Synthesis Of New Mono Research Articles

3-Aminopyrazolo[3,4-b]pyridine: Effective Precursor for Barium Hydroxide-Mediated Three Components Synthesis of New Mono- and Bis(pyrimidines) with Potential Cytotoxic Activity.

In this study, an efficient one-pot procedure for preparing a new series of pyrazolo[3,4-b]pyridine-fused pyrimidines was described. The target hybrids were developed through a three-component reaction of 3-amino-1H-pyrazolo[3,4-b]pyridine, benzaldehydes, and acetophenones (molar ratio 1 : 1 : 1). The best conditions for the previous reaction were 2.5 equivalents of barium hydroxide in DMF at 150 °C for 6 h. New bis(pyrimidines) were synthesized in high yields using a similar one-pot reaction protocol with some modifications. Thus, two equivalents of each of the appropriate acetophenones and 3-aminopyrazolopyridine were reacted with one equivalent of the appropriate bis(aldehydes). The reaction was carried out at 150 °C for 8 h using 4.5 equivalents of barium hydroxide in DMF. Repeating the previous reaction with the appropriate bis(acetyl) derivatives and benzaldehydes resulted in good yields of the target bis(pyrimidines). The in vitro cytotoxic activity of new pyrimidines against the MCF-7, HEPG2, and Caco2 cell lines was evaluated using the reference doxorubicin (IC50 values of 4.34-6.97 μM). Hybrid 6h had the best activity against Caco2 and MCF-7 cell lines, IC50 values of 12.62 and 14.50 μM, respectively. The IC50 values for hybrids 6c, 6e, and 6f against MCF-7 and Caco2 cell lines were 23.99-41.69 and 33.14-43.33 μM, respectively. Furthermore, hybrid 6e displayed IC50 value of 20.06 μM HEPG2 cell lines, while the hybrids 6c, 6f and 6h exhibited IC50 values ranging between 26.29-50.51 μM. Furthermore, hybrid 6e had an IC50 value of 20.06 μM for the HEPG2 cell lines, whereas hybrids 6c, 6f, and 6h had IC50 values ranging from 26.29 to 50.51 μM.

New antiparasitic flexible triaryl diamidines, their prodrugs and aza analogues: Synthesis, invitro and invivo biological evaluation, and molecular modelling studies.

Dicationic diamidines have been well established as potent antiparasitic agents with proven activity against tropical diseases like trypanosomiasis and malaria. This work presents the synthesis of new mono and diflexible triaryl amidines (6a-c, 13a,b and 17), their aza analogues (23 and 27) and respective methoxyamidine prodrugs (5, 7, 12a,b, 22 and 26). All diamidines were assessed invitro against Trypanosoma brucei rhodesiense (T.b. r.) and Plasmodium falciparum (P.f.) where they displayed potent to moderate activities at the nanomolar level with IC50s=11-378nM for T.b. r. and 4-323nM against P.f.. Invivo efficacy testing against T.b. r. STIB900 has shown the monoflexible diamidine 6c as the most potent derivative in this study eliciting 4/4 cures of infected mice for a treatment period of >60 days upon a 4×5mg/kg dose i. p. treatment. Moreover, thermal melting analysis measurement ΔTm for this series of diamidines/poly (dA-dT) complexes fell between 0.5 and 19°C with 6c showing the highest binding to the DNA minor groove. Finally, a 50 ns molecular dynamics study of an AT-rich DNA dodecamer with compound 6c revealed a strong binding complex supported by vdW and electrostatic interactions.

Synthesis of biological based hennotannic acid-based salts over porous bismuth coordination polymer with phosphorous acid tags.

In this paper, a novel porous polymer capable of coordinating to bismuth (PCPs-Bi) was synthesized. The Bi-PCPs was then reacted with phosphorous acid to produce a novel polymer PCPs(Bi)N(CH2PO3H2)2 which is shown to act as an efficient and recyclable catalyst. The mentioned catalyst was applied for the efficient synthesis of new mono and bis naphthoquinone-based salts of piperidine and/or piperazine via the reaction of hennotannic acid with various aldehydes, piperidine and/or piperazine, respectively. The structure of the resulting mono and bis substituted piperazine or piperidine-based naphthoquinone salts was thoroughly characterized spectroscopically. The electrochemical behavior of the products was also investigated. The presented protocol has the advantages of excellent yields (82–95%), short reaction times (4–30 min) and simple work-up.

