Hydrazine Hydrate In Presence Research Articles

A Regioselective One-Pot, Three Component Synthesis of 6-Aryl-4-cyano-3(2H)-pyridazinones in Water

A series of 4-cyano-3(2H)-pyridazinones bearing different aryl substituents in the 6-position of the pyridazinone ring was synthesized regioselectively using a novel efficient one-pot three component reaction of alkyl 2-cyanoacetates with arylglyoxals in the presence of hydrazine hydrate at room temperature in water.

Carbon nanotubes/magnetite hybrids prepared by a facile synthesis process and their magnetic properties

In this paper, a facile synthesis process is proposed to prepare multiwalled carbon nanotubes/magnetite (MWCNTs/Fe 3O 4) hybrids. The process involves two steps: (1) water-soluble CNTs are synthesized by one-pot modification using potassium persulfate (KPS) as oxidant. (2) Fe 3O 4 is assembled along the treated CNTs by employing a facile hydrothermal process with the presence of hydrazine hydrate as the mineralizer. The treated CNTs can be easily dispersed in aqueous solvent. Moreover, X-ray photoelectron spectroscopy (XPS) analysis reveals that several functional groups such as potassium carboxylate (–COOK), carbonyl (–C O) and hydroxyl (–C–OH) groups are formed on the nanotube surfaces. The MWCNTs/Fe 3O 4 hybrids are characterized with respect to crystal structure, morphology, element composition and magnetic property by X-ray diffraction (XRD), transmission electron microscopy (TEM), XPS and superconducting quantum interference device (SQUID) magnetometer. XRD and TEM results show that the Fe 3O 4 nanoparticles with diameter in the range of 20–60 nm were firmly assembled on the nanotube surface. The magnetic property investigation indicated that the CNTs/Fe 3O 4 hybrids exhibit a ferromagnetic behavior and possess a saturation magnetization of 32.2 emu/g. Further investigation indicates that the size of assembled Fe 3O 4 nanoparticles can be turned by varying experiment factors. Moreover, a probable growth mechanism for the preparation of CNTs/Fe 3O 4 hybrids was discussed.

Synthesis and Anti‐inflammatory Activity of Some Novel Pyrazole Derivatives of Gallic Acid

In the present study, a new series of [5‐substituted‐3‐(phenylamino)‐1H‐pyrazol‐1yl] (3,4,5‐trihydroxyphenyl)‐methanone (4a‐j) have been synthesized. 3, 4, 5‐Trihydroxy benzohydrazide (1) was synthesized from propyl gallate and hydrazine hydrate in presence of ethanol. Chalcones (2a‐j) were synthesized from acetanilide and various aromatic aldehydes in presence of ethanol and sodium hydroxide solution. By refluxing the compound (1) and compounds (2a‐j) in presence of ethanol yielded [5‐substituted‐3‐(phenylamino)‐4.5‐dihydropyrazol‐1yl] (3,4,5‐trihydroxy phenyl)‐methanone (3a‐j). The final compounds [5‐substituted‐3‐(phenylamino)‐1H‐pyrazol‐1yl] (3,4,5‐trihydroxyphenyl)‐methanone (4a‐j) were synthesized by treating compounds (3a‐j) with bromine water. The synthesized compounds have been characterized by IR, 1HNMR and Mass spectral data. The compounds were evaluated for in vivo anti‐inflammatory activity by carrageenan induced paw edema test. In general all compounds were found to exhibit good anti‐inflammatory activity.

Syntheses, Urease Inhibition, and Antimicrobial Studies of Some Chiral 3-Substituted-4-amino-5-thioxo-1H,4H-1,2,4-triazoles

Chiral 3-substituted-4-amino-5-thioxo-1H,4H-1,2,4-triazoles (5a-i) were synthesized. The target molecules were prepared by cyclization of the corresponding dithiocarbazinic acids, obtained from hydrazides, in the presence of hydrazine hydrate. The chiral hydrazides were in turn synthesized form L-amino acids. The structures of all the compounds were confirmed by modern spectroscopic techniques and purity ascertained by elemental analysis. The synthesized compounds 5a-i were evaluated for urease inhibition and found to exhibit varying degrees of urease inhibition activity showing IC(50) values ranging from 22.0 +/- 0.5 to 43.8 +/- 0.3 microM. Compound 5b was found to be the most active, exhibiting IC(50) = 22.0 +/- 0.5 microM comparable to the standard, thiourea (IC(50) = 21.0 +/- 0.1 microM). Triazoles 5a-i were also screened for their antimicrobial properties and promising antibacterial activities were observed against five pathogenic bacteria. However, all the compounds were devoid of any antifungal activity.

