Reaction Of O-phenylenediamine Research Articles

Synthesis of a Novel Tetracyclic Isoxazole by Intramolecular Nitrile Oxide Cycloaddition

Intramolecular cycloadditions have the great advantage of forming two rings simultaneously. We report the use of intramolecular [3 + 2] cycloaddition of the nitrile oxide derived from an N-propargylbenzimidazole oxime in the synthesis of a hitherto unreported tetracyclic isoxazole-containing ring system bearing “6-5-5-5”-membered ring fusions. The initial condensation was achieved through reaction of o-phenylenediamine with ethyl diethoxyacetate, followed by alkylation with propargyl bromide, deprotection of the acetal to the aldehyde, formation of an aldoxime, and intramolecular nitrile oxide cycloaddition (INOC). Characterization of the aldoxime and tetracyclic isoxazole is included herein.

Synthesis, crystal structure and Hirshfeld surface analysis of diaquabis(o-phenylenediamine-κ2 N,N′)nickel(II) naphthalene-1,5-disulfonate

The reaction of o-phenylenediamine (OPD), sodium naphthalene1,5-disulfonate (Na2NDS) and nickel sulfate in an ethanol–water mixture yielded the title compound, [Ni(OPD)2(H2O)2]·NDS or [Ni(C6H8N2)2(H2O)2](C10H6O6S2). This salt consists of a complex [Ni(OPD)2(H2O)2]2+ cation with two bidentate OPD ligands and trans aqua ligands, and a non-coordinating NDS2– anion, which is the double-deprotonated form of H2NDS. The NiII atom is situated at a center of inversion and exhibits a slightly tetragonally distorted {O2N4} octahedral coordination environment, with four shorter equatorial Ni—N bonds [2.0775 (17) and 2.0924 (18) Å] and a longer axial Ni—O bond [2.1381 (17) Å]. The OPD ligand is located about an inversion center and is nearly coplanar with the NiN4 plane [dihedral angle 0.95 (9)°]. In the crystal, the cations and anions are connected by charge-assisted intermolecular N—H...O and O—H...O hydrogen-bonding interactions into the tri-periodic network structure. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (44.1%), O...H/H...O (34.3%), C...H/H...C (14.8%) C...C (6.5%) (involving the cations) and O...H/H...O (50%), H...H (25%), C...H/H...C (15.3%), C...C (8.2%) (involving the anions) interactions.

Synthesis, anticancer for prostate cancer cells and antibacterial activity of new diazepine derivatives

In the current study, four new benzodiazepine derivatives were synthesized via a reaction of o-phenylenediamine with some chalcone derivatives. The synthesized compounds were characterized by 1H NMR and FT-IR spectroscopies. The antibacterial activity of the obtained diazepines was screened against E. coli, Bacillus subtilis, and Staphylococcus aureus. The results showed that compound 8 had the highest activity toward Bacillus subtilis and Staphylococcus aureus, while compounds 5 and 7 showed the highest activity toward E. coli. To support in vitro studies, docking studies have been performed to determine whether the title compounds (5–8) are inhibitors of the androgen receptor prostate cancer mutant H874Y ligand binding domain bound with testosterone and an AR 20–30 peptide (2Q7K), and the relationship between calculated energies and docking studies has been investigated. Among the synthesized diazepines, compound 5 was subjected to anticancer screening, where its activity against human prostate cancer (PC3) was tested. According to the obtained results, compound 5 has good anticancer activity against PC3.

Synthesis, Characterization, ADME Study and Antimicrobial Evaluation of New 1,2,3-triazole Derivatives of 2-phenyl benzimidazole.

Novel 2-amino benzimidazole derivatives containing amide, azide and 1,2,3-triazole moieties have been synthesized. Compound 3 was synthesized by reaction of o-phenylenediamine with p-aminobenzoic acid. Compound 3 was converted into amide by treatment with chloroacetyl chloride to get compound 4. Compound 4 and sodium azide were combined to create compound which has an azide group. Compound 5 was converted into 1,2,3-triazole derivatives by treatment with acetylene derivatives. FTIR, 1H-NMR, and Mass spectra have been used to confirm the chemical structures of various substances. By using a technique called well diffusion agar, the final products were examined in vitro to predict activity against two kinds of gram-positive bacteria and two kinds of gram-negative bacteria as well as the antifungal activity against Candida albicans fungus. All the final products exhibited moderate to potent activity compared to Trimethoprim and Fluconazole as reference antibacterial and antifungal drugs respectively. Swiss ADME was also used to undertake ADME tests to determine the bioavailability, drug-likeness and topological polar surface area of the synthesized molecule. The results showed that every chemical tested was absorbed orally and followed the Lipinski rule.

