Ammonium Thiocyanate Research Articles

New quinazolin-2,4-dione derivatives incorporating acylthiourea, pyrazole and/or oxazole moieties as antibacterial agents via DNA gyrase inhibition.

This article contributes to the search for new therapeutic agents for treatment of diseases caused by bacterial pathogens. In this study, a new series of compounds incorporating numerous bioactive moieties such as quinazolin-2,4-dione, acylthiourea linkage, and/or five membered nitrogen heterocycles (pyrazole and oxazole) 2-5a-c was described to identify new antibacterial drug candidates via inhibition of DNA gyrase enzyme. The precursor N-[N'-(2-cyano-acetyl)-hydrazinocarbothioyl]-4-(2,4-dioxo-1,4-dihydro-2H-quinazolin-3-yl)-benzamide 2 was prepared by treatment of compound 1 with ammonium thiocyanate and cyanoacetic acid hydrazide through multicomponent reaction (MCR). In addition, compounds 3a-d and 4a-b were synthesized by treatment of 2 with aromatic aldehydes and/or ketones through Knoevenagel reaction, affording high purity products in satisfactory yields. Moreover, new heterocyclic moieties such as pyrazole and/or oxazole attached to quinazolin-2,4-dione core 5a-c were synthesized by treatment of 3c with different nucleophilic reagents like hydrazine, phenyl hydrazine and hydroxyl amine, respectively. Subsequently, the obtained products were structurally characterized by IR, 1H-, 13C-NMR, and MS analyses. The minimum inhibitory concentration (MIC) and antibacterial potency of all compounds were estimated against two G-ve (E. coli and P. aeruginosa), and two G+ve bacteria (B. subtilis and S. aureus). Encouragingly, compound 3c demonstrated the best antibacterial activity against all the strains of the tested pathogenic bacteria at low concentrations compared with the standard drug, Ciprofloxacin. Electron withdrawing groups such as -NO2 and -Cl enhance the antibacterial activity. Next, a molecular docking study between the synthesized derivatives and the target enzyme, DNA gyrase enzyme (PDB: 2xct) was undertaken to investigate intermolecular interactions between the compounds and target enzyme.

Copper-catalyzed thiocyanation of cyclobutanone oxime esters using ammonium thiocyanate.

A copper-catalyzed thiocyanation of cycloketone oxime esters with ammonium thiocyanate has been developed for the first time. This innovative approach allows access to cyano and thiocyano bifunctionally substituted alkanes, which can be further transformed into their respective trifluoromethylthiol-substituted or difluoromethylthiol-substituted alkylnitriles, alkynyl sulfides, and phosphorothioate esters. The readily available nature of ammonium thiocyanate and the cost-effectiveness of the copper catalyst make this method a promising strategy for the synthesis of sulfur-containing alkylnitriles.

Ammonium halide selective ion pair recognition and extraction with a chalcogen bonding heteroditopic receptor.

The first example of a heteroditopic receptor capable of cooperative recognition and extraction of ammonium salt (NH4X) ion-pairs is described. Consisting of a bidentate 3,5-bis-tellurotriazole chalcogen bond donor binding cleft, the appendage of benzo-15-crown-5 (B15C5) substituents to the tellurium centres facilitates binding of the ammonium cation via a co-facial bis-B15C5 sandwich complex, which serves to switch on chalcogen bonding-mediated anion binding potency. Extensive quantitative ion-pair recognition 1H NMR titration studies in CD3CN/CDCl3 (1 : 1, v/v) solvent media reveal impressive ion-pair binding affinities towards a variety of ammonium halide, nitrate and thiocyanate salts, with the heteroditopic receptor displaying notable ammonium halide salt selectivity. The prodigious solution phase NH4X recognition also translates to efficient solid-liquid and liquid-liquid extraction capabilities.

Synthesis, photophysical properties, anticancer evaluation, and molecular docking studies of new pyrimidine linked 4-arylidene-thiazolidin-4-ones as potent anticancer agents.

