyl-4H-pyran-3,5-dicarbonitriles

Russian Journal of Organic Chemistry - The title compounds were synthesized in good yields by one-pot four-component condensation of phthaloyl dichloride, ethyl cyanoacetohydrazide, malononitrile,...     

Synthesis,Crystal Structure and Luminescent Property of a Dinuclear Cadmium Complex Based on 2-(2-(1H-Benzo[d]imidazol-2-yl)-phenyl)-1-phenyl-1H-benzo[d]imidazole

A dinuclear cadmium complex [Cd_2(bppb)Cl_4×2DMF](1), where bppb is 2-(2-(1 Hbenzo[d]imidazol-2-yl)phenyl)-1-phenyl-~1 H-benzo[d]imidazole, was synthesized and characterized by X-ray single-crystal structure analyses. For 1: C_(58) H_(50) Cd_2 Cl_4 N_(10) O_2, M_r = 1285.68, monoclinic system, space group P2_1/n, a = 16.136(3), b = 10.612(2), c = 16.270(3) ?, β = 96.209(2)°, V = 2769.7(9) ?~3, Z = 2, D_c = 1.542 g/cm~3, λ = 0.71073 ?, μ(Mo Kα) = 1.013 mm~(–1), F(000) = 1296, S = 1.055, R = 0.0393 and wR = 0.1185 for 4876 observed reflections with I 2σ(I). One 9 mium ion which is five-coordinated by three chloride ions and two nitrogen atoms from bppb. Two cadmium ions are bridged by two chloride ions. The Cd_2(bppb)_2 Cl_2(μ-Cl_2) decomposes at 350 ℃ which is much lower by 70 ℃ than [Cd_2(bpbb)_2 Cl_2(μ-Cl_2)](420 ℃). The complex emits blue luminescence in both DMF solution and solid powder. Phenyl ring substituting NH hydrogen atom of benzimidazole group in ligand can not obviously change the UV-vis and luminescence spectra peaks location of the benzimidazole cadmium complex.     

Different synthetic routes to 4-(1H-benzo[d]imidazol-2-yl)aniline

The benzimidazole nucleus is an important pharmacophore in drug discovery, being a good bioisostere of naturally occurring nucleotides. This heterocycle may represent a type of privileged substructure which can interact with proteins and enzymes; it has, hence, been extensively utilized as a drug scaffold in medicinal chemistry. The connection between wide ranging biological activity and compounds containing the benzimidazole nucleus is known, and well documented in the literature. Benzimidazole derivatives have a multitude of interesting pharmacological activity, including antiviral, antitumor, antihypertensive, proton pump inhibitory, anthelmintic, antimicrobial, and anti-inflammatory activity. Accordingly, a brief survey is given below covering the synthesis of 2-phenybenzimidazole derivatives and their biological importance.     

Erratum to: Synthesis and Antimicrobial Activity of Novel N3,N5-Bis[1-({1-[2-((E)-benzylidene)hydrazinyl]-1-oxo-3-phenylpropan-2-yl}amino)-3-methyl-1-oxobutan-2-yl]pyridine-3,5-dicarboxamides

Russian Journal of General Chemistry - Erratum     

1-芳甲酰基-3-[4-((2-氰基亚胺基-1,3-噻唑烷-3-基)甲基)-噻唑-2-基]硫脲的合成及其生物活性研究

为了寻找高活性的杂环农药,将酰基硫脲骨架引入到噻唑分子结构中,设计合成了14个未见文献报道的1-取代苯甲酰基-3-[4-((2-氰基亚胺基-1,3-噻唑烷-3-基)甲基)-噻唑-2-基]硫脲类化合物.采用核磁共振氢谱和元素分析确认了新化合物的结构.初步的生物活性测试结果表明,部分标题化合物显示出一定的杀菌、植物生长调节或除草活性.     

Pd(II)-Catalyzed Benzimidazole-Assisted Annulation of 3-(1H-Benzo[d]imidazol-2-yl)-2H-chromen-2-one: Access to Imidazo[1,2-a]chromeno[3,4-c]pyridine

Palladium-catalyzed [4+2] oxidative annulation of coumarin-benzimidazoles with olefins for the synthesis of polycyclic aromatic hydrocarbons have been achieved. This synthetic protocol gives access to a wide range of structurally distinct imidazo[1,2-a]chromeno[3,4-c]pyridines in moderate to good yield with wide functional group tolerance. Further, photophysical properties of annulated scaffolds have been examined, which discloses their interesting solvatochromic emission behaviors.     

Synthesis and Some Properties of 2-(5-Methyl-2-Phenyl-2H-1,2,3-Diazaphosphol-4-yl)-4H-Benzo[d]-1,3,2-Dioxaphosphorin-4-One

Abstract

2-(5-Methyl-2-phenyl-2Н-1,2,3-diazaphosphol-4-yl)-4H-benzo[d]-1,3,2-dioxaphosphorin-4-one 1 readily reacts with hexafluoroacetone, mesoxalic acid diethyl ester, trifluoropyruvic acid ethyl ester and chloral to give 2-(5-methyl-2-phenyl-2H-1,2,3-dizaphosphole-4-yl)-derivatives of 1,3,2- and 1,4,2-dioxaphosphepines.     

