Hydrazine Research Articles

Synthesis, structure elucidation, SC-XRD/DFT, molecular modelling simulations and DNA binding studies of 3,5-diphenyl-4,5-dihydro-1H-pyrazole chalcones

Deoxyribonucleic acid (DNA) acts as the most important intracellular target for various drugs. Exploring the DNA binding interactions of small bioactive molecules offers a structural guideline for designing new drugs with higher clinical efficacy and enhanced selectivity. This study presents the facile synthesis of pyrazoline-derived compounds (4a)-(4f) by reacting substituted chalcones with hydrazine hydrate using formic acid. The structure elucidation of substituted pyrazoline compounds was carried out using 1H-NMR, FT-IR and elemental analyses. While the crystal structures of two compounds (4a) and (4b) have been resolved by single-crystal X-ray diffraction (SC-XRD) analysis. Hirshfeld surface analysis also endorsed their greater molecular stability. Computational calculations at DFT/B3LYP/6-311++G(d,p) were executed to compare the structural properties (bond angle and bond length) and explore reactivity descriptors, frontier molecular orbitals (FMO), Mulliken atomic charges (MAC), molecular electrostatic potential (MEP) and electronic properties. All the compounds were evaluated for DNA binding interactions by UV-Vis spectrophotometric analysis. The results revealed that compounds (4a)-(4f) bind to DNA via non-covalent binding mode having binding constant values ranging from 1.22 × 103 to 6.81 × 104 M−1. The negative values of Gibbs free energy also proved the interaction of studied compounds with DNA as a spontaneous process. The findings of molecular docking simulations depicted that these studied compounds showed significant binding interactions with DNA and these results were consistent with experimental findings. Compound (4b) was concluded as the most potent compound of the series with the highest binding constant (4.95 × 104) and strongest binding affinity (-8.48 kcal/mol). Communicated by Ramaswamy H. Sarma

Green synthesis of novel pyrano[2,3-c]pyrazole-5-carbonitrile analogues by using Fe5(PW10V2O40)3 nanocatalyst through a one-pot Knoevenagel condensation and Michael addition mechanism

A swift and green one-pot method was improved for the preparation of new pyranopyrazole analogues using iron-doped heteropoly acid [(Fe5(PW10V2O40)3] (FePWV) as an efficient catalyst at room temperature and ethanol as the solvent. The one-pot, multi-component reaction combining substituted aldehyde, malononitrile,ethyl acetoacetate, and hydrazine hydrate produces remarkable yields (varying from 88 % to 98 %) for this highly selective technique. Using P-XRD, TGA, BET, FT-IR, TEM, and SEM studies, the synthesized FePWV catalyst was fully characterized. Several spectroscopic methods, including 1H NMR, 15N NMR, 13C NMR, and HRMS, were used to confirm the target molecules' structural information.This environmentally benign method also has other benefits, such as operational simplicity, a stable catalyst with great reusability (up to 7 times), quick reaction times (<20 min), and the absence of chromatographic separations. The proposed method is sustainable and affordable as a result of these properties taken together.

Ionic liquid based electroless silver plating bath for Printable circuit boards (PCBs) finishing

Immersion silver-plating technique is typically used for uniform coating on printed circuit boards (PCB) for finishing. Herein, we report an unconventional protocol for preparation of non-toxic immersion silver-plating solution/bath. The solution was prepared through electrolysis using ionic liquid (1, 3-disulfonic acid imidazolium hydrogen sulfate [Dsim] [HSO4]) as electrolyte, metallic silver (Ag) as anode and copper as cathode. As a result of electrolysis, IL-capped aqueous charged silver ion (Ag+) solution [colloidal Ag-IL adduct solution] is obtained. Presence of Ag+ in solution was verified by cyclic voltammetry (CV) experiments. Chemical reduction of Ag+ with Hydrazine Hydrate (NH2-NH2·H2O) yielded AgNPs. The AgNPs analyzed through dynamic light scattering (DLS) exhibiting 269.99 ± 14.2 nm size with Polydispersity Index (PDI) 0.126. The metallic copper strip immersed into the solution and a shiny silver plated surface obtained within 1–5 min at room temperature. Film thickness can be controlled by varying time of immersion. The corrosion rate was found to be 0.0012 mm/a by Tafel fitting. The solution is stable for the months without losing efficiency whereas the recovered IL used five times without significant loss in efficiency.