Effective photodegradation of organic pollutantsin the presence of mono and bi-metallic complexes under visible-light irradiation

The synthesis of new mono and bi-metallic complexes such as Zn (II) and Ag-Zn (II) complexes with organic functional group-based ligand (OFL) presented in the current work along with the exploration of their applicability in the photocatalytic degradation of organic dyes under visible-light irradiation. The Zn (II) complex obtained from organic functional group-based ligands, complexed with the donor atoms such as S and N under solvothermal conditions and Ag-Zn (II) complex formed through Ag ions complexed with pyridine ring nitrogen atom. These Zn(II)-complexes were systematically analyzed using the physicochemical studies and other spectroscopic techniques. From these facts, it is clarified that the complexes show square planar geometry with organic functional group-based ligands coordination via mercapto and azomethine groups. The reported complexes were used for the photodegradation of standard organic dye pollutants used in various textile and food processing industries. The complex [Ag-Zn(DCMPPT)(H2O)(OAc)] shows higher photocatalytic activity than [Zn(DCMPPT)(H2O)] because of the high surface area, low bandgap energy and further visible-light available for the initiation of ●OH radicals. To identify the active species in the photocatalytic process, the mechanism process also reported for the fast photodegradation of organic dye pollutants in the existence of some radical quenchers.

Exploring the relationship between structure and activity in BODIPYs designed for antimicrobial phototherapy.

A synthetic strategy to BODIPY dyes is presented giving access to a range of new compounds relevant in the context of antimicrobial photodynamic therapy (aPDT). BODIPYs with the 8-(4-fluoro-3-nitrophenyl) and the 8-pentafluorophenyl substituents were used for the synthesis of new mono- and dibrominated BODIPYs. The para-fluorine atoms in these electron-withdrawing groups facilitate functional modification via nucleophilic aromatic substitution (SNAr) with a number of amines and thio-carbohydrates. Subsequently, the antibacterial phototoxic activity of these BODIPYs has been assessed in bacterial assays against the Gram-positive germ S. aureus and also against the Gram-negative germ P. aeruginosa. The bacterial assays allowed to identify substitution patterns which ensured antibacterial activity not only in phosphate-buffered saline (PBS) but also in the presence of serum, hereby more realistically modelling the complex biological environment that is present in clinical applications.

Practical one‐pot, two‐step protocol for the ultrasound‐assisted synthesis of new mono‐ and bis‐pyrrolidine‐2,5‐diones containing sulfonamide moiety

AbstractA simple and efficient preparation of novel series of mono‐ and bis‐pyrrolidine‐2,5‐diones containing sulfonamide moiety was described. The strategy involved sequential one‐pot sulfonylation‐nucleophilic substitution procedure and was found effective under ultrasound activation and used for the first time. This approach allows the synthesis of products in good to excellent yields in short reaction time.

C-O and C-N Functionalization of Cationic, NCN-Type Pincer Complexes of Trivalent Nickel: Mechanism, Selectivity, and Kinetic Isotope Effect.

This report presents the synthesis of new mono- and dicationic NCN-NiIII complexes and describes their reactivities with protic substrates. (NCN is the pincer-type ligand κ N, κ C, κ N-2,6-(CH2NMe2)2-C6H3.) Treating van Koten's trivalent complex (NCN)NiIIIBr2 with AgSbF6 in acetonitrile gives the dicationic complex [(NCN)NiIII(MeCN)3]2+, whereas the latter complex undergoes a ligand-exchange reaction with (NCN)NiIIIBr2 to furnish the related monocationic complex [(NCN)NiIII(Br)(MeCN)]+. These trivalent complexes have been characterized by X-ray diffraction analysis and EPR spectroscopy. Treating these trivalent complexes with methanol and methylamine led, respectively, to C-OCH3 or C-NH(CH3) functionalization of the Ni-aryl moiety in these complexes, C-heteroatom bond formation taking place at the ipso-C. These reactions also generate the cationic divalent complex [(NCN)NiII(NCMe)]+, which was prepared independently and characterized fully. The unanticipated formation of the latter divalent species suggested a comproportionation side reaction between the cationic trivalent precursors and a monovalent species generated at the C-O and C-N bond formation steps; this scenario was supported by direct reaction of the trivalent complexes with the monovalent compound (PPh3)3NiICl. Kinetic measurements and density functional theory analysis have been used to investigate the mechanism of these C-O and C-N functionalization reactions and to rationalize the observed inverse kinetic isotope effect in the reaction of [(NCN)NiIII(Br)(MeCN)]+ with CH3OH/CD3OD.

