Reaction Of 2-aminopyridine Research Articles

ANTIMICROBIAL ACTIVITY OF PROTON SALTS OF 3-(SULFAMOYLPHENYLCARBAMOYL)ACRYLIC ACID DERIVATIVES WITH AMINOPYRIDINE DERIVATIVES

Ten proton transfer salts (9-18) were synthesized from the reaction of 2-aminopyridine (1), 2-amino-3/4/5/6-methylpyridines (2-5) and 3-aminomethylpyridine (6) with (E)-3-(3/4-sulfamoylphenylcarbamoyl)acrylic acid (7 and 8), respectively. Bacillus subtilis (wild culture), Candida albicans (ATCC 14053) (yeast), Enterococcus faecalis (ATCC 29212) (Gram positive), Escherichia coli (ATCC 25922), Listeria monocytogenes (ATCC 7644), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (NRRL B-767) (Gram negative) bacterial microorganisms have been tested against the antimicrobial evaluation of compounds (1–18). Vancomycin, Cefepime, Levofloxacin and the antifungal substance Fluconazole were used as antibacterial reference compounds for comparing the MIC values of 1-18. Compounds 1, 3-6, 8-13, 15, 17 and 18 for E. faecalis, 5 for B. subtilis, 1, 3-12, 15, 17 and 18 for S. aureus, 3, 9, 10, 13, 15 and 17 for L. monocytogenes, 16 for E. Coli and 4 for P. aeruginosa the best effect are observed. Proton transfer salts {9, 14, 15 and 17} were showed higher effect than Fluconazole while other compounds (except compounds 2 and 4) had similar effects with Fluconazole. The compounds 2 and 4 showed less activity than Fluconazole.

Anti-Breast Cancer Activity of Some Synthesized Pyrazole Derivatives Bearing Imidazo[1,2a]pyridine Moiety

A novel series of pyrazole derivatives containing imidazo[1,2-a]pyridine D1-D8 moiety has been synthesized. The reaction of 2-aminopyridine with 4-phenylphenacyl bromide and 4-bromophenacyl bromide gave the products A and A1, respectively. These products then reacted with DMF and POCl3 to obtain new aldehyde derivatives B and B1. These two aldehydes were condensed with various acetophenone substitutes to yield the corresponding chalcone derivatives C1-C10. Following this, the cycloaddition reaction with hydrazine hydrate provided new pyrazole derivatives D1-D8. The prepared compounds were verified by FT-IR, 1H NMR, and 13C NMR spectroscopy. Two of these derivatives (C5 and D1) were chosen to investigate their cytotoxic efficacy against breast cancer using the MTT assay.

Sonochemical Synthesis and In Silico Evaluation of Imidazo[1,2-a]Pyridine Derivatives as Potential Inhibitors of Sirtuins

Encouraged by the reported sirtuin modulating ability of an imidazopyridazine derivative the structurally relevant imidazo[1,2-a]pyridine framework was explored for the design and synthesis of prospective inhibitors of sirtuins. The synthesis of targeted imidazo[1,2-a]pyridine derivatives was carried out via a NBS (N-bromosuccinimide) promoted reaction of 2-aminopyridines with β-keto esters (or 1,3-dione derivatives) in PEG-400 under ultrasound irradiation. This sonochemical method afforded the desired product in good yield when 2-aminopyridines containing electron donating methyl group were employed whereas the corresponding products were obtained in low yields when the electron withdrawing chloro group was present in 2-aminopyridines. The use of 1,3-diones in place of β-keto esters generally afforded the corresponding products in moderate to low yields. The compounds obtained from 1,3-diones were evaluated in silico against SIRT1, 2 and 3 for their potential inhibitory properties against these proteins. The carbonyl group generally played an important role in the interaction of test compounds with the target protein via formation of H-bond(s) with the appropriate residue(s). The docking studies also indicated the selective inhibition of SIRT1 over SIRT2 and 3 by the compound 4a whereas the selective SIRT3 inhibition was specified for compound 3x. Additionally, the in vitro SIRT1 inhibition e.g. 66.7 ± 2.1, 76.8 ± 1.3, 51.9 ± 3.0 and 70.1 ± 1.9% shown by 3x, 4a, 4b and 4c, respectively at 10 µM corroborated the in silico findings concerning this protein.

Copper anchored on phosphorus g-C3N4 as a highly efficient photocatalyst for the synthesis of N-arylpyridin-2-amines

A copper modified phosphorus doped g-C3N4 (Cu/P-CN) has been prepared and identified as an efficient catalyst for the synthesis of N-arylpyridin-2-amine derivatives by the reaction of 2-aminopyridine and aryl boronic acid under the irradiation of blue light.