The reaction of 4-(chloroacetamido)pyrimidine (1) with ammonium thiocyanate gave 2-(pyrimidin-4-ylimino)thiazolidin-4-one (2), which, when condensed with four substituted benzaldehyde analogues, gave the consequent 5-arylidine-2-(pyrimidin-4-ylimino)thiazolidin-4-ones 3a-d. In addition, the absorbance and fluorescence behaviours of pyrimidinylimino-thiazolidin-4-one hybrids 3a-d in various organic solvents were investigated. The emphasis was on studying UV absorption capacities and the effect of various structural components on photophysical qualities such as the 5-arylidene-2-(pyrimidin-4-ylimino)thiazolidin-4-ones and N,N-dimethylamino tail. The cytotoxic effect of four pyrimidinylimino-thiazolidin-4-one hybrids 3a-d on tumour cell lines (HepG2, HCT-116, PC3, MCF-7) and a normal cell line (WI38) is investigated in this work. The cytotoxicity was measured by comparing the half-maximal inhibitory concentration (IC50 ) to the reference medication, 5-fluorouracil. The findings indicate that these hybrid compounds had varying cytotoxic effects on the cell lines examined; hybrids 3b and 3c demonstrated significant anticancer activity against MCF-7 with IC50 values of 7.53 ±0.43 and 9.17 ±0.31 μM, respectively. The inhibitory efficacy of various synthesized hybrids on the epidermal growth factor receptor (EGFR) kinase was investigated. EGFR is a crucial target in cancer treatment because inhibiting it may reduce tumour development and proliferation. The IC50 value was used to calculate the inhibitory activity, which is the concentration of inhibitor necessary to induce half-maximal inhibition of EGFR kinase activity. In addition, the predicted ADME results show that pyrimidinylimino-thiazolidin-4-one hybrids have good pharmacokinetic properties; hybrid 3d is more lipophilic than the other compounds. It has a medium molecular weight, a small number of hydrogen bond acceptors and donors, and a large number of aromatic heavy atoms. Moreover, molecular docking simulations revealed precise information on the interactions of pyrimidinylimino-thiazolidin-4-one hybrids 3a-d and 5-Fu with their respective protein targets. These interactions point to possible pathways for their biological activities and call for more testing to establish their effectiveness as bioactive molecules or therapeutic candidates.

Copper-catalyzed ortho-thiocyanation of aromatic amines.

A copper-catalyzed direct ortho-Csp2-H thiocyanation of free anilines has been developed. This method employs stable and non-toxic ammonium thiocyanate as a thiocyanation source, and tert-butyl hydroperoxide as the oxidant, enabling the synthesis of ortho-thiocyanated anilines with good yields and broad substrate tolerance. Hitherto, no reports have been found in the literature for the ortho-thiocyanation of aromatic amines, making this reaction an important breakthrough in synthetic organic chemistry.

SYNTHESIS OF 2-FLUOROBENZOYL THIOUREA DERIVATIVES

Fluorine-containing compounds play a significant role in drug development because fluorine atom has unique chemical properties due to its high electronegativity which significantly influences the properties important for drug design. In the present study, 2-fluorobenzoyl thiourea derivatives were synthesized by the reaction of 2-fluorobenzoyl isothiocyanate, which was obtained by the reaction of 2-fluorobenzoyl chloride with ammonium thiocyanate, with appropriate aniline derivatives. The structures of the benzoyl thioureas were confirmed by IR, 1H and 13C NMR spectroscopy.

Synthesis and Characterization of Multicolor Luminescent and Thermally Stable Thioureas and Polythioamides.

Two new polythioamides were prepared through the polycondensation reaction between thiourea monomers and terephthaloyl dichloride, while the thiourea monomers were synthesized by the interaction of aromatic (4,4'-diaminophenylsulfone) or alicyclic (1,2-cyclohexanediamine) diamine with ammonium thiocyanate. The elemental composition of polythioamides was confirmed through CHN microanalysis. The structure and properties of thiourea monomers and polythioamides were determined through proton NMR, UV-Vis, FT-IR spectroscopy, fluorescence, TGA/DTA and SEM. The polythioamides indicated high thermal stabilities which were assessed from their Tmax (temperature indicating highest rate of weight loss) values (670 °C and 346 °C) observed in their DTG graphs. The thioureas and polythioamides were fluorescent and showed multicolor (violet, green, yellow, orange and red) emissions at different excitation wavelengths. All the synthesized compounds were also tested for their antifungal and antibacterial functions and showed antibacterial activity against Salmonella typhi, Bacillus subtilis and Staphylococcus aureus, and antifungal activity against Candida albicans.

Local atomic structures and lattice dynamics of inverse colossal barocaloric ammonium thiocyanate

Local atomic structures and lattice dynamics of inverse colossal barocaloric ammonium thiocyanate

Supporting Electrolyte-Free Electrochemical Oxidative C-H Sulfonylation and Thiocyanation of Fused Pyrimidin-4-Ones in an All-Green Electrolytic System.