Antibacterial activities of mono-, di- and tri-substituted triphenylamine-based phosphonium ionic liquids

We report the synthesis of new mono, di and tri phosphonium ionic liquids and the evaluation of their antibacterial activities on both Gram-positive and Gram-negative bacteria from the ESKAPE-group. Among the molecules synthesized some of them reveal a strong bactericidal activity (MIC = 0.5 mg/L) for Gram-positive bacteria (including resistant strains) comparable to that of standard antibiotics. A comparative Gram positive and Gram negative antibacterial activities shows that the nature of counter-ion has no significant effects. Interestingly, the increase of phosphonium lateral chains (from 4 to 8 carbons) results in a decrease of antibacterial activities. However, the increase of the spacer length has a positive influence on the activity on both Gram-positive and Gram-negative bacteria except for E. aerogenes. Finally, the increased charge density has no effect on the Gram-positive antibacterial activities (MIC between 2 and 4 mg/L) but seems to attenuate (except for P. aeruginosa) the discrimination between Gram-positive and Gram-negative. Overall these results suggest a unique mechanism of action of these triphenylamine-phosphonium ionic liquid derivatives.

Novel nano-size and crab-like biological-based glycoluril with sulfonic acid tags as a reusable catalyst: its application to the synthesis of new mono- and bis-spiropyrans and theirin vitrobiological studies

Herein novel crab-like biological-based glycoluril with sulfonic acid tags was prepared in nano-size form and fully characterizedviaseveral techniques.

Synthesis and Characterisation of Heterobimetallic Lanthanoid O‐Based Cluster/Cages

The synthesis of new mono‐ and bimetallic lanthanoid cluster compounds is reported. The metal‐to metal ratios of tetra‐ and pentanuclear clusters were determined by energy‐dispersive X‐ray spectroscopy (EDS). The EDS results show that, for an equal proportion of lanthanide salts introduced, different metal‐to‐metal ratios are achieved in the clusters. This ratio appears to be dependent on the size and electron density of the metal atoms. Studies realized the best conditions to achieve a 1:1 ratio.

Synthesis of new mono‐ and bisorganophosphorus proline derivatives with P–C–N moieties

AbstractThe various methods of aminomethylation of some PH‐acids with proline and their derivatives are investigated. The numerous derivatives of proline and corresponding phosphonates, phosphonites, phosphinates, and phosphorane with proline moieties are presented.

Synthesis of fluorinated triazole and isoxazole derivatives by electrochemical fluorination

Partially fluorinated triazole derivatives were synthesized through anodic fluorination of alkynes having arylthio group and following Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) with benzyl azide. The other route toward the fluorinated triazoles, namely the anodic fluorination of triazole derivatives once prepared by advanced CuAAC of the alkyne and azide above was also investigated. It was shown that these two routes are mutually complementary methodology for the synthesis of new mono- and difluoromethyltriazole derivatives. Furthermore, Cu(I)-catalyzed isoxazole synthesis from fluorinated alkynes and imidoyl chloride was demonstrated.

Different strategies in electrochemical synthesis of new mono and di-substituted hydroquinone and benzoquinone

Electrochemical syntheses of 2-indolyl-5-arylsulfonyl-p-benzoquinone derivatives were carried out in two successive oxidation steps. The first involves the oxidation of hydroquinone, 4-(piperazin-1-yl) phenol) and 1-(4-(4-hydroxyphenyl) piperazin-1-yl) ethanone in the presence of arylsulfinic acids as nucleophiles. Our voltammetric data indicate that electrochemically generated p-benzoquinone participates in Michael addition reaction with arylsulfinic acids leading to the 2-(arylsulfonyl) benzene-1,4-diols. The second consists of the oxidation of 2-(arylsulfonyl) benzene-1,4-diols in the presence of 1,2-dimethylindole and the formation of 2-indolyl-5-arylsulfonyl-p-benzoquinone derivatives as the final products. A plausible mechanism for the synthesis of 2-indolyl-5-arylsulfonyl-p-benzoquinone derivatives is also presented.

ChemInform Abstract: One‐Pot Three‐Component Synthesis of New Mono‐ and Bis‐1,2,3‐triazole Derivatives of 2‐Benzimidazolethiol with a Promising Inhibitory Activity Against Acidic Corrosion of Steel.

AbstractThe corrosion inhibition efficiency of the new heterocycles is investigated on steel grade API 5L X52 in 1M HCl employing electrochemical impedance spectroscopy.

Synthesis, Characterization, Reactivity of η 3-allylPd(L)(X), Where X = Cl and L = Imidazolylphosphine and Their Application in Aryl Amination Reactions

Synthesis of new mono-(imidazolylphosphine) palladium chloride complexes is reported. Imidazolyl phosphines reacted with allypalladium chloride dimer to form monophosphine palladium(II) complexes. Some of these complexes readily ionize to form stable square planar complexes in which the heterocyclic nitrogen coordinates to Pd, whereas in other cases, the acidity of the N–H proton was explored. Finally, activity of complexes as catalysts for aryl amination reactions was also investigated.