Synthesis and Antimicrobial Activity of 2-Substituted-3-((3-(6-Nitrobenzo[D]thiazol-2-yl)-4-oxo-3,4-Dihydroquinazolin-2-yl)Methyl)-1,3,4-thiadiazol-3-ium-5-thiolate

Abstract

A new series of 2-substituted-3-((3-(6-nitrobenzo[d]thiazol-2-yl)-4-oxo-3,4-dihydroquinazolin-2-yl)methyl)-1,3,4-thiadiazol-3-ium-5-thiolate 6(a–j) was synthesized starting from anthranilic acid 1. The structures of the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, mass spectra, and elemental analysis. The final compounds were tested for their antimicrobial activity against several microbes.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and tables.]     

Synthesis,characterization and anticancer evaluation of 2-(naphthalen-1-ylmethyl/naphthalen-2-yloxymethyl)-1-[5-(substituted phenyl)-[1,3,4]oxadiazol-2-ylmethyl]-1H-benzimidazole

In the present study o-phenylenediamine and naphtene-1-acetic acid/2-naphthoxyacetic acid were used as a starting material through a series of steps and 2-(naphthalen-1-ylmethyl/Naphthalen-2-yloxymethyl)-1H-benzimidazol-1-yl]acetohydrazide 5a, 5b were obtained. In the first series 1,3,4-oxadiazole derivatives have been synthesized from Schiff base of the corresponding hydrazide i.e. 2-[2-(naphthalen-1-ylmethyl)-1H-benzimidazol-1-yl]acetohydrazide 5a by using Chloramin-T. In the second series 1,3,4-oxadiazole has been synthesized from 2-{2-[(naphthalen-2-yloxy)methyl]-1Hbenzimidazol-1-yl}acetohydrazide 5b by using phosphorous oxychloride and aromatic acid. These compounds were evaluated by IR, NMR, Mass spectrometry, elemental analysis and finally in vitro anticancer evaluation was carried out by NCI 60 Cell screen at a single high dose (10–5 M) on various panel/cell lines. One compound 7c was found to be the most active on breast cancer cell line and compounds 4b and 7d were moderately active.     

A fluorescent probe for both pH and Zn2+ based on 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenol

A sensitive fluorescent probe 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenol (HBIZ) for pH and Zn2+ has been developed. Great changes have taken place in the UV-vis absorption and fluorescence spectra for HBIZ upon increasing pH of its aqueous solution, acting as a pH-induced emission "off-on-off" switch with large enhancement factors of ～290 and ～75 over the pH range of 1.00-5.40 and 5.20-10.40. A over 100-fold fluorescence enhancement was also observed after complexation of HBIZ to Zn2+ in N,N-dimethylformamide.     

Synthesis of 6-Amino-5-R2-7-(6-R1-4-oxo-3,4-dihydro-2-quinazolyl)-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles

It has been found that malonodinitrile and 2-(6-R¹-oxo-3,4-dihydro-2-quinazolyl)acetonitrile in the presence of triethylamine undergo hetarylation by 5,6-dichloro-2,3-pyrazinedicarbonitrile at the active methylene group to give the triethylammonium salt of 2-(3-chloro-5,6-dicyano-2-pyrazinyl)malononitrile or 5-chloro-6-cyano(6-R¹-4-oxo-1,2,3,4-tetrahydro-2-quinazolylidene)methyl-2,3-pyrazinedicarbonitriles. Reaction of these with primary amines leads to annelation of the pyrrole ring at the pyrazine [b] edge to give 6-amino-5-R-5H-pyrrolo[2,3-b]pyrazine-2,3,7-tricarbonitriles and 6-amino-5-R²-7-(6-R¹-4-oxo-3,4-dihydro-2-quinazolyl)-5H-pyrrolo[2,3-b]pyrazine-2,3-dicarbonitriles respectively.     

Ring closure of 1-[4-(imidazol-1-yl)phenyl]-3-phenyl-2-propen-1-one derivatives to potential biologically active compounds

1-[4-(Imidazol-1-yl)phenyl]-3-phenyl-2-propen-1-one 1 reacted with acetone cyanohydrin, ethyl phenylacetate and cyanoacetamide to give the adducts 2, 8 and 10 respectively. Action of hydrazine hydrate on both the γ-ketonitrile 2 and the corresponding γ-ketoacid 4 led to pyridazine derivatives 3 and 5 . 4,5-Dihydropyridazinone 5 was dehydrogenated by the action of bromine in acetic acid to give pyridazinone 6 . Cyclization of acid 8 in acetic medium resulted in α-pyrone 9 . Cyanopentanamide 10 was converted with hydrochloric acid into δ-ketoacid 13 which led to α-pyrone 14 via an intramolecular dehydration. Refluxing 10 in the presence of acetic acid and ammonium acetate gave 3,4-dihydropyridone 11 which was dehydrogenated to produce pyridone 12 .     