Hydrodeoxygenation of vanillin to 2-methoxy-4-methylphenol over carbon dots supported Pd catalyst

Vanillin hydrodeoxygenation (HDO) was studied in water and methanol using palladium-decorated carbon dots (Pd/CDs). The catalyst was synthesized from photo-reduction of palladium acetate using CDs as the reducing and dispersion agent, while CDs were produced via microwave treatment of glucose and urea. Pd/CDs were characterized with XRD, TEM, FT-IR, XPS, BET and ICP-OES. The selectivity to 2‑methoxy-4-methylphenol (MMP), at vanillin conversion of 100 % after 4.0 h was 98.8 % at 140 °C under 4.0 MPa of H2 in water with 4.58 wt.% of Pd/CDs. The stability of Pd/CDs was also investigated after four times recycle under the optimal reaction conditions. CDs supported Pd reduced with NaBH4 and hydrazine hydrate (Pd/CDs-S and Pd/CDs-H) and other carbonaceous materials (active carbon and OH functionalized multi-walled carbon nanotube) supported Pd (Pd/AC and Pd/CNTs) were also investigated for comparison. The highest selectivity to MMP achieved by Pd/CDs produced via photoreduction brings a novel use of this type of catalyst in the conversion of biomass into value-added chemicals and materials.

Design, synthesis, chemical and biological evaluation of 2,5,5-trisubstituted-1,2-thiazepan-6-one 1,1-dioxides

In this article, we designed and synthesized a series of novel 2,5,5-trisubstituted (including spirocyclic) 1,2-thiazepan-6-one 1,1-dioxides (put simply, γ,γ-disubstituted β-keto ε-sultams), prepared a number of derivatives and evaluated their cytotoxic activity against MDA-MB-231 breast cancer cell line. In particular, alkylation of N-monosubstituted methanesulfonamides with α,α-disubstituted β-halogenated esters (including cyclic representatives) afforded the corresponding N-mesylated β-amino acid esters. The latters were involved in CSIC (Carbanion-mediated Sulfonamide Intramolecular Cyclization) reaction to give the target γ,γ-disubstituted β-keto ε-sultams (including spirocyclic representatives) in synthetically useful yields. This class of compounds can be considered as valuable building blocks since they possess carbonyl functionality and an EWG-activated methylene group capable of further functionalization. For instance, the condensation with DMFDMA afforded the corresponding α-dimethylaminomethylidene derivatives – the direct precursors for the heterocyclization reactions. Their treatment with hydrazine hydrate or guanidine hydrochloride provided the corresponding pyrazolo- and pyrimidofused ε-sultams. Despite the prepared β-keto ε-sultams showing weak cytotoxicity against the MDA-MB-231 breast cancer cell line, their pyrazolofused derivatives appeared perspective pharmacological templates with stable cytotoxic effects. Moreover, β-keto ε-sultams and their heterofused derivatives form water-soluble conjugates with branched polymers based on dextran-polyacrylamide (D-PAA) that can be used as the transport module for targeted drug delivery in biological media.

5‐N,N‐Diarylaminothiazoles with Electron‐Accepting Groups: Synthesis, Photophysical Properties, and Their Application for the Detection of Hydrazine Hydrate

Abstract5‐N,N‐diarylaminothiazoles containing cyano and nitro groups were synthesized using the Pd‐catalyzed Buchwald‐Hartwig amination reaction with good yields. The cyano group in the resultant thiazole was reduced to a formyl group. This was then subjected to the Knoevenagel condensation reaction, leading to the formation of thiazoles with a dicyanovinyl group. The nitro group in the thiazole was reduced to an amino group, which was subsequently reacted with triphosgene, yielding a thiazole with an isocyanate group. These thiazoles, with their electron‐accepting properties, demonstrated absorption and emission spectra at longer wavelengths. Notably, the thiazole containing the dicyanovinyl group displayed a red emission. Tests for the detection of hydrazine, a hazardous volatile organic compound, were conducted using the synthesized thiazoles. The results showed that the dicyanovinyl group effectively responded to hydrazine hydrate, evidenced by changes in the absorption and emission spectra. This change in color was also visibly detectable to the naked eye.

