Hydrazine Moiety Research Articles

Selective Fluorescent Detection of Aspartic Acid and Glutamic Acid Employing Dansyl Hydrazine Dextran Conjugate

Highly water soluble polymer (DD) was prepared and evaluated for its fluorescence response towards various amino acids. The polymer consists of dansyl hydrazine unit conjugated into dextran template. The conjugation enhances higher water solubility of dansyl hydrazine moiety. Of screened amino acids, DD exhibited selective fluorescence quenching in the presence of aspartic acid (Asp) and glutamic acid (Glu). A plot of fluorescence intensity change of DD against the concentration of corresponding amino acids gave a good linear relationship in the range of 1 × 10(-4) M to 25 × 10(-3) M. This establishes DD as a potential polymeric sensor for selective sensing of Asp and Glu.

ChemInform Abstract: Functionalization of Chromones Through an Aza‐Baylis—Hillman‐Type Reaction.

AbstractApplication of the aza‐Baylis—Hillman reaction of 3‐formylchromones with dialkyl azodicarboxylates results in substitution of the formyl group with a hydrazine moiety.

ChemInform Abstract: Design, Synthesis and Anticancer Activity of 4‐Morpholinothieno[3,2‐d]pyrimidine Derivatives Bearing Arylmethylene Hydrazine Moiety.

AbstractMost of the synthesized compounds show moderate to significant cytotoxicity and high selectivity against one or more cell lines.

Synthesis and Selective Human Monoamine Oxidase B Inhibition of Heterocyclic Hybrids Based on Hydrazine and Thiazole Scaffolds

A new scaffold of hydrazothiazoles has been designed as monoamine oxidase (MAO) inhibitors combining the hydrazine moiety of iproniazid and the thiazole nucleus of glitazones, a class of peroxisome proliferator-activated receptor (PPAR)γ agonists recently co-crystallized with human MAO-B. The resulting derivatives were synthesized and assayed to evaluate their in vitro activity against both the A and B isoforms of hMAO. All compounds were shown to be selective hMAO-B inhibitors with IC(50) values in the low micromolar/high nanomolar range. Such results suggest that the hydrazothiazole scaffold could be considered as an interesting pharmacophore for the future design of new lead compounds as coadjuvants for the treatment of neurodegenerative diseases.

Synthesis, mesomorphic and gelation properties of 7-alkoxycoumarin-3-carbonyl hydrazine

A series of coumarin derivatives, 7-alkoxycoumarin-3-carbonyl hydrazine (nCCH), which possessed a hydrazine moiety at the end of the molecule was prepared and was characterised by infrared and 1H-nuclear magnetic resonance spectra, electrospray ionisation-mass spectrometry and elemental analysis. All the compounds exhibited enantiotropic mesophases with temperature domains of 67–82°C and 46–82°C on heating and cooling processes, as well as favourable gelability to kinds of organic solvents. The effect of the length of the alkoxy chain on mesomorphic and gelation properties was discussed. The studies revealed that hydrogen bonding between the nCCH molecules was one of the main driving forces for the formation of the gel and thermotropic mesophases.

Structural Evaluation and Antibacterial Sensitivity of Iron (III) Complexes of 4-<i>n</i>-hexyloxybenzoylhydrazine with Some Aliphatic and Aromatic

The condensation reaction of N-alkylidene or N-arylidene-(4-n-hexyloxy)benzoylhydrazone [L] (1-7) where, R= formaldehyde (1), acetaldehyde (2), butyraldehyde (3), cinnamaldehyde (4), 4-N,N-dimethylaminobenzaldehyde (5), 2-hydroxybenzaldehyde (6) and 4-methoxybenzaldehyde (7) with Fe(III) chloride hexahydrate afforded octahedral (8-9) [Fe(L3).nH2O] and square-pyramidal (10-14) [Fe(L2)Cl.nH2O] complexes. The complexes (8-10) were obtained in presence of pyridine and the complexes (11-14) were obtained by the direct reaction of the Schiff’s bases with Fe3+ ion. The complexes were characterized by magnetic moment measurement, UV-visible, infrared, 1H-NMR and TGA (Thermo gravimetric analysis) studies. The Schiff’s bases containing small alkyl group at the hydrazine moiety formed octahedral complexes, while the bulky/aryl/substituted aryl moiety, yielded five coordinated square-pyramidal complexes. The complexes were found to be quite stable and decomposition of the complexes ended with ferric oxide as final product. Complexes (10) and (13) showed no activity against all the bacteria. Complexes (8), (9) and (12) showed resistance while the complex (14) manifested intermediate antibacterial activity.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.9807 J. Sci. Res. 4 (3), 635-64 (2012)