An electrooxidative C-H functionalization is a widely accepted route to obtain sulfur-containing arenes and heteroarenes. However, this process often involves using non-recyclable supporting electrolytes, (co)solvents like hexafluoroisopropanol, additives like acid, or catalysts. The use of additional reagents can increase costs and waste, reducing atom efficiency. Moreover, unlike other nitrogen-containing heterocycles, there have only been sporadic reports of electrochemical C-H functionalization in fused pyrimidin-4-ones, and an electrolyte-free process has yet to be developed. This work demonstrates that such anodic coupling reactions can be performed in an all-green electrolytic system without using such additional electrolytes or HFIP, maintaining a high atom economy. This C-H functionalization strategy utilizes inexpensive sodium sulfinates and ammonium thiocyanate as sulfonylating and thiocyanating agents in an undivided cell at a constant current, using a mixture of CH3 CN/H2 O as solvent at room temperature. Thus, fused pyrimidin-4-ones can be selectively converted into C3-sulfonylated and -thiocyanated derivatives in moderate to good yields.

Synthesis of Some Benzothiazole Derivatives Based on 3-hydroxypyridine-4-one and Benzaldehydeand Evaluation of their β-amyloid Aggregation Inhibition using both Experimental Methods and Molecular Dynamic Simulation.

Some novel inhibitors based on the (benzo[d]thiazol-2-yl)-1-phenylmethanimine derivatives were designed to reduce the aggregation process in Alzheimer's disease. These structures seem to mimic stilbene-like scaffold, while the benzothiazole moiety "locks" the thioflavin T binding site. Other inhibitors were designed based on 2-((benzo[d]thiazol-2-ylimino)methyl)-5-(benzyloxy)-1-methylpyridin-4(H)-one derivatives. Benzo[d]thiazol-2-amine derivatives were prepared by the reaction of aniline derivatives with ammonium thiocyanate in the presence of bromine/acetic acid. Then, the reaction of amines with benzaldehyde derivatives and 5-(benzyloxy)-1-methyl-4-oxo-1,4-dihydropyridine-2-carbaldehyde gave the desired compounds. The plate reader-based fibrillation assay was done to evaluate the inhibition of Aβ aggregation. Also, molecular dynamicsimulation was carried out to clarify the interaction manner of the designed compounds with Aβ formation. The biological evaluation proved 5a and 7e as the best inhibitor of the Aβ aggregation. compound 5a in concentration of 50 µM inhibited Aβ fibril formation better than 7e. MD simulation elucidated that the Aβ aggregation inhibitors in different concentrations represented different binding conformations throughout the entire or in one area of Aβ. MD showed the ligands in lower concentrations accumulate in an area of Aβ aggregations and separate one fibril from the aggregated Aβ. On the contrary, in higher concentrations, the ligands tend to be located through the entire Aβ.

Ambient-Stable 2D Dion-Jacobson Phase Tin Halide Perovskite Field-Effect Transistors with Mobility Over 1.6 Cm2 V-1 S-1.

Solution-processed metal halide perovskites hold immense potential for the advancement of next-generation field-effect transistors (FETs). However, the instability of perovskite-based transistors has impeded their progress and practical applications. Here we report ambient-stable high-performance FETs based on two-dimensional Dion-Jacobson phase tin halide perovskite BDASnI4 that has high film quality and excellent electrical properties. The perovskite channels are established by engineering the film crystallization process via the employment of ammonium salt interlayers and the incorporation of NH4 SCN additives within the precursor solution. The refined FETs demonstrate field-effect hole mobilities up to 1.61 cm2 V- 1 s- 1 and an on/off ratio surpassing 106 . Moreover, the devices show impressive operational and environmental stability, and retain their functional performance even after being exposed to ambient conditions with temperature of 45°C and humidity of 45% for over 150 hours. This article is protected by copyright. All rights reserved.

Addition of Ammonium Thiocyanate Alters the Microstructure and Energetic Landscape of 2D/3D Perovskite Films

Addition of Ammonium Thiocyanate Alters the Microstructure and Energetic Landscape of 2D/3D Perovskite Films

Impurity doping effects and ecological friendly synthesis of cerium sulfide powders for enhanced chromaticity and color tunability

Red non-toxic and environmentally friendly γ-phase cerium sulfide powders have promising applications in the fields of coatings, outdoor displays and smart buildings. However, the development of an environmentally friendly preparation process and the improvement of production efficiency of cerium sulfide powders remain major challenges. In this study, eco-friendly γ-Ce2S3 powders with excellent color properties have been produced by adding ammonium thiocyanate to the precursor of cerium without H2S or CS2. The effect of impurities (mainly Ce2O2S) with different amounts on spectral properties of cerium sulfide powders has been studied through chemical and physical methods. In addition, the significance of impurity doping on the reaction synthesis was studied by combining detailed experimental characteristics with density functional theory calculations. The results show that the reduction of impurity content can greatly improve the chromaticity value of γ-Ce2S3 and change color from dark red to bright red.