Synthesis and activity evaluation of 2-(1-naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles

Ethyl naphtho[2,1-b]furan-2-carboxylate (2) on reaction with hydrazine hydrate in presence of acid catalyst in ethanol medium affords naphtho[2,1-b]furan-2-carbohydrazide (3). The reaction of substituted acetophenones (4a-c) with aromatic aldehydes (5a-e) produces chalcones (6a-o) via the Claisen condensation. The reaction of naphtho[2,1-b]furan-2-carbohydrazide (3) with chalcones (6a-6o) in presence of acetic acid as catalyst in dioxane produces 1-(naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles (7a-o). The structures of newly synthesized compounds have been established by elemental analysis and spectral studies. The compounds 7a-o have been evaluated for their antimicrobial activity and some selected compounds evaluated for antiinflammatory, analgesic, anthelmintic, diuretic and antipyretic activities.

Reductive hydrothermal synthesis of La(OH)3:Tb3+ nanorods as a new green emitting phosphor

A reductive hydrothermal process with use of hydrazine hydrate as a protecting agent is proposed to synthesize La(OH)3:Tb3+ (Tb mol% = 0, 1, 5, 10, and 20) nanorods. The oxidation of Tb3+−Tb4+ was effectively prevented in the presence of hydrazine hydrate; hence the La(OH)3:Tb3+ nanorods exhibited much stronger green photoluminescence than the product prepared by the normal hydrothermal process. X-ray diffraction and transmission electron microscopy were employed to characterize the products, the results of which revealed that all the products were one-dimensional rod-like nanostructures of hexagonal structure (∼20 nm in diameter). The reductive hydrothermal process is desirable for the synthesis of other efficient Tb3+ doped nanophosphers.

Hydrothermal Synthesis and Characterization of Zirconia Nanocrystallites

This work focuses on the synthesis of tetragonal zirconia (ZrO2) nanocrystallites with diameters of 5 nm by a simple hydrothermal process in the presence of hydrazine hydrate. Structural characterization of the ZrO2 products using X‐ray diffraction and Raman spectroscopy revealed that the predominant crystal phase was the tetragonal phase. High‐resolution transmission electron microscopy images further showed that that the diameter of the majority of the tetragonal ZrO2 nanocrystallites was <5 nm. Furthermore, we discussed the mechanism of the hydrothermal process and the critical roles of hydrazine hydrate in the hydrothermal formation of the small‐sized ZrO2 nanocrystallites.

Catalytic behavior of nickel nanoparticles stabilized by lower alkylammonium bromide in aqueous medium

Heterogeneous synthesis of monodisperse pure nickel nanoparticles in aqueous medium has been carried out using cetyltrimethylammonium bromide and a lower alkylammonium bromide mixture of tetraethylammonium bromide and tetrabutylammonium bromide. The presence of cetyltrimethylammonium bromide alone results in the formation of a mixture of nickel hydroxide and nickel nanoparticles. The particles have been characterized using TEM, EDS, XRD, TGA-DSC and FTIR. The analysis showed that particles are spherical in shape, monodisperse, face-centered-cubic with average size about 15 nm and are stable in air up to 325 °C. The nanoparticles have been used as a solid phase catalyst for the reduction ofp-nitrophenol in the presence of hydrazine hydrate as reducing agent at different temperatures under varying conditions. The reduction process has been monitored by UV-vis analysis. The present study showed that nanoparticles are not poisoned after their repeated use in reduction of p-nitrophenol to p-aminophenol. TEM analysis also confirms that nanoparticles are stable in the dispersed medium for longer times.

Selected-control synthesis of hierarchical nickel structures

Nickel with urchinlike and sisallike structures has been successfully fabricated by a facile hydrothermal method. Investigations have revealed that the addition of surfactants and the presence of hydrazine hydrate and glycine are essential for the morphologies development. Furthermore, the magnetic properties of the samples with different morphologies have been studied, and the possible formation process is also discussed.

The influence of hydrazine hydrate on the photoconductivity of PbS thin film

High quality poly crystalline nanostructured PbS thin film has been deposited on a glass substrate by chemical deposition technique. The hydrazine hydrate as a reducing agent for lead ion has been used for preparation of the film. After deposition, the film has been annealed, and then the influence of hydrazine hydrate on the dark resistivity and photosensitivity of film have been investigated. It was found that in the presence of hydrazine hydrate in chemical deposition bath, the resistance of the prepared film increases to mega ohm. The measured room temperature detectivity of the film is 4 × 10 9 W −1 Hz 1/2 cm at the wavelength of 2.4 μm. The experimental results have shown that the PbS film, which has been prepared according to this procedure, can be applied as an infrared detector in the range of 1.0–3.0 μm.

Selenium-Containing Heterocycles from Isoselenocyanates: Use of Hydrazine for the Synthesis of 1,3,4-Selenadiazine Derivatives

Aryl isoselenocyanates 1 react with different phenacyl halides 2 in the presence of hydrazine hydrate in a one-pot reaction to give selenadiazines 3a–3f in good-to-excellent yields.