Novel triazolo pyridine derivatives and their anti cancer activity

A series of novel triazole functionalized trifluoromethyl pyridine derivatives was prepared starting from pyridine 1. Compound 1 on reaction with sulphuric acid gave compound 2 which on chlorination followed by hydrazine hydrate and obtained compound 3 and 4. Compound 4 on reaction with diverse substituted aliphatic and aromatic acid chlorides produced amide derivatives 4a-h and 5a-h. All the final compounds were evaluated for anti cancer activity against four human cancer cell lines such as HeLa - Cervical cancer (CCL-2); COLO 205- Colon cancer (CCL-222); HepG2- Liver cancer (HB-8065); MCF7 - Breast cancer (HTB-22). Promising compounds 4f and 4g were identified.

Synthesis and Antibacterial Evaluation for Some New Schiff-bases Derived from P-aminoacetanilide

Derivatives of Schiff-bases possess a great importance in pharmaceutical chemistry. They can be used for synthesizing different types of bioactive compounds. In this paper, derivatives of new Schiff bases have been synthesized from several serial steps. The acid (I) was synthesized from the reaction of dichloroethanoic acid with 2 moles of p-aminoacetanilide. New acid (I) converted to its ester (II) via the reaction of (I) with dimethyl sulphate in the present of anhydrous of sodium carbonate and dry acetone. Acid hydrazide (III) has been synthesized by adding 80% of hydrazine hydrate to the new ester using ethanol as a solvent. The last step included the preparation of new Schiff-bases (IV-VIII) by the reaction of acid hydrazide with appropriate aromatic aldehydes and using glacial acetic acid as a catalyst. New derivatives were diagnosed by FT-IR, and by mass and 1HNMR spectroscopy (some of them). Derivatives (IV-VIII) were screened for their antibacterial against E. Coli (G-) and staph. aureus (G+). All tested compounds were found to have activity against the two kinds of bacteria.

Synthesis and Molecular Docking Studies of Some Fluorinated 2-Aminopyrimidines, Pyrazoles and Isoxazoles as Possible Anti-cancer Agents

The reaction of a-fluoro-oxoketene dithioacetals (2) with guanidinium nitrate, hydrazine hydrate, and hydroxyl amine hydrochloride in the presence of sodium ethoxide in ethanol under reflux conditions produced new series of fluorinated 2-aminopyrimidines, pyrazoles, and isoxazoles. In silico study was carried out to explore the binding potential of all the synthesized compounds toward the cancer target receptors (EGFR and IGF1R). It is worth noting that 4-fluoro-5- (methylthio)-3-(naphthalen-4-yl)isoxazole (5h) had a higher affinity for both targets. In particular, the synthesized compound showed crucial interatomic interactions with IGF1R along with two hydrogen bond interactions (LYS1030 and ASP1150). Further, experimental investigation of this molecule will be an interesting direction to take to develop a new anti-cancer agent.. KEYWORDS :Anti-cancer activity, Fluorinated 2-aminopyrimidines, Isoxazoles and Pyrazoles, Molecular Docking Studies.

Inducing mutations using hydrazine hydrate, dimethyl sulfoxide and electric shock on three varieties of bread wheat (Triticum aestivum L.)

Inducing mutations using hydrazine hydrate, dimethyl sulfoxide and electric shock on three varieties of bread wheat (Triticum aestivum L.)

New Synthesis of 3-Aminohydantoins via Condensation of Hydrazines with Isocyanates Derived from α-Amino Esters

AbstractA new, simple, and efficient method for the synthesis of 3-aminohydantoins was reported in two steps, starting from the corresponding l -amino esters. Commercially available α-amino esters were converted into the corresponding isocyanate derivatives, which were then subjected to the condensation reaction with hydrazine hydrate and arylhydrazines, in the presence of DMAP and DIPEA. This method provides the corresponding 3-aminohydantoins in moderate and good yields under a simple and practical protocol.