Cerium (IV) ammonium nitrate (CAN) promoted reaction: A selective synthesis of 2-arylbenzimidazoles via reaction of o-phenylenediamine and arylidene malononitriles at ambient temperature

Cerium (IV) ammonium nitrate (CAN) promoted reaction: A selective synthesis of 2-arylbenzimidazoles via reaction of o-phenylenediamine and arylidene malononitriles at ambient temperature

Synthesis and Characterization of new Mannich Bases for Pyrazole containing Benimidazole Ring

This research includes synthesis of new derivatives of benzimidazole , the compound (A1*) prepared by reaction of o-phenylene diamine with carbon disulfide in alcoholic potassium hydroxide. Then the compound (A1*) was reaction with ethyl chloroacetate and potassium hydroxide to give ester (A2*). Then preparation of hydrazide (A3*) by the reaction of (A2*) with hydrazine hydrate (80%). Then we used the hydrazide (A3*) to prepare pyrazole (A4), then preparation of mannich basses by reaction of compound (A4) with different primary aromatic amines and formaldehyde

Phosphite-imidazole catalyzed N-formylation and N-acylation of amines.

A novel and convenient method for the N-formylation reaction of amines with DMF as a formylating agent has been developed, utilizing a catalytic amount of diethyl phosphite/imidazole. Diethyl phosphite, as a nucleophilic catalyst, plays a significant role in this conversion. The presented method has a broad substrate scope, and various N-formyl products were obtained in good to excellent yields. Moreover, by using DMA instead of DMF, the N-acetylation reaction was also successful. The reaction of o-phenylenediamines with DMF afforded the corresponding benzimidazoles. Furthermore, N-sulfonyl amidines were obtained in good to excellent yields by the reaction of sulfonamides with DMF under similar conditions.

New 2-thiazol-5-yl-benzimidazoles: synthesis and determining of their potential as chemosensor reagents for polyvalent metal ions

Thiabendazole and its analogues are widely used and reasonably well studied in terms of their biological activity, while their potential as chemosensory compounds with optical detection and sensitivity to metal ions remains unexplored. On the other hand, the introduction of a thiazole ring into the heteroaromatic system of benzimidazole significantly expands the directions of practical application of benzimidazole derivatives. Thus, one of the important structural features of the benzimidazole-thiazole system is the presence of a chelate cavity. It is a potential center of complexation with metal ions, which, with their bright fluorescence, create additional opportunities for their use as luminescent probes and chemosensors. Considering the affinity of the sulfur atom for polyvalent heavy metals, sensors based on these compounds can be used in medically and environmentally oriented analysis of toxic metal compounds. In this publication, we focus on the synthesis of various 2- and 4-substituted 2-thiazol-5-yl-benzimidazoles, as well as the determination of their spectral-fluorescence properties. Therefore, we started from 2,4-dihalogen 5-formyl thiazoles, the methods of synthesis of which are well known. Their modification in 2nd position we have described in previous works. To obtain the target products, the Weidenhagen method was chosen, which consists in the reaction of o-phenylenediamine with an aromatic or aliphatic aldehyde under oxidation conditions. For creating such conditions copper acetate was used. The possibility of coordination of metal ions by the obtained compounds was established using electronic absorption and fluorescence spectroscopy. It was found that these compounds selectively form complexes with Cd2+ and Mg2+ ions. Our qualitative studies allow us to make conclusion that the benzimidazole-thiazole fragment is a promising coordination site for metal ions, which can be used in the design of fluorescent probes for the determination of Cd2+ and Mg2+ ions.