Design, Synthesis and Anticancer Activity of 4-Morpholinothieno[3,2-<i>d</i>]pyrimidine Derivatives Bearing Arylmethylene Hydrazine Moiety

Three series of 4-morpholinothieno[3,2-d]pyrimidine derivatives containing arylmethylene hydrazine moiety (11a-f, 13a-k and 15a-h) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed. The synthesized compounds were evaluated for their cytotoxicity against three cancer cell lines (H460, HT-29, MDA-MB-231). Most of them exhibited moderate to significant cytotoxicity and high-selectivity against one or more cell lines, especially compounds 11c, 13b, 15f and 15g possessing dramatically increased cytotoxicity as compared with the positive controls, which were further evaluated for six other cancer cell lines and one normal cell line. The most promising compound 11c, bearing 3,4-methylenedioxy phenyl group, showed remarkable cytotoxicity against H460, HT-29 and MDA-MB-231 cell lines with IC(50)values of 0.003 µM, 0.42 µM and 0.74 µM, which was 1.6- to 290-fold more potent than GDC-0941.

Combination of hydrazine polyanion strategy and ring-closing metathesis in the synthesis of heterocycles

An efficient method for the synthesis of cyclic hydrazine derivatives starting from disubstituted hydrazines is reported. The method is based on the selective alkylation of hydrazine dianions with bromoalkenes and subsequent cyclization using Grubbs’ catalysts. The described method provides fast and easy access to the substrates for ring-closing metathesis and the corresponding heterocycles containing a hydrazine moiety. The scope and limitations of the new method are also demonstrated.

The State of the Art of Pyrazole Derivatives as Monoamine Oxidase Inhibitors and Antidepressant/Anticonvulsant Agents

Monoamine oxidase plays a significant role in the control of intracellular concentration of monoaminergic neurotransmitters or neuromodulators and dietary amines. The rapid degradation of these molecules ensures the proper functioning of synaptic neurotransmission and is critically important for the regulation of emotional and other brain functions. The development of human MAO inhibitors led to important breakthroughs in the therapy of several neuropsychiatric disorders. Different families of heterocycles containing 2 or 4 nitrogen atoms have been used as scaffolds for synthesizing selective monoamine oxidase inhibitors, but the early period of the MAO-inhibitors started with hydrazine derivatives. Pyrazole, pyrazoline, and pyrazolidine derivatives can be considered as a cyclic hydrazine moiety. This scaffold also displayed promising antidepressant and anticonvulsant properties as demonstrated by different and established animal models. Diversely substituted pyrazoles, embedded with a variety of functional groups, are important biological agents and a significant amount of research activity has been directed towards this chemical class.

The Catalytic Asymmetric Diels–Alder Reactions and Post‐cycloaddition Reductive Transpositions of 1‐Hydrazinodienes

The Catalytic Asymmetric Diels–Alder Reactions and Post‐cycloaddition Reductive Transpositions of 1‐Hydrazinodienes

Novel Hydrazine Molecules as Tools To Understand the Flexibility of Vascular Adhesion Protein-1 Ligand-Binding Site: Toward More Selective Inhibitors

Vascular adhesion protein-1 (VAP-1) belongs to a family of amine oxidases. It plays a role in leukocyte trafficking and in amine compound metabolism. VAP-1 is linked to various diseases, such as Alzheimer's disease, psoriasis, depression, diabetes, and obesity. Accordingly, selective inhibitors of VAP-1 could potentially be used to treat those diseases. In this study, eight novel VAP-1 hydrazine derivatives were synthesized and their VAP-1 and monoamine oxidase (MAO) inhibition ability was determined in vitro. MD simulations of VAP-1 with these new molecules reveal that the VAP-1 ligand-binding pocket is flexible and capable of fitting substantially larger ligands than was previously believed. The increase in the size of the VAP-1 ligands, together with the methylation of the secondary nitrogen atom of the hydrazine moiety, improves the VAP-1 selectivity over MAO.