Microwave-promoted One-pot Synthesis of Imidazo[1,2-a]pyridines in Lemon Juice

Objective: A simple and highly efficient microwave-promoted procedure for the synthesis of imidazo[1,2-a]pyridine derivatives from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice was designed. The main advantages of this protocol, such as clean reaction profile, mild reaction condition, high yield, and minimum reaction time, were compared to other previously developed methods. Method: A mixture of aromatic ketones (1a-m) (0.005 m), N-bromosuccinimide (NBS) (0.005 m), and lemon juice (10 ml) was irradiated by microwave at 400-watt power at 85°C, and the formation of α- bromoketones was monitored by Thin Layer Chromatography (TLC). After completion of α-bromination, 2-aminopyridines (0.005 m) was added to the reaction mixture and it was further irradiated at the same reaction condition. After completion of the reaction, the reaction mass was poured in ice-cold water, the solid product obtained was filtered, washed with cold water, and recrystallized from aqueous ethanol. Result: In the present investigation, we have developed an environmentally benign, easy, and highly efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive features such as minimum reaction time, clean reaction profile, mild reaction condition, and green aspects such as avoid poisonous catalyst, hazardous solvents, ease of the work-up procedure, and higher yield. Conclusion: In the present investigation, we have developed an environmentally benign, easy, and highly efficient one-pot procedure for the synthesis of 2-phenylimidazo [1, 2-a] pyridines from the reaction of aromatic ketones, N-bromosuccinimide, and 2-aminopyridines in lemon juice as a natural acid catalyst and solvent under microwave irradiation. This new protocol offers very attractive features such as minimum reaction time, clean reaction profile, mild reaction condition, and green aspects such as no need for a poisonous catalyst and hazardous solvents, ease of work-up procedure, and higher yield.

Copper Iodide Nanoparticles Immobolized Porous Polysulfonamide: An Effective Nanocatalyst for Synthesis of Imidazo [1,2-a] Pyridines

An efficient route was developed for the synthesis of a new polymer, porous cross-linked poly(ethyleneamine)-polysulfonamide (PEA-PSA), as an organic support for the imobilization of CuI nanoparticles (PEA-PSA@CuI). The resulting catalyst works as an efficient recyclable heterogeneous catalyst for the synthesis of imidazo[1,2-a] pyridines from the reaction of 2-aminopyridine, aldehydes and phenylacetylene. The method possesses significant advantages including: easy purification, functional group tolerance, recyclability of the catalyst and synthesis of new derivatives in high to excellent yields and short reaction times.

Synthesis of 2,3-Dihydro-1H-imidazo[1,2-a]pyridinium Systems by Halocyclization of 1-Alkenyl(propargyl)-2-aminopyridinium Halides

Reaction of 2-aminopyridine with allyl bromide, methallyl chloride, 2-bromoallyl bromide, and propargyl bromide in acetone furnished 2-amino-1-allyl-, methallyl-, (2-bromoallyl)-, and propargylpyridinium halides. 2-Amino-1-allyl(methallyl)pyridinium halides reacted with bromine and iodine to form 2-halomethyl-2,3-dihydro-1H-imidazo[1,2-a]pyridinium systems. 2-Amino-1-(2-bromoallyl)pyridinium bromide underwent heterocyclization under the action of bromine, and did not react with iodine. 2-Amino-1-propargylpyridinium bromide reacted with bromine and iodine to form 2-halomemylene-2,3-dihydro-1H-imidazo[1,2-a]pyridinium systems.

Design, Synthesis, In vitro Cytotoxic Activity Evaluation, and Study of Apoptosis Inducing Effect of New Styrylimidazo[1,2-a]Pyridines as Potent Anti-Breast Cancer Agents.

This paper reports synthesis, cytotoxic activity, and apoptosis inducing effect of a novel series of styrylimidazo[1,2-a]pyridine derivatives. In this study, anti-cancer activity of novel styrylimidazo[1,2-a]pyridines was evaluated. Styrylimidazo[1,2-a]pyridine derivatives 4a-o were synthesized through a one-pot three-component reaction of 2-aminopyridines, cinnamaldehydes, and isocyanides in high yield. All synthesized compounds 4a-o were evaluated against breast cancer cell lines including MDA-MB-231, MCF-7, and T-47D using MTT assay. Apoptosis was evaluated by acridine orange/ethidium bromide staining, cell cycle analysis, and TUNEL assay as the mechanism of cell death. Most of the synthesized compounds exhibited more potent cytotoxicity than standard drug, etoposide. Induction of apoptosis by the most cytotoxic compounds 4f, 4g, 4j, 4n, and 4m was confirmed through mentioned methods. In conclusion, these results confirmed the potency of styrylimidazo[1,2-a]pyridines for further drug discovery developments in the field of anti-cancer agents.