Green synthesis of nano-CuFe2O4/clinoptilolite and its use in benzodiazepine synthesis

In this research, a copper ferrite (CuFe2O4) nanocatalyst stabilized on clinoptilolite (CP) was prepared using green tea (Camellia sinensis) leaf extract. Fourier transform infrared spectra, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis, transmission electron microscopy (TEM), the Brunauer–Emmett–Teller (BET) method, thermogravimetric analysis and differential thermal analysis were used to characterize copper ferrite/CP. After fixation on CP, the crystallite size of copper ferrite was determined to be 48.7 nm using an XRD pattern and the Debye–Scherrer equation. Copper ferrite nanoparticles were successfully placed on CP as evidenced by FESEM and TEM images. Using the Barrett–Joyner–Halenda method, the average diameter of the catalyst pores was found to be 22.2 nm. Using the BET method, the catalyst surface area was estimated to be 43.7 m2/g. The catalytic activity of copper ferrite/CP in the production of benzodiazepine (the reaction of o-phenylenediamine with ketones) was examined. The experimental results showed that this catalyst performs well under mild reaction conditions. Using an external magnetic field, copper ferrite/CP was easily separated from the reaction product and can be reused without appreciably decreasing its catalytic activity.

Cu(OAc)2 mediated mild synthesis of 2-aminobenzimidazoles and 2-aminobenzoxazoles

An efficient and facile synthesis for 2-aminobenzimidazoles and 2-aminobenzoxazoles has been reported. Thioureas prepared from the reaction of o-phenylenediamines or 2-aminophenols and isothiocyanate derivatives, underwent desulfurization reaction smoothly under mild conditions in the presence of Cu(OAc)2, and afforded a variety of N-heterocyclic compounds in moderate to good yields.

Eco-friendly and Efficient Synthesis of 2-aryl-1-arylmethyl-1H-Benzo[d]imidazoles by using Sodium Hypochlorite

We are herein reporting a new ecofriendly, convenient and facile method for the synthesis of 2-aryl-1- arylmethyl-1H-benzo[d]imidazoles using sodium hypochlorite. Various imidazole derivatives were prepared from reaction of o-phenylenediamine with substituted aryl and heteroaryl aldehydes in aqueous ethanol at ambient temperature in one step with good to excellent yield. Easy reaction conditions, use of aqueous medium, easy isolation and purification of products make this method superior to other known methods.

English

2,3-Dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonohydrazide and its derivatives were synthesized and characterize by IR, 1H-NMR, 13C-NMR and mass spectrometry analytical methods. The 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl hydrazide (compound 1), was synthesized from the reaction of o-phenylenediamine with oxalic acid to obtain quinoxaline-2,3-dione, which was subjected to chlorosulfonation with chlorosulfonic acid to give 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl chloride. The 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl chloride was reacted with hydrazine hydrate to afford 2,3-dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl hydrazide (compound 1). The quinoxaline-6-sulfonohydrazone derivatives were synthesized by reacting compound 1 with substituted benzaldehydes or aromatic ketones. The chemical structures of the compounds prepared were confirmed by spectral data. The synthetic methodology was efficient and environmentally friendly; this was due to the fact that the work-up stage was carried out in water. Key words: 2,3-Dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl hydrazide, quinoxaline-2,3-dione, synthesis, substituted benzaldehydes, isatin, infrared, spectroscopy.

Dual-function 2D cobalt metal-organic framework embedded on paper as a point-of-care diagnostic device: Application for the quantification of glucose

Point-of-care (POC) diagnostic devices play significant roles in delivering vital surveillance information and providing proper and timely care to patients. There is a challenge in the development of new diagnostic tools to overcome their current shortcomings in terms of cost issues, accuracy and performance. Herein, a highly efficient paper-based analytical device based on a 2D metal-organic framework (MOF) has been reported for the colorimetric/fluorometric monitoring of glucose. Because of the inherent bifunctional activity of cobalt-terephthalate MOF (CoMOF) nanosheets, great improvements were made to the stability and performance of glucose oxidase (GOX) and to its catalytic effect on the reaction of o-phenylenediamine (OPD) and H2O2. The exceptional behavior of 2D CoMOF, along with a precise smartphone readout, led to the rapid and sensitive colorimetric/fluorometric detection of glucose in biological samples. Paper modified by CoMOF and GOX was stable for a long time, and a yellow-brown color and a high fluorescence emission were observed after the addition of a low volume of sample and OPD solutions. The probe showed a wide linear effectiveness range of 50 μM-15 mM, with colorimetric and fluorometric detection limits of 16.3 and 3.2 μM, respectively. Despite its great simplicity, the developed probe showed high performance and accuracy for the quantification of glucose.