Synthetic Transformation of 4-fluorobenzoic Acid to 4-fluorobenzohydrazide Schiff Bases and 1,3,4-Oxadiazole Analogs having DPPH Radical Scavenging Potential

Aims: Synthesis of 4-fluorobenzohydrazide Schiff bases and 1,3,4-oxadiazole analogs has a DPPH radical scavenging potential. Background: Synthetic antioxidants are widely used because they are effective and cheaper than natural antioxidants. Based on the literature survey, this present study is mainly focused on the study of the free radical scavenging activity of the Schiff base and oxadiazole motifs. Methods: In this research work, Schiff’s base (4a-4g) and 1,3,4-oxadiazole (5a-5g) derivatives based on 4-fluorobenzoic acid were synthesized through multistep reactions. Initially, 4-fluorobenzoic acid was esterified in the presence of sulphuric acid (H2SO4) in ethanol solvent, and then it was reacted with an excess of hydrazine hydrate to obtain the desired 4-fluorobenzohydrazide. Various aromatic aldehydes were reacted with 4-fluorobenzo hydrazide in the presence of a catalytic amount of acetic acid to obtain the desired hydrazones. Finally, different substituted hydrazones were cyclized in the presence of iodine and potassium carbonate in DMSO to obtain substituted 1,3,4-oxadiazoles. The progress of all reactions was checked using thin-layer chromatography. The compounds were recrystallized from ethanol with good yield. The synthesized compounds were characterized with the help of EI-MS and 1H-NMR spectroscopy. Results: The synthesized Schiff bases (4a-4g) and oxadiazole derivatives (5a-5g) of 4-fluorobenzoic acid demonstrated good free radical scavenging activity. Among the series, Compound 4f (IC50 = 25.57 ± 7.41 μM), showed comparable activity when compared with the standard Vitamin C (IC50 = 19.39 ± 12.57 μM). Similarly Compound 4a (IC50 = 40.90 ± 1.92 μM), 4b (IC50 = 34.77 ± 1.03 μM), 4c (IC50 = 90.2 ± 2.90 μM), 4e (IC50 = 78.62 ± 9.64 μM), 4g (IC50 = 80.65 ± 1.80 μM), 5a (IC50 = 52.67 ± 4.98 μM) and 5f (IC50 = 89.45 ± 9.11 μM) showed moderate antioxidant activity. Furthermore compounds, 4d (IC50 = 102.55 ± 10.4 μM), 5b (IC50 = 123.76 ± 12.34 μM), 5d (IC50 = 701.62 ± 1.06 μM), and 5e (IC50 = 102.87 ± 7.98 μM) displayed less significant anti-oxidant potential, while compounds 5c and 5g were found inactive. Conclusion: Schiff’s base (4a-4g) and substituted 1,3,4-oxadiazole (5a-5g) derivatives based on 4- fluorobenzoic acid scaffolds were synthesized using standard pathways. All compounds were structurally characterized through EI-MS and 1H-NMR spectroscopy and evaluated for their in vitro DPPH free radical scavenging activity. In-vitro study reveals that the newly prepared derivatives of 4-fluorobenzoic acid have potent antioxidant potential. Whereas compound 5c and 5g were found inactive, this study has recognized a series of potential molecules as antioxidant agents and is useful in the field of medicinal chemistry.