Synthesis and Characterization of Thiazolo Pyridin-2-Amine and Their Schiff Bases

The efficient synthesis of thiazolo pyridine 2-amine(3) by reaction of 2-amino pyridine with ammonium thiocyanate(2). The reaction carried out in presence of ceric ammonium nitrate and Dimethyl Sulphoxide as a solvent. The aromatic aldehyde reacts with synthesized compound thiazolo pyridin-2-amine (3) by using catalytic amount of Ni (NO3)2 .6H2O at room temperature. Advantages of this protocol are its very good yields.

Glucokinase Activators Based on N-Aryl-N′-Pyridin-2-Ylurea Derivatives

A series of previously undescribed N-aryl-N′-pyridin-2-ylureas were prepared via the reaction of 2-aminopyridines with benzoyl azides and tested in vitro as activators of glucokinase. Statistically significant reductions of glucose levels as compared with controls were demonstrated for several compounds.

DFT calculation, biological activity, anion sensing studies and crystal structure of (E)-4-chloro-2-((pyridin-2-ylimino)-methyl)phenol

(E)-4-Chloro-2-[(pyridin-2-ylimino)methyl]phenol was synthesized in the reaction of 2-aminopyridine with 5-chlorosalicylaldehyde. The structure of compound was investigated by FTIR, UV?Vis, 1H-NMR, 13C-NMR and X-ray data. In addition, characterization of the compound was realized using theoretical quantum mechanical calculations and experimental spectroscopic methods. The molecular structure of the compound was confirmed using X-ray single-crystal data, NMR, FTIR and UV?Vis, which were in good agreement with the structure predicted by the theoretical calculations using the density functional theory (DFT). Moreover, the antimicrobial activity of the compound was investigated against some bacteria and yeast cultures by the broth microdilution test. UV?Vis spectroscopy studies of the interactions between the Schiff base and calf thymus DNA (CT-DNA) showed that the compound interacts with CT-DNA via electrostatic binding. The colorimetric response of the compound receptors was investigated before and after the addition of an equivalent amount of each anion to evaluate anion recognition properties.

Catalyst-free synthesis of novel 4H-indeno[1,2-b]furan-4-ones and furo[2,3-d]pyrimidines in water

ABSTRACTAn operationally simple, catalyst-free, and efficient protocol for the synthesis of novel 4H-indeno[1,2-b]furan-4-one and furo[2,3-d]pyrimidine derivatives by a one-pot reaction of 2-aminopyridines, 1,3-indandione, or barbituric acid and phenylglyoxal monohydrate in water at reflux, involving domino aldol condensation, Michael addition, and ring-closing reactions is described. This transformation has several advantages, including high yield, short reaction duration, simple workup, and simple purification.

Synthesis and biological evaluations of new nitric oxide-anti-inflammatory drug hybrids

Three novel series of nitroso derivatives (11–15), isoxazolopyrazoles (17a–c) and isoxazolo[3,4-d]pyridazines (18a–c) were prepared from the hydroxyimoyl chloride 10. In vitro COX1⧹2 inhibition activities were evaluated, both of 17b and 18a proved a promising inhibitory activity with IC50=1.12, 0.78μM in sequent. Carrageenan induced Paw edema, ulcer liability, nitric oxide (NO) release and histopathological study were determined. Most of the prepared compounds showed excellent activities. Reactions of 2-aminopyridine and enaminone with hydroxyimoyl chloride 10 were investigated and proved by 2D NMR. Molecular docking for most active compounds was operated giving a hint for compound–receptor interactions.

Tetrakis [N-(2-pyridyl) sulfonamide] di palladium: synthesize, X-ray diffraction, antibacterial properties and as a novel binuclear Pd-complex for coupling reactions

The N-(2-pyridyl) 4-toluene sulfonamide as a free ligand (PTS) was prepared from the reaction of 2-amino pyridine and 4-toluenesulfonyl chloride in the presence of potassium hydroxide solution 1 M as a base and THF was used as a solvent. The complex tetrakis [N-(2-pyridyl) sulfonamide] di palladium (1) (Pd2L4) was also prepared from the reaction of PdCl2(CH3CN)2 using (PTS) in the presence of NaOH 0.5 M and its application in Heck and Suzuki reactions. This complex consists of a binuclear unit consisting of four ligands linked to two palladium atoms via the nitrogen of pyridines ring and the nitrogen of sulfonamides. These compounds were confirmed by FT-IR and 1H NMR spectroscopy. Moreover, the structure of the complex was studied by single-crystal X-ray diffraction method. The green crystal of Pd2L4 [L = N-(2-pyridyl) sulfonamide](1) was found to crystallize in the monoclinic space group C2/c with a = 18.2013(19), b = 19.7544(16), c = 17.2898(19) A, β = 120.179(8) °; V = 5374.0(9) A3; Z = 4; the final R 1 = 0.0894, wR 2 = 0.1754 (or 5867 observed reflections and 318 variables). The Pd–Pd distance is 2.567(2) A. In addition, PTS and Pd2L4 presented different antibacterial behaviors. The free ligand was active against Staphylococcus aureus and Escherichia coli, but the complex was inactive against them.