Synthesis and selective antitubercular and antimicrobial inhibitory activity of 1-acetyl-3,5-diphenyl-4,5-dihydro-(1h)-pyrazole derivatives

The new compounds 1-aryl-3-{1-phenyl-3-[p (methylthio)phenyl]pyrazol-4-yl}-2-propen-1-ones 2a?l were prepared by the condensation of 1-phenyl-3-[p (methylthio)phenyl]-4-formylpyrazole 1 with different aryl ketones. Compounds 2a?l in reaction with hydrazine hydrate yielded 3-aryl-5-{1-phenyl-3-[p-(methylthio)phenyl]pyrazol-4 yl}-4,5-dihydro-(1H)-pyrazoles 3a?l and in the presence of hydrazine hydrate in glacial acetic acid gave 1-acetyl-3-aryl 5-{1-phenyl-3-[p-(methylthio)phenyl]pyrazol-4-yl}-4,5 dihydro-(1H)-pyrazoles 4a?l. These compounds were tested in vitro for their antitubercular and antimicrobial activities. The in vitro antimycobacterial activity of the newly synthesized compounds was investigated against Mycobacterium tuberculosis H37RV (ATCC 27294) in BACTEC 12B medium using the ALAMAR radiometric system. The antimicrobial in vitro activity was tested against Bacillus coccous, Bacillus subtilis Escherichia coli, Proteus vulgaris and antifungal activity against Aspergillus niger. The structures of the synthesized compounds were assigned on the basis of elemental analysis IR, 1H NMR and mass spectral data.

A facile reduction of azoxyarenes with hydrazine hydrate/magnesium: formation of different products under different reaction conditions

Azoxyarenes on treatment with hydrazine hydrate in presence of magnesium turnings in methanol undergo reduction. The reactions have been carried under microwave irradiation as well as at reflux to ...

Facile, Product‐Selective Reduction of Azoxyarenes into Azoarenes or Hydrazoarenes by Aluminium/Hydrazine Hydrate

Azoxyarenes, on treatment with hydrazine hydrate in presence of aluminium powder in methanol, undergo reduction. The reactions have been carried under microwave irradiation as well at reflux to get the corresponding hydrazoarenes and azoarenes as reduced products. The reaction is very fast, which gives excellent yield of the product. Substituents such as OCH3, OC2H5, and Cl are unaffected.

Hydrothermal synthesis of M 2S 3 (M = Sb, Bi) bulk single crystals and nanorods

We report the synthesis of bulk prismatic single crystals of M 2S 3 (M = Sb, Bi) via a novel hydrothermal process, using SbCl 3 or BiCl 3 and sulfur as the raw materials at 180 °C for over 7 days in the presence of diethylammonium chloride (DEACl) or tetraethylammonium chloride (TEACl), and Sb 2S 3 nanorods through a similar process in the presence of hydrazine hydrate. The products were characterized by various techniques, including X-ray powder diffraction (XRD), X-ray single crystal diffraction and field emission scanning electronic microscope (FESEM). The possible growth mechanism of single crystals was also discussed.

Hydrothermal synthesis and characterization of NiTe alloy nanocrystallites

Transition metal alloy NiTe nanocrystallites was prepared through hydrothermal reaction of tellurium with nickel chloride in sodium hydroxide solution in the presence of hydrazine hydrate as a reducer. Nanocrystallites with different morphologies can be obtained in the temperature range 60–250°C. The products were characterized by X-ray diffraction, transmission electron microscopy and ICP-Atomic emission spectroscopy.

Hydrothermal synthesis of PbSe, PbTe semiconductor nanocrystals

Hydrothermal reaction of selenium or tellurium with lead acetate in sodium hydroxide solution in the presence of hydrazine hydrate as a reductive was investigated to prepare lead chalcogenides, Pb E ( E=Se, Te). Nanocrystals with different morphology could be obtained under mild conditions. Our experiment shows that source materials and reaction temperature play important roles in forming the objective products and controlling their morphologies. The formation of lead chalcogenides in our process is based on a direct elemental combination pathway. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM).

A New Solvothermal-Reduction Pathway to Nanocrystalline MTe (M = Zn, Pb)

Abstract A novel solvothermal-reduction pathway (SRP) to nanocrystalline metal tellurides (MTe, M = Zn, Pb) has been established by the reaction of metal salts with tellurium in various solvents in the presence of hydrazine hydrate(N2H4·H2O) as a reducing agent. Nanocrystallites with different morphologies such as cube particles and similar-rectangular flakes were obtained under mild conditions. The effects of solvents and temperature on the reactions were investigated.

3-Benzotellurepines: the first examples of tellurepines

Reaction of o-diethynylbenzene with sodium telluride in the presence of hydrazine hydrate gives 3-benzotellurepine 2, which is converted into the 3,3-dihalogeno derivatives 3 by treatment with sulphuryl chloride or bromine; these compounds are the first examples of tellurepines.

Synthesis of 1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinoline-2,4-dione

In the presence of hydrazine hydrate or sodium ethylate, ethyl 2-[(N-phenylcarbamoyl)amino]-5,6,7,8-tetrahydroquinoline-3-carboxylate is converted to 3-amino- or 3-phenyl-1,2,3,4,6,7,8,9-octahydropyrimido[4,5-b]quinoline-2,4-dione. Compounds analogous to the latter are also obtained during heating of 2-amino-5,6,7,8-tetrahydroquinoline-3-carboxylic arylamides with phenyl isocyanate or from their N-phenylcarbamoyl derivatives.