Design, Synthesis and Anticancer Evaluation of New 1-allyl-4-oxo-6-(3,4,5- trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile Bearing Pyrazole Moieties.

pyrimidine and pyrazole have various biological and pharmaceutical applications such as antibacterial, antifungal, antileishmanial, anti-inflammatory, antitumor, and anti-cancer. In this search, the goal is to prepare pyrimidine-pyrazoles and study their anticancer activity. 1-allyl-4-oxo-6-(3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile bearing pyrazoles (4,6-8) have been synthesized. Firstly, the reaction of 1-allyl-2-(methylthio)-4-oxo-6- (3,4,5-trimethoxyphenyl)-1,4-dihydropyrimidine-5-carbonitrile (1) with chalcones 2a-b produced the intermediates 3a-b. The latter was reacted with hydrazine hydrate to give the targets 4a-b. On the other hand, hydrazinolysis of compound 1 yielded the hydrazino derivative 5 which upon reaction with chalcones 2c-i or 1,3-bicarbonyl compounds afforded the compounds 6-8. Finally, the new compounds were characterized by spectral data (IR, 1H NMR, 13C NMR) and elemental analysis. Moreover, they were evaluated for Panc-1, MCF-7, HT-29, A-549, and HPDE cell lines as anticancer activity. All the tested compounds 3,4,6-8 showed IC50 values > 50 μg/mL against the HPDE cell line. Compounds 6a and 6e exhibited potent anticancer activity where the IC50 values in the range of 1.7- 1.9, 1.4-182, 1.75-1.8, and 1.5-1.9 μg/mL against Panc-1, MCF-7, HT-29, and A-549 cell lines. New pyrimidine-pyrazole derivatives were simply synthesized, in addition, some of them showed potential anticancer activity.

Interfacial nanoarchitectonics of nickel phosphide supported on activated carbon for transfer hydrogenation of nitroarenes under mild conditions

Metal phosphides are promising catalysts for hydrogenation reactions due to their unique ability to generate active hydrogen species which are essential for desired reactions. In this work, the hydrogenation potential of nickel phosphide (Ni2P) is explored for the transfer hydrogenation of aromatic nitro compounds using hydrazine hydrate as hydrogen source. The Ni2P was supported on activated carbon (AC) to facilitate highly exposed active reaction sites. The as-synthesized Ni2P-AC catalyst showed excellent catalytic potential for the hydrogenation of nitro compounds to corresponding amines with 100% conversion efficiency and resulted in excellent yields. The reaction conditions were optimized by varying different reaction parameters, such as time, temperature, solvents, catalyst amount and hydrogen sources. The developed reaction protocol is highly selective for nitro compounds having reduction susceptible functional groups like -Cl, -Br, –CHO, etc. The structure–activity relationship of the Ni2P-AC was also examined which suggested that both acidic and basic sites present in Ni2P-AC catalyst plays crucial role in hydrogenation reaction. Besides, an in-depth insight into the reaction mechanism illustrates that the reaction proceeds via N-phenyl hydroxylamine as the reaction intermediate. In addition, decent recyclability and stability of Ni2P-AC catalyst demonstrates its highly versatile nature for potential large-scale applications. The use of highly efficient Ni2P-AC catalyst for hydrogenation reactions can lead the way towards sustainable and effective industrial organic catalysis.

Morphology modulation and surface reconstruction of the NiFeSe arrays during long-term OER process at large current densities

Developing catalysts with long term stability at large current densities for oxygen evolution reaction (OER) remains a major challenge. Herein, the NiFeSe arrays were synthesized on the commercial nickel-iron foams (NFF) substrate using a one-step hydrothermal method by changing the hydrazine hydrate to solvent volume ratio in the precursors and reaction temperature. The NiFeSe/NFF catalyst prepared at the hydrazine hydrate to solvent volume ratio of 1:4 and reaction temperature of 160 °C shows the optimal OER electrocatalytic performance with a low overpotential of 245, 259 and 269 mV at the current density of 100, 200 and 300 mA cm−2, small Tafel slope of 44.7 mVdec−1 and large electrochemical surface area (ECSA) of 600 cm2 in 1 M KOH solution. Importantly, the OER activities of the NiFeSe/NFF catalyst exhibit enhancement during long-term stability test at a bias of 1.04 V (vs. Hg/HgO) for 327 h. During long-term continuous OER electrochemical process, the formation of NiFeOOH/NiFeSe heterojunction resulting from the surface reconstruction are responsible for enhancing OER activities by modulating the electron structure of interface and increasing the adsorption ability of intermediate *OH and *OOH on the surface of NiFeOOH. Our work provides new idea to design and construct heterostucture catalyst via the in-situ surface reconstruction.