Pathways for cyclizations of hydrazine-derived 2-(2-cyanovinyl)-3-oxo-cyclohex-1-ene enolates

The introduction of a hydrazine functionality into 2-(2-cyanovinyl)-3-oxo-cyclohex-1-ene enolates results in their spontaneous cyclizations with participation of the hydrazine moiety. Depending on the reaction conditions used, the hydrazine-derived enolates are transformed into derivatives of 1-arylpyridine-2-one-3-carbonitriles or pyrazoloquinolinones in a one-pot synthesis. They also react with anilines to give the corresponding N1-substituted pyridine-2-one-3-carboxamides. Product characterization was performed by means of spectroscopic and X-ray diffraction studies. In addition, for structure elucidation purposes, a counter synthesis of 1-arylaminopyridine-2-one-3-carboxamide was also carried out.

A new hydrogen bonding motif involved in self-recognition in the solid state by functionalised macrocycles

Self-recognition within the crystal lattices of three functionalised macrocycles results in the formation of arrays of remarkably similar hermaphroditic pairs of macrocycles. In the case of two of the macrocycles containing acylhydrazine substituents, a hitherto unknown recognition pattern is found in the interaction of the hydrazine moiety with crown-ether oxygen atoms.

Synthesis, crystal structures and theoretical studies of four Schiff bases derived from 4-hydrazinyl-8-(trifluoromethyl) quinoline

The molecular structures of three new Schiff base compounds of the form R – hydrazinyl-8-(trifluoromethyl)-quinoline, and the fourth, a structurally related hydrate, have been examined by X-ray crystallography, B3LYP/6-3 G (d) and Hirshfeld surface and fingerprint calculations. Compound ( I), C 18H 14F 3N 3, crystallizes in the tetragonal, I 4 1 / a space group ( z = 32) while compounds ( II) – C 18H 13BrF 3N 3; P 2 1 / c, ( III) – C 18H 14F 3N 3O·H 2O; P 2 1 / c, and ( IV) – C 22H 16F 3N 3; P 2 1/n , are monoclinic ( z = 4). In ( I) there are two independent molecules in the asymmetric unit. In compounds ( I), ( II) and ( IV) R = ethylidene 1-phenyl, ethylidene 3-bromophenyl and ethylidene naphthalen-2-yl while ( III) consists of a 4-[(1E)-1-{2-[8-(trifluoromethyl)quinolin-4-yl]-hydrazinylidene}ethyl]-phenol hydrate. In all four compounds the trifluoromethyl group lies in the plane of the quinoline ring and the methyl group is in the plane of the hydrazine moiety. The mean plane of the quinoline ring is planar with hydrazine moiety in ( II) and ( IV) and twisted slightly in ( I) and ( III). In all four compounds weak π-stacking interactions are observed between ring centroids of the various naphthalene(benzene) and quinoline (benzene and pyridine) rings which contribute to the crystal packing. A comparison of the angles between mean planes of the benzene and quinoline rings in the crystal and with the DFT theoretical calculation as well as inclusion of strong and weak intermolecular hydrogen-bond interactions has been included for each molecule. Hirshfeld surface analysis for visually analyzing intermolecular interactions in crystal structures employing 3D molecular surface contours and 2D fingerprint plots have been used to examine molecular shapes.

2-aryl-5-arylsulfanyl-1,3-oxazole-4-carboxylic acids and their derivatives

A convenient preparative procedure has been developed for the synthesis of previously unknown 2-aryl-5-arylsulfanyl-1,3-oxazole-4-carboxylic acids and their functional derivatives from accessible multicenter substrates of the general formula Cl2C=C(NHCOR)C(O)OMe. The products turned out to be suitable for various subsequent transformations. Some oxazole-4-carboxylic acid hydrazide derivatives containing a substituted oxazol-5-yl fragment at the N2 atom in the hydrazine moiety underwent recyclization on heating in acetic acid; as a result, one oxazole ring was converted into 1,3,4-oxadiazole.

A Rapid Microwave-Assisted Procedure for Easy Access to Nx Polydentate ­Ligands for Potential Application in α-RIT

Heterocycles bearing a hydrazine moiety react with bisaldehydes or bisketones to afford new N x polydentate ligands suitable for a-radioimmunotherapy. We developed a fast and efficient method using microwave-assisted technology to obtain chelators with variable size and number of coordination centers which were fully characterized. The complexation efficiency with astatine will be assessed.