Phytochemical Profile, Antioxidant Activity and Cholinesterase Inhibition Potential of Essential Oil and Extracts of Teucrium montanum from Bosnia and Herzegovina

Bioactive compounds from plants play an important role in slowing many neurodegenerative diseases, such as Alzheimer’s disease, by inhibiting cholinesterase enzymes. Studies have shown that oxidative stress is associated with the development of Alzheimer’s disease. In traditional medicine of Bosnia and Herzegovina, Teucrium montanum is used to treat numerous diseases. The chemical composition and biological activity of the essential oil (EO) and aqueous (AE) and methanol extract (ME) of this plant were studied. The chemical composition of EO was studied using GC-MS, while the composition of the extracts was studied using HPLC-DAD. Antioxidant activity was tested using the DPPH and FRAP methods. The protection of lipids and proteins from oxidation was tested using the ammonium thiocyanate and BSA oxidation methods. The ability to inhibit cholinesterases was tested by the Ellman method. The main identified EO compounds were α-cadinol, ß-selinene, δ-cadinene, epi-α-cadinol, germacrene D-4-ol, and α-pinene. The main phenolic compounds of the extracts were p-coumaric acid, ellagic acid and caffeic acid. The tested extracts showed good antioxidant radical scavenging and reducing potential and a very good ability to protect lipids and proteins from oxidation. The EO showed moderate AChE and BChE inhibition potential, while the extracts showed weak or no ability.

Design, synthesis, molecular docking, and dynamic studies of novel thiazole derivatives incorporating benzimidazole moiety and assessment as antibacterial agents.

A general and sustainable approach for the synthesis of benzimidazole-thiazole compounds via an efficient, one-pot, domino, pseudo-four-component reaction using 5-amino-2-mercaptobenzimidazole, aralkyl halides, ammonium thiocyanate, and substituted α-bromo-acetophenones in glacial acetic acid at ambient temperature to give final compounds (4a-p) in good yields in shorter time. The spectral data of synthesized compounds were evaluated by analytical and spectral techniques (IR, 1H-NMR, 13C-NMR, and ESI-HRMS). Further, some of the synthesized compounds were screened for their in-vitro antibacterial activity studies using the agar well diffusion method against Gram-positive Streptococcus pneumoniae (2451) bacteria and Gram-negative Proteous mirabilis (2081) bacteria. Based on the MIC results, it was observed that the most active compounds 4b, 4e, 4f, and 4k show promising antibacterial activity with the zone of inhibition values of 2.85cm 2.75cm, 3.6cm, and 3.3cm against both Gram-negative and positive bacteria cell lines, respectively. Further, we have also insight into the molecular simulation studies, based on the binding results, compound 4i showed stable binding interactions with streptomycin drug with the active site of the gyrase protein (PDB ID: 1KIJ). The structure-activity relationship (SAR) studies of all the title scaffolds were also established. The antibacterial activity, molecular docking studies, and molecular dynamic simulations of the title compounds suggested that these are promising antibacterial active skeletons.

Effect of sodium ions doping on structure and spectral properties of γ-Ce2S3 microcrystals

Rare earth sulfides are environmentally friendly and have excellent physical optoelectronic properties and coloring applications. In particular, red γ-Ce2S3 is an important and popular inorganic optical functional material. However, it has become crucial to improve the production efficiency of γ-Ce2S3 and its color performance and stability. By adding ammonium thiocyanate to the precursor, eco-friendly γ-Ce2S3 with excellent color performance was produced in this study. In addition, the effect of different amounts of Na+ doping on the final product's purity and the effect of chroma value were systematically investigated. Results show that an increase in Na+ can effectively lower the synthesis temperature of γ-Ce2S3, improve production efficiency, and optimize color performance prior to saturation. Finally, using density functional theory, the influence of the vacancy structure of γ-Ce2S3 and the change of energy band after the addition of Na+ were calculated, and a detailed experimental characterization in conjunction with density functional theory calculation thoroughly explained the significance of ion doping for reaction synthesis.