Morphology and Phase Compositions of FePt and CoPt Nanoparticles Enriched with Noble Metal

The article reveals for the first time the features of nanoparticle morphology, phase compositions, and their changes when heating FePt and CoPt nanoalloys. Nanoparticles were obtained by co-reduction of precursor solution mixtures with hydrazine hydrate. The features were found by a complex of methods of X-ray diffraction (in situ XRD and X-ray scattering), TEM HR, and cyclic voltammetry. In addition, adsorbometry results were obtained, and the stability of different nanocluster structures was calculated by the molecular dynamics method. There were only FCC solid solutions in the X-ray patterns of the FePt and CoPt nanoalloys. According to XRD, in the case of nanoparticle synthesis with Fe and Co content less than 10 at. %, the composition of solid solutions was close to or practically equal to the composition of the as-synthesized nanoparticles quantified by inductively coupled plasma optical emission spectrometry. For systems synthesis with Fe and Co content greater than the above, the solubility limits (SLs) of Fe and Co in Pt were set 11.4 ± 0.7 at. % and 17.5 ± 0.6 at. %, respectively. Therefore, there were non-registered XRD extra-phases (XRNDPh-1) in the systems when CFe,Co ≥ SL. This statement was supported by the results of TEM HR and X-ray scattering: the smallest nanocrystals (1–2 nm) and amorphous particles were found, which qualitatively agreed with the sorbometry and SAXS results. Molecular dynamics calculations of stability for FePt and CoPt alloys claimed the structures of the most stable phase corresponded to phase diagrams (A1 and L12). Specific peculiarities of the morphology and compositions of the solid solutions of nanoalloys were established: structural blockiness (domain) and composition heterogeneity, namely, platinum enrichment of internal (deep) layers and homogenization of the nanoalloy compositions at relatively low temperatures (130–200 °C). The suggested model of the formation of nanoalloys during the synthesis, qualitatively, was compliant with the results of electrochemical deposition of FePt films on the surface of various electrodes. When nanocrystals of solid solutions (C(Fe, Co) &lt; SL) were heated above specific temperatures, there were phase transformations with the formation of two-phase regions, with solid solutions enriched with platinum or iron (non-registered XRD phase XRNDPh-2). The newly formed phase was most likely intermetallic compounds, FePt3, CoPt3. As a result of the study, the model was developed, taking into account the nanoscale of the particles: XRDPh (A1, FeaPt1−a) → XRDPh (A1, Fem×a−xPtm−m×a+x) + XRNDPh-2 (Fen×a+yPtn−n×a−y) (here, m + n = 1, m ≤ 1, n ≤ 1).

Carbon-supported Pd/NiO-CoOx nanoparticles for highly selective and stable 1-nitroanthraquinone hydrogenation

1-aminoanthraquinone has numerous applications in chemical industry, for example, it is an important intermediate for producing anthraquinone dyes. In this work, Pd/NiO/C, Pd/CoOx/C, and Pd/NiO-CoOx/C (C-carbon black) are prepared by room-temperature hydrazine hydrate and replacement reduction methods. All as-prepared catalysts have been characterized by XRD, SEM, TEM, HRTEM, XPS, STEM-EDX elemental mapping and line-scanning et al., The Pd-related species are highly dispersed on the nickel, cobalt or nickel-cobalt oxide nanoparticles (NPs), the interaction of Pd–NiO (or CoOx, NiO-CoOx) is present. Pd/NiO-CoOx/C provides 99.2 % conversion of 1-nitroanthraquinone and 91.0 % selectivity to 1-aminoanthraquinone for 1-nitroanthraquinone hydrogenation under the following reaction conditions: H2 pressure-3.0 MPa, 60 °C, 4 h. The catalytic behaviors of Pd/NiO-CoOx/C for 1-nitroanthraquinone hydrogenation are much better than Pd/NiO/C and Pd/CoOx/C mainly due to the interaction of Pd–NiO-CoOx, synergy effect of Pd and NiO-CoOx, and high Pd dispersion.