N-hetaryl-2-cyanoacetamides in the synthesis of substituted (E)-N-hetaryl-2-cyanoacrylamides, (E)-N-alkyl-N-hetaryl-2-cyanoacrylamides, and 6-amino-2-oxo-4-phenyl-1-(pyridin-2-yl)-1,2-dihydropyridine-3,5-dicarbonitriles

Knoevenagel condensation of N-hetaryl-substituted cyanoacetamides with aldehydes gave the corresponding (E)-N-hetaryl-2-cyanoacrylamides which were converted into (E)-N-alkyl-N-hetaryl-2-cyanoacrylamides and 6-amino-2-oxo-4-phenyl-1-(pyridin-2-yl)-1,2-dihydropyridine-3,5-dicarbonitriles. The structure of (E)-N-(pyridin-2-yl)-2-cyano-3-phenylprop-2-enamide was determined by X-ray analysis. Original Russian Text ? I.V. Dyachenko, V.D. Dyachenko, E.B. Rusanov, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 1, pp. 81–86.     

Synthesis,spectral and electrochemical properties of halogenated 6-alkyl-5-aryl-1-(benzo[d]thiazol-2-yl)-3-phenylverdazyls and 5-aryl-1-(benzo[d]thiazol-2-yl)-3-phenyl-6-vinylverdazyls

Chemistry of Heterocyclic Compounds - A sequence of alkylation, cyclization, and oxidation reactions was used to convert 5-aryl-1-(benzo[d]thiazol-2-yl)-3-phenylformazans into...     

Synthesis of Novel New 2-(2-(4-((3,4-Dihydro-4-oxo-3-aryl quinazolin-2-yl)methyl)piperazin-1-yl)acetoyloxy)-2-phenyl Acetic Acid Esters

Stereoselective diazotization of (S)-2-amino-2-phenyl acetic acid (L-phenyl glycine) (4) with NaNO₂ in 6% H₂SO₄ in a mixture of acetone and water gave optically pure (S)-2-hydroxy-2-phenyl acetic acid (L-mandelic acid) (5). Esterification, gave (S)-2-hydroxy-2-phenyl acetic acid esters (6). The latter was treated with chloroacetyl chloride in the presence of triethylamine (TEA) in dichloromethane (DCM) to yield (S)-2-chloroacetyloxy phenyl acetic acid ester (2). In another sequence, the reaction of 2-(chloromethyl)-3-arylquinazolin-4(3H)-one (9) treated with N-Boc piperazine, followed by deprotection of the Boc group, to obtain 3-aryl-2-((piperazin-1-yl)methyl) quinazolin-4(3H)-one (3). Reaction of 2 with 3 in the presence of K₂CO₃ and KI gave the title compound, 2-(2-(4-((3,4-dihydro-4-oxo-3-arylquinazolin-2-yl)methyl)piperazin-1-yl) acetoyloxy)-2-phenyl acetic acid esters (1). The structures of all the new compounds obtained in the present work are supported by spectral and analytical data.     

Synthesis,Crystal Structure and Luminescent Property of Cadmium Complex Based on 2-（2-（1Hbenzo[d]imidazol-2-yl）benzyl）-1H-benzo[d]-imidazole

The complex [Cd(bbb)Cl2]·DMF·H2O, where bbb is 2-(2-(1H-benzo[d]imidazol-2-yl)benzyl)-1H-benzo[d]imidazole, was synthesized and characterized by X-ray single-crystal structure analyses. For the complex: C24H25Cl2CdN5O2, Mr = 598.77, crystal system, triclinic, space group P1, a = 9.9878(12), b = 10.0008(12), c = 13.2217(15) , α = 80.674(2), β = 72.158(2), γ = 86.776(2)°, V = 1240.5(3) 3, Z = 2, Dc = 1.598 g/cm3, λ = 0.71073, μ(MoKα) = 1.127 mm–1, F(000) = 600, S = 1.04, R = 0.0905 and wR = 0.3088 for 4805 observed reflections with I 2σ(I). It is a neutral complex. The distorted tetrahedral geometry of cadmium ion is coordinated by two nitrogen atoms of ligand and two chloride ions. The complex emits blue green luminescence with emission peaks at 480 nm in DMF solution.     

An efficient one-pot expeditious synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazin-3-yl)-1H-pyrazol-5-amines via multicomponent approach

An efficient synthesis of 3-phenyl-1-(6-phenyl-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5-amines was accomplished by a simple, atom-economical, and multicomponent approach. Reaction of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol with various phenacyl bromides and benzoylacetonitriles in ethanol and catalytic amount of acetic acid afforded the titled compounds. The structures of newly synthesized compounds were confirmed by their analytical and spectral (IR, ¹H-NMR, ¹³C-NMR, and Mass) data.