A mononuclear N,N,N,O donor schiff base Cu(II) complex inhibits bacterial biofilm formation and promotes apoptosis and cell cycle arrest in prostate cancer cells

In this work, we report a distorted square pyramidal mononuclear copper(II) complex [Cu(L)(NCS)] (1) which was obtained by the reaction of the aqueous solution of ammonium thiocyanate to a methanolic solution of copper nitrate trihydrate and corresponding Schiff-base ligands. Schiff bases, HL (C12H19N3O) act as a tetradentate Schiff base, derived from 1:1 condensation of o-hydroxyacetophenone and diethylenetriamine. The synthesized complex has been successfully characterized based on elemental analysis and Infrared (IR) spectroscopy. The structure of complex 1 was confirmed by single-crystal X-ray diffraction study. In our study, we investigated synthesis, structural characterization, antimicrobial, anti-biofilm, and anti-cancer activity, and plausible mechanism of action of a novel mononuclear copper(II) schiff base complex. Increasing microbial resistance to several commercially available or traditional antimicrobial compounds has become a major global health concern at present time. The mononuclear copper(II) complex exhibited potential antibacterial activity against two strains of the gram-negative pathogen Pseudomonas aeruginosa. The copper compound dependent damage of bacterial cell membrane and inhibition of bacterial biofilm formation were also identified. Moreover, complex 1 inhibited prostate cancer cell growth, and migration by inducing apoptosis and arresting the cell cycle at the G2/M phase. Based on the results, we are suggesting our novel mononuclear copper(II) compound as a potential candidate for the development of new antibacterial and anti-cancer drugs.

Visible light-induced thiocyanation of gem-difluorinated phosphonium salts

gem-Difluorinated phosphonium salts were generated from nitrones by methylation and reaction with (triphenylphosphonio)difluoroacetate. The phosphonium salts were subjected to visible light-induced phosphonium–thiocyanate exchange in the presence of ammonium thiocyanate, copper thiocyanate, and an iridium photocatalyst. The sequence of the reactions was performed in one pot affording thiocyanates attached to the difluoromethylene fragment.

Molecular geometry and biological activity of 2-(4-substituted-phenylimino)thiazolidin- 4-one compounds

ABSTRACT. A series of 2-(4-substituted-phenylimino)thiazolidin-4-one compounds was synthesized via heterocyclizing the corresponding N-aryl-2-chloroacetamides with ammonium thiocyanate. Their chemical structures were elucidated based on an extensive analysis of their spectroscopic data, including infrared, 1H NMR, 13C NMR, and mass analyses. The possible tautomeric forms of synthesized thiazolidine-4-ones were studied. The tautomerization equilibrium parameters, ΔH, ΔG, and Keq were calculated using the DFT/B3LYP methodology, where it has been indicated that the tautomeric form, phenylimino, is more favourable than the phenylamino form. The antibacterial and antioxidant properties of the synthesized thiazolidin-4-ones were investigated. 2-(Chlorophenyl-imino)thiazolidin-4-one displayed potent antibacterial activity against E. coli (88.46%) and S. aureus (91.66%), and highest percent of inhibition (81.8%, ABTS assay).
 
 KEY WORDS: N-aryl-2-chloroacetamides, Ammonium thiocyanate, 2-(Arylimino)thiazolidin-4-ones, Mulliken’s charges, Dipole moment, ABTS assay
 Bull. Chem. Soc. Ethiop. 2023, 37(5), 1275-1286. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i5.18

A Refractive Index- and Density-Matched Liquid–Liquid System Developed Using a Novel Design of Experiments

Refractive index and density matching are essential for optical measurements of neutrally buoyant liquid–liquid flows. In this study, we proposed a design of experiments (DoE) to develop refractive index and density matching systems, including objective setting, candidates screening, sampling and fitting, and a detailed matching process. Candidates screening criteria based on the density and refractive index ranges of the aqueous and organic phases were used. Using the DoE, we proposed a system with a ternary aqueous phase potassium thiocyanate (KSCN)/ammonium thiocyanate (NH4SCN) solution and m-dichlorobenzene/tripropionin solution as the organic phase to achieve the tuning of the RI and density simultaneously. Empirical correlations of the refractive index and density with respect to the concentration and temperature for the three mixtures were obtained by combining Latin hypercube sampling with binary polynomial fitting. Correlations were validated with existing data in the literature and were found to align with deviations as low as 4×10−4 for the refractive index and 2×10−3 g⋅cm−3 for the density. Using the correlations, the refractive indices for the ternary aqueous phase, the binary organic phase, and the device materials were matched to be equal. Density matching was performed for the liquid–liquid phases as well. Refractive index- and density-matched recipes could be obtained for a wide range of temperatures (15–65 °C) and device materials (PMMA, borosilicate glass, quartz, and silica gel). These recipes provide options for the optical measurement of a liquid–liquid system required to neutralize buoyancy.