An efficient and catalyst-free synthesis of N-arylidene-2-arylimidazo[1,2-a]pyridine-3-ylamine derivatives via Strecker reaction under controlled microwave heating

AbstractAn efficient one-pot multicomponent reaction of 2-aminopyridine with aromatic aldehydes and either benzoyl cyanide or cyanamide in pyridine under controlled microwave heating afforded N-aryldene-2-arylimidazo[1,2-a]-pyridine-3-ylamine derivatives. The reaction is catalyst free and is of high atom economy.

ChemInform Abstract: NaNO2/I2‐Mediated Regioselective Synthesis of Nitrosoimidazoheterocycles from Acetophenones by a Domino Process.

A regioselective synthesis of nitrosoimidazoheterocycles from the reaction of 2-aminopyridines and acetophenones in the presence of NaNO2 and I2 is described. The reaction is suggested to proceed by a domino process involving sequential imine formation, iodination, iodide displacement by the nitro group, and finally intramolecular cyclization. Reaction of these 3-nitrosoimidazo[1,2-a]pyridines with aldehydes in the presence of Fe/AcOH furnished 5-substituted pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolines by reduction of the nitroso group followed by a Pictet–Spengler reaction in one pot. The synthesized compounds were assessed for their antibacterial and antifungal activities.

ChemInform Abstract: Nano‐NiFe2O4 Catalyzed Microwave Assisted One‐Pot Regioselective Synthesis of Novel 2‐Alkoxyimidazo[1,2‐a]pyridines under Aerobic Conditions

Abstractstarting from 2‐aminopyridine, β‐nitrostyrenes, and various alcohols

Synthesis and Crystal Structures of Some Pyridyl Aminothiazole and Thiazolidin-2-ylidene Benzamide Derivatives

Background: Thiazoles and their derivatives are attracting continuing interest over the years because of their varied biological activities. Thiazole and in particular the 2-amino thiazole moiety has been incorporated into a wide variety of therapeutically interesting candidates including antibacterial, anti-HIV, hypertension, anti-inflamenmatory, anti-viral and anticancer agents. Methods: Several methods for the synthesis of thiazole derivatives have been developed. The most widely used method being the Hantzch’s synthesis. In this paper, we describe an efficient one-pot method for the synthesis of some thiazolidin-2-ylidene benzamide and aminothiazole derivatives via condensation of 3-aminopyridine or 2- aminopyridine with phenacyl bromide and benzoyl isothiocyanates. Results: The reaction of 3-aminopyridine, benzoyl isothiocyanates, and phenacyl bromide in the presence of triethylamine yields thiazolidin-2-ylidene benzamides, which upon heating in acetic acid produce pyridyl aminothiazole derivatives. Also the pyridyl aminothiazole derivatives were obtained by the reaction of 2-aminopyridine with benzoyl isothiocyanates and phenacyl bromide in the presence of triethylamine. The molecular structures of the 4-chloro-N-(4-hydroxy-4-phenyl- 3-(pyridin-3-yl)thiazolidin-2-ylidene)benzamide, phenyl(4-phenyl-2-(pyridin-3-ylamino)thiazol-5-yl)methanone and (4- phenyl-2-(pyridin-2-yl amino)thiazol-5-yl)(o-tolyl)methanone, have been fully determined by means of single crystal Xray diffraction methods. Conclusion: In summary, present study reports one-pot synthesis of thiazolidin-2-ylidene substituted benzamide and pyridyl aminothiazole derivatives via condensation of 3-aminopyridine or 2-aminopyridine with phenacyl bromide and substituted benzoyl isothiocyanates. The single crystal X-Ray diffraction analysis reveals unequivocally the exact identity of the compounds. Keywords: 2-aminopyridine, 2-aminothiazole, 3-aminopyridine, benzoyl isothiocyanates, phenacyl bromide, thiazolidin-2- ylidene benzamide.

ChemInform Abstract: Chemistry of 3‐Oxo‐N‐(pyridin‐2‐yl)butanamide and Related Compounds

AbstractReview: 73 refs.

ChemInform Abstract: Recent Developments in the Synthesis of Imidazo[1,2‐a]pyridines

AbstractReview: [151 refs.