Design, synthesis, antimicrobial activity and molecular docking studies of some novel di-substituted sulfonylquinoxaline derivatives

2,3-Dioxo-1,2,3,4-tetrahydroquinoxaline-6-sulfonyl chloride 1 was prepared via reaction of o-phenylene diamine with oxalic acid followed by chlorosulfonation with excess chlorosulfonic acid. A series of new sulfonylquinoxaline derivatives 2–6 were obtained upon reacting compound 1 with different types of amines. 2,3-Dichloro-6-morpholinosulfonylquinoxaline derivative 6 was subjected to further chemical reactions to afford many derivatives of 6-morpholino 2,3-disubstitutedquinoxalines, thus reaction of compound 6 with different secondary amines yielded mono and di secondary aminoquinoxaline derivatives 7–10 depending on the reactivity difference of the two chlorine atoms. Hydrazinolysis of compound 7 furnished hydrazino quinoxaline derivatives 11a-c. Additionally triazolo and pyrazolyl quinoxaline derivatives 12–14 were obtained through the reaction of compound 11a with phenyl isothiocyanate, formylpyrazole and ethyl acetoacetate. All the synthesized compounds were screened for their antibacterial and antifungal activities. Compounds 7a, 9b, 10a, 10c, 10f and 11c showed good to moderate antimicrobial activity against the tested Gram-positive, Gram-negative bacteria and fungi with MIC values ranging from 2.44 to 180.14 μM. Their MBC values were also evaluated using the same tested microorganisms. Moreover, screening against multi-drug resistant strains revealed the promiscuity of these new derivatives, especially compound 7a that showed comparable antibacterial activity (MIC 4.91–9.82 μM) with Norfloxacin (MIC 2.44–9.80 µM). Furthermore, these compounds were evaluated as DNA Gyrase inhibitors and the obtained results were in the range of 15.69–23.72 µM. Immunomodulatory effect was also investigated and compounds 7a, 11c, 10f, 10c, 10a and 9b showed high immunostimulatory action with ratio (142.6 ± 0.4, 135.7 ± 0.5, 117.8 ± 0. 39, 112.5 ± 0. 83, 86.4 ± 0. 47, 72.8 ± 0. 77) respectively. Molecular docking studies of the promising derivatives into DNA Gyrase binding site proved the usefulness of hybridizing quinoxaline scaffold with SO2 and morpholine moieties as a hopeful strategy in designing new DNA Gyrase binding molecules.

Determination of Iron in Licorice Samples by Slotted Quartz Tube Flame Atomic Absorption Spectrometry (FAAS) with Matrix Matching Calibration Strategy after Complexation with Schiff Base Ligand-Based Dispersive Liquid–Liquid Microextraction

In this study, a slotted quartz tube flame atomic absorption spectrometry (FAAS) system has been developed for the determination of iron after dispersive liquid–liquid microextraction. The iron coordinate complex was formed by using a ligand synthesized from the reaction of o-phenylenediamine and 5-bromosalicylaldehyde. Using the optimum conditions, the relative standard deviation was found to be 1.7% calculated from the lowest concentration of calibration plot, and the limits of detection and quantification were found to be 5.3 and 17.4 µg L−1, respectively. Other figures of merit of the developed method were satisfactory and an approximate 48-fold enhancement in detection power was recorded compared to the conventional FAAS system. The developed method was applied to licorice samples to evaluate the accuracy and applicability to real samples. The recovery values were in the range from 88% to 106% with low standard deviations.