1,3,5,7-Tetramethyl-8-aminozide-difluoroboradiaza-s-indacene as a new fluorescent labeling reagent for the determination of aliphatic aldehydes in serum with high performance liquid chromatography

A BODIPY-based fluorescent derivatization reagent with a hydrazine moiety, 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), has been designed for aldehyde labeling. An increased fluorescence quantum yield was observed from 0.38 to 0.94 in acetonitrile when it reacted with aldehydes. Twelve aliphatic aldehydes from formaldehyde to lauraldehyde were used to evaluate the analytical potential of this reagent by high performance liquid chromatography (HPLC) on C(18) column with fluorescence detection. The derivatization reaction of BODIPY-aminozide with aldehydes proceeded at 60 degrees C for 30min to form stable corresponding BODIPY hydrazone derivatives in the presence of phosphoric acid as a catalyst. The maximum excitation (495nm) and emission (505nm) wavelengths were almost the same for all the aldehyde derivatives. A baseline separation of all the 12 aliphatic aldehydes (except formaldehyde and acetaldehyde) is achieved in 20min with acetonitrile-tetrahydrofuran (THF)-water as mobile phase. The detection limits were obtained in the range from 0.43 to 0.69nM (signal-to-noise=3), which are better than or comparable with those obtained by the existing methods based on aldehyde labeling. This reagent has been applied to the precolumn derivatization followed with HPLC determination of trace aliphatic aldehydes in human serum samples without complex pretreatment or enrichment method.

Thermoanalytical and spectroscopic studies on hydrazinium lighter lanthanide complexes of 2-pyrazinecarboxylic acid

The new hydrazinium lanthanide metal complexes of 2-pyrazinecarboxylic acid (HpyzCOO) of the formulae (N2H5)2[Ln(pyzCOO)5] · 2H2O (1), where Ln = La or Ce and (N2H5)3[Ln(pyzCOO)4(H2O)] · 2NO3 (2), where Ln = Pr, Nd, Sm or Dy have been synthesized and characterized by physico-chemical methods. The IR absorption bands of N–N stretching at 960 cm−1 unambiguously prove the existence of N2H5+ ions. The bonding parameters β, b1/2, % δ and η, have been calculated from the electronic spectroscopic (hypersensitive) bands of Pr(III) and Nd(III) complexes. All the complexes undergo endothermic followed by exothermic decomposition to leave the respective metal oxides as the end products. However, the DTA of the complexes 2 demonstrate rather sharp peak than the complexes 1, owing to overwhelming exothermicity, which may be due to the loss of both hydrazine and nitrate moieties in the same step. The X-ray powder diffraction studies reveal the existence of isomorphism among the member complexes.

Intramolecular Hydro‐N‐alkylation of Hydrazones and Oxime Ethers: Synthesis of Novel D‐Secoestrone Isoquinuclidines via Domino 1,5‐Hydride Shift/Cyclization

AbstractThe direct transformation of a benzylic C(sp3)–H bond into a C–N bond from steroidal hydrazones 10b, 10f–l and oxime ethers 28b–d under the action of a stoichiometric amount of Lewis acid is reported. The mechanism of functionalization to give novel types of isoquinuclidine derivatives 25b, 25f–l and 32b–d is assumed to involve an intramolecular domino 1,5‐hydride transfer/cyclization sequence. Azomethine imines 23b, 23f–l and oxyiminium ions 29b–d are proposed as intermediates, which undergo 1,5‐hydride shift to give the tertiary carbocation 24b, 24f–l or 31b–d. The nucleophilic addition of the hydrazine or hydroxylamine moiety to the benzylic C‐9 carbon led to bridged azaestrone derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Preparation and antitubercular activities in vitro and in vivo of novel Schiff bases of isoniazid

Structural modification of the frontline antitubercular isonicotinic acid hydrazide (INH) provides lipophilic adaptations ( 3– 46) of the drug in which the hydrazine moiety of the parent compound has been chemically blocked from the deactivating process of N 2-acetylation by N-arylaminoacetyl transferases. As a class, these compounds show high levels of activity against Mycobacterium tuberculosis in vitro and in tuberculosis-infected macrophages. They provide strong protection in tuberculosis-infected mice and have low toxicity. With some representatives of this class achieving early peak plasma concentrations approximately three orders of magnitude above minimum inhibitory concentration, they may serve as tools for improving our understanding of INH-based treatment modalities, particularly for those patients chronically underdosed in conventional INH therapy.