One-Pot Three-Component Synthesis of New Mono- and Bis-1,2,3-triazole Derivatives of 2-Benzimidazolethiol with a Promising Inhibitory Activity against Acidic Corrosion of Steel

A series of new mono- and bis-1,2,3-triazole derivatives of 2-benzimidazolethiol were synthesized by three-component copper(I)-catalyzed 1,3-dipolar cycloaddition. The desired heterocycles were obtained in good yields and fully characterized. The corrosion inhibition efficiency of new heterocyclic compounds was investigated on steel grade API 5L X52 in 1 M HCl using electrochemical impedance spectroscopy. The results revealed that these new organic compounds show promising inhibition properties for the corrosion of steel in acidic media.

Carbonyl complexes of transition metals with stabilized germylenes

Germylenes based on substituted diethylenetriamine (1), diethanolamines (2, 3) and pyridine-containing dialcohols (4, 5) were used as ligands in molybdenum and tungsten carbonyl complexes. Synthesis of new mono- and disubstituted (cis- or trans-) germanium(II) containing molybdenum (8, 9, 14, 15, 17) and tungsten (6, 7, 10–13, 16) carbonyl complexes were described. Composition of the complexes obtained was established by elemental analysis data and their structures were investigated by multinuclear NMR spectroscopy, IR and X-ray diffraction analysis (7, 13 and 17). The germylenes based on dialkanolamines and pyridine-containing dialcohols (O-ligands) give cis-digermanium complexes in contrast to the germylenes based on diethylenetriamines (N-ligands) which form trans-digermanium complexes.

Synthesis of mono‐ and bisorganophosphorus substituted amides of unsaturated carboxylic acids with PCHNC(O) and antioxidant fragments

AbstractThe convenient methods for the synthesis of new mono‐ and bisorganophosphorus substituted amides of unsaturated carboxylic acids with PCHNC(O) and antioxidant fragments, starting from Arbuzov reaction of the highly reactive adducts of corresponding imines and acyl chlorides with trimethylsilyl phosphites are proposed. Some properties of the new synthesized mono‐ and bisorganophosphorus substituted amides are presented. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:27–31, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/.20748

Synthesis of new mono and bis amides projected as potential histone deacetylase (HDAC) inhibitors

In our ongoing efforts to discover new potent histone deacetylase (HDAC) inhibitors as promising anticancer candidates, we designed and synthesized a small collection of 3-substituted amines possessing macro heterocyclic skeletons bearing variable-length tails. As a metal binder domain, all the compounds possess an amide function suitable for Zn2+ chelation in the enzyme active site. A combination of solution and solid phase techniques were employed to synthesize the compounds and, as the key synthetic step to obtain the rings, a ring closing metathesis (RCM) reaction was adopted. The putative affinity of the compounds for the histone deacetylase-like protein (HDLP) model receptor active site was explored through docking calculations, and we also report preliminary studies on their pharmacological properties.

Synthesis of Trinuclear, Dinuclear and Mononuclear Carbamato‐Zinc Complexes from Tetranuclear Precursors: A Top‐Down Synthetic Approach to New Carbamates

AbstractIn this work we report on the synthesis of new mono‐, bi‐ and trinuclear carbamato‐Zn complexes by reaction of the tetranuclear precursor [ZnEt(O2CNR2)]4 (R = iPr and iBu) with the nitrogen bases pyridine, N,N,N′,N′‐tetramethylguanidine (tmg) and bis(N,N,N′,N′‐tetramethylguanidino)naphthalene (btmgn). The only reaction product obtained with pyridine is the dinuclear complex [(py)ZnEt(O2CNR2)]2. In the case of reaction of [ZnEt(O2CNR2)]4 with tmg, the dinuclear species [(tmg)ZnEt(O2CNR2)]2 (for molar ratios of 1:4) and the mononuclear bis‐carbamato complex [(tmg)2Zn(O2CNR2)2] (for molar ratios of 1:8) were obtained. Finally, the mono‐ and trinuclear carbamates [(btmgn)ZnEt(O2CNR2)] and [(btmgn)Zn3Et3(O2CNR2)3] were formed in the reaction between [ZnEt(O2CNR2)]4 and btmgn (molar ratios 1:4 and 1:2, respectively). All products were structurally characterized by X‐ray diffraction. Using this top‐down approach the synthesis of a variety of oligonuclear carbamato‐Zn complexes becomes possible. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)