Polybenzimidazole composite membranes containing imidazole functionalized graphene oxide showing high proton conductivity and improved physicochemical properties

Polymer composite membranes are fabricated using poly[2,2'-(m-phenylene)-5,5′-bibenzimidazole] (PBI) as a polymer matrix and imidazole functionalized graphene oxide (ImGO) as a filler material for high temperature proton exchange membrane fuel cell applications. ImGO is prepared by the reaction of o-phenylenediamine with graphene oxide (GO). The compatibility of ImGO with PBI matrix is found to be better than that of GO, and as a result PBI composite membrane having ImGO exhibits improved physicochemical properties and larger proton conductivity compared with pure PBI and PBI composite membrane having GO. For example, PBI composite membrane having 0.5 wt% of ImGO shows enhanced tensile strength (219.2 MPa) with minimal decrease of elongation at break value (28.8%) compared with PBI composite membrane having 0.5 wt% of GO (215.5 MPa, 15.4%) and pure PBI membrane without any filler (181.0 MPa, 34.8%). The proton conductivity of this membrane, at 150 °C under anhydrous condition, is 77.52 mS cm−1.

Formation of Benzodiazepines and Pyrazinylquinoxalines from Aromatic and Heteroaromatic Ketones via Deoximation

The report stated that the treatment of o-phenylenediamine with acetone dicarboxylic acid, acetone and acetophenone afforded 2,4,4-trimethyl-3H-5-hydro-1,5-benzodiazepine. However, direct reactions of o-phenylenediamine with oximes (acetone oxime, acetophenone oxime, and benzophenone oxime) as ketone equivalents did not occur. In the course of present investigations, it is found that dichloroamine-T can be an efficient reagent for the conversion of oximes into the corresponding carbonyl compounds. As a part of a research program related to the synthetic study of pharmacologically interesting benzodiazepine compounds, herein the synthesis of 1H-1,5-benzodiazepine derivatives from heteroaromatic ketones and acetone equivalents obtained using dichloroamine-T. On the other hand, when diamine (1,2-phenylene diamine or 1,2-naphthalene diamine) with heterocyclic ketone (acetyl pyridine or acetyl pyrazines) in the presenece of conc. HCl and SiO2 was refluxed, quinoxaline derivatives as yellow crystalline solids were isolated in high yields

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF SOME NEWER BENZIMIDAZOLE DERIVATIVES BY MANNICH REACTION

O-phenylenediamine and salicylic acid were used for the synthesis of 2-(1-(substituted phenylamino) methyl-1H benzo[d] imidazol-2-yl) phenol (2a-2h) derivatives by using various substituted aniline. In the first step, reaction of o-phenylenediamine and salicylic acid yielded 2-(1H-benzo[d]imidazol-2-yl) phenol (1), which on Mannich reaction with substituted aniline gave compounds (2a-2h). The structures of these compounds were characterized by IR, 1H NMR, mass spectral data and elemental analysis. Each analogue was tested in vitro for various types of pharmacological activity of this class of drugs including antibacterial, antifungal and anthelmintic activity. Among the synthesized compounds 2a act as vermifuge and no compound was found to be a vermicide. The compound 2c was found to be most active against E.coli and P. aeurigenosa and 2e be most active against B.subtilis and S.aureus. The derivative 2h shows good activity against C.albicans and A.niger.

Substituted benzimidazoles: A novel class of anti-tubercular agents

Reaction of O-phenylenediamine with phthalic anhydride gives 2H-benzimidazole -1-yl-3, 8 - benzpyrolidine - 2-one (I) This on condensation with anthranilic acid and 4-aminoacetophenone gives II. II on reaction with different aldehydes in presence of sodium hydroxide and ethanol stirred at room temperature for 24 h gives N-[4-(3-Aryl-acryloyl)–phenyl]–2-(1H– benzimidazol–2–yl)–benzamide (III-X). All the compounds have been characterized by elemental analysis, IR and NMR and Mass spectral analysis. All the compounds have been evaluated for their anti-tubercular activity against different stain of mycobacterium species. Keywords: Benzimidazole, O-phenylenediamine, Tuberculastatics, Antimicrobials, Aminobenzaldehyde.

Microwave assisted one pot synthesis of 2-ethylamino benzimidazole, benzoxazole and benzothiazole derivatives

A rapid and efficient one-pot method for the synthesis of 2-ethylamino benzimidazole, benzoxazole, and benzothiazole derivatives has been described. The reaction of o-phenylenediamines or o-aminophenols or 2-mercaptoanilines with EDC.HCl under microwave irradiation afforded the corresponding 2-ethylamino benzimidazole, benzoxazole and benzothiazole derivatives in excellent yields.