Hydrazine Sulfonic Acid, NH3 NH(SO3 ), the Bigger Sibling of Sulfamic Acid.

The reaction of hydrazine hydrate, N2 H4 ⋅ H2 O, and SO3 leads to hydrazine sulfonic acid (Pca21 , a=849.59(4) pm, b=482.18(2) pm, c=832.17(4) pm). Structure elucidation reveals the zwitter-anionic nature of the compound according to NH3 NH(SO3 ). With the barium salt Ba[NH2 NH(SO3 )]2 (H2 O), a first salt of hydrazine sulfonic acid has been prepared (P , a=489.75(5) pm, b=737.52(7) pm, c=1317.4(1) pm, α=88.238(4)°, β=84.761(4)°, γ=79.701(4)°). The compounds were characterized by vibrational spectroscopy, DFT calculations and thermal analyses.

Синтез и антибактериальная активность производных 3-аллил-5,5-диметил-2-тиоксо-2,3,5,6-тетрагидробензо[h]хиназолин-4(1H)-она

Alkylation of 3-allyl-5,5-dimethyl-2-thioxo-2,3,5,6-tetrahyd-robenzo[h]quinazo-line-4(1H)-one (thioxobenzoquinazoline) was alkylated in an alkaline medium with halides of various structures, resulting in the formation of 2-sulfanylsubstituted 3-allyl-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin-4(3H)-ones. The condensation of thioxobenzohquinazoline with hydrazine hydrate yielded 3-allyl-2-hydrazinyl-5,5-dimethyl-5,6-dihydroben-zo[h]quinazoline-4(3H)-one. However, analogous reactions with 2-ethanolamine and 3-propanolamine proceeded anomalously, resulting in the formation of 2-(2-hydroxyethyl)amino-5,5-dimethyl-5,6-dihydroben-zo[h]quinazoline-4(3H)-one and 2-(3-hydroxypropyl)amino-5,5-dimethyl-5,6-dihydro-benzo[h]quinazoline-4(3H)-one, respectively. Interaction of the mentioned thioxoben-zohquinazoline with benzylamine occurs through intramolecular cyclization, forming 6,6,10-trimethyl-9,10-dihydro-5H-benzo[h]thiazolo[2,3-b]quinazoline-7(6H)-one. The antibacterial properties of the synthesized compounds were studied against both Gram-positive and Gram-negative microorganisms. The research results revealed that the investigated compounds possess antibacterial activity.

Crosslinking through acyl hydrazone formation by reacting water soluble polyurethanes derived from ketone diol comonomers and those containing hydrazide pendant groups

Fully water-based formulations are gaining traction with the sustainability initiative for various applications. In this regard, producing the components required for making these formulations by eliminating toxic reagents is highly desirable. Hydrazone formation is widely used as a non-hazardous curing process in coating applications. Generally, carbonyl compounds that are used in the hydrazone forming reaction are nearly exclusively derived from vinyl polymers. This article describes a facile process for making carbonyl group containing diols and keto group containing water-soluble polymers therefrom by step growth or condensation polymerization. A water-soluble polymeric hydrazide was prepared by DCC coupling reaction between hydrazine hydrate and a polyurethane bearing pendant carboxylic acid group. The aqueous solutions of keto group containing, and hydrazide pendant polymers were mixed and coated on glass slides. Subsequently, the acyl hydrazone formation was studied under static heating in a hot air oven and a dynamic condition provided by blowing air under ambient conditions with a hair dryer. The dynamic nature of the latter process more than compensated the absence of direct heating to induce drying and hydrazone formation sequentially as studied by FT-IR spectroscopy. The cured slides were stable to water and were sensitive to weakly acidic aqueous solutions (about pH 3) formed by dissolving citric acid in water. The keto group containing diols enabled the hydrazone formation in polymer pairs entirely derived from step growth polymerization. As step growth or condensation polymers potentially offer both degradability and recycling through the cleavage of labile bonds prevailing in the polymer backbone, these keto group containing diols are preferable alternatives to keto group containing vinyl monomers commonly used for making hydrazones.