Search Results (28)

Synthesis of 6-(5-mercapto-4R-4H-1,2,4-triazol-3-yl)pyrimidine-2,4(1H,3H)-dione derivatives offer a versatile platform for the development of new heterocyclic compounds. These molecules combine the biologically relevant 1,2,4-triazole ring, known for its antimicrobial and antioxidant properties, with a pyrimidine-2,4-dione core structurally related to vitamin B₁₃ (orotic acid), essential in nucleic acid metabolism. This dual structure opens a wide spectrum of synthetic possibilities, particularly in heterocyclization reactions. The synthesis usually begins with the formation of the triazole ring through cyclocondensation of thiosemicarbazides with appropriate carbonyl precursors, followed by functionalization of the thiol group via S-alkylation or S-arylation. Full article

Thiosemicarbazones (TSCs) with their modular character (thiosemicarbazides + carbonyl compound) allow broad variation of up to four substituents on the main R¹R²C=N(1)–NH–C(S)–N(4)R³R⁴ core and are thus interesting tools for the formation of conjugates or the functionalization of nanoparticles (NPs). In this work, di-2-pyridyl ketone was introduced for the coordination of metals and 9-anthraldehyde for luminescence as R¹ and R² to TSCs. R³ and R⁴ substituents were varied for the formation of conjugates. Amino acids were introduced at the N4 position to produce [R¹R²TSC–spacer–amino acid] conjugates. Further, functions such as phosphonic acid (R–P(O)(OH)₂), D-glucose, o-hydroquinone, OH, and thiol (SH) were introduced at the N4 position producing [R¹R²TSC–spacer–anchor group] conjugates for direct NP anchoring. Phenyl, cyclohexyl, benzyl, ethyl and methyl were used as spacer units. Both phenyl phosphonic acid TSC derivatives were bound on TiO₂ NPs as a first example of direct NP anchoring. [R¹R²TSC–spacer–end group] conjugates including OH, S–Bn (Bn = benzyl), NH–Boc (Boc = tert-butyloxycarbonyl), COOtBu, C≡CH, or N₃ end groups were synthesized for potential covalent binding to functional molecules or functionalized NPs through amide, ester, or triazole functions. The synthesis of the thiosemicarbazides H₂NNH–C(S)–NR₃R₄ starting from amines, including amino acids, SCCl₂ or CS₂, and hydrazine and their condensation with dipyridyl ketone and anthraldehyde led to 34 new TSC derivatives. They were synthesized in up to six steps with overall yields ranging from 10 to 85% and were characterized by a combination of nuclear magnetic resonance spectroscopy and mass spectrometry. UV-vis absorption and photoluminescence spectroscopy allowed us to easily trace the dipyridyl imine and anthracene chromophores. Full article

A new silver(I) cluster [Ag₈L₄(Py)(Pype)]·4Py·11H₂O (I) with 3-benzyl-4-phenyl-1,2,4-triazol-5-thiol (L) was synthesized via the direct reaction of AgNO₃ and L in MeOH, followed by recrystallization from a pyridine–piperidine mixture. The compound I was isolated in a monocrystal form and its crystal structure was determined via single crystal X-ray diffraction. The complex forms a “butterfly” cluster with triazol-5-thioles. The purity of the silver complex and its stability in the solution was confirmed via NMR analysis. Excitation and emission of the free ligand and its silver complex were studied at room temperature for solid samples. The in vitro biological activity of the free ligand and its complex was studied in relation to the non-pathogenic Mycolicibacterium smegmatis strain. Complexation of the free ligand with silver increases the biological activity of the former by almost twenty times. For the newly obtained silver cluster, a bactericidal effect was established. Full article

The reaction of 2-bromo-1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (1) with 4-amino-5-((2,4-dichlorophenoxy)methyl)-4H-1,2,4-triazole-3-thiol (2) in absolute ethanol in the presence of triethyl amine as catalyst gave 2-((4-amino-5-((2,4-dichlorophenoxy)methyl)-4H-1,2,4-triazol-3-yl)thio)-1-(5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)ethan-1-one (3) in 73% yield. The structure of the title heterocycle (3) was confirmed by X-ray single crystal diffraction and spectral analyses (NMR and IR). Full article

The scope of the current work was to synthesize an S-alkylated 1,2,4-triazole-3-thiol derivative. Synthesis was carried out in two steps: in the first step, 4,5-diphenyl-4H-1,2,4-triazole-3-thiol was S-alkylated using a halogenated acetal and cesium carbonate. In the second step, several acetal deprotection procedures were tested, and the aldehyde obtained was isolated as a bisulfite adduct. The structures of the new compounds were characterized by FT-IR, 1D, and 2D NMR spectroscopic methods. Full article

Nuclear factor kappa beta (NF-κB) is a transcriptional factor that plays a crucial role in regulating cancer cell proliferation. Therefore, the inhibition of NF-κB activity by small molecules may be beneficial in cancer therapy. In this report, methyl-thiol-bridged oxadiazole and triazole heterocycles were synthesized via click chemistry and it was observed that the lead structure, 2-(((1-(3,4-dichlorophenyl)-1H-1,2,3-triazol-4-yl)methyl)thio)-5-(4-methoxybenzyl)-1,3,4-oxadiazole (4c), reduced the viability of MCF-7 cells with an IC₅₀ value of 7.4 µM. Compound 4c also caused concentration-dependent loss of cell viability in chronic myelogenous leukemia (CML) cells. Furthermore, compound 4c inhibited the activation of NF-κB in human CML cells as observed by nuclear translocation and DNA binding assays. Functionally, compound 4c produced PARP cleavage and also suppressed expression of Bcl-2/xl, MMP-9, COX-2, survivin, as well as VEGF, resulting in apoptosis of CML cells. Moreover, ChIP assay showed that compound 4c decreased the binding of COX-2 to the p65 gene promoter. Detailed in silico analysis also indicated that compound 4c targeted NF-κB in CML cells. In conclusion, a novel structure bearing both triazole and oxadiazole moieties has been identified that can target NF-κB in CML cells and may constitute a potential novel drug candidate. Full article

In a basic medium, 5-Mercapto-1,2,4-triazoles pass into the thiol form, allowing their transformation into sodium salts, which, in reaction with sodium monochloroacetate, lead to sodium 5-thioacetates of 1,2,4-triazoles-3,4-disubstituted. Sulfur derivatives converted to pivalic mixed anhydrides were used as active forms in the acylation of 6-amino penicillanic acid (6-AP) to obtain new semisynthetic penicillins. They contain in the molecule, together with the β-lactam ring, the nucleus 3-[(5-nitroindazol-1′-yl-methyl)]-4-aryl-5-mercapto-1,2,4-triazole, both contributing to an important antibacterial effect. The structure of the new antibiotics was confirmed by the results of elemental and spectral analysis (FT-IR, ¹H- and ¹³C-NMR). The synthetic penicillins were tested for toxicological action and antibacterial activity and the obtained results were close to those for amoxicillin, the reference drug. Full article

A novel approach was carried to prepare trans-CuCl₂L₂ complex with the ligand L, (E)-(4-chlorophenyl)-N-(3-phenyl-4H-1,2,4-triazol-4-yl)methanimine which was formed in situ during the reaction of CuCl₂ with 4-(4-chlorobenzylideneamino)-5-phenyl-2H-1,2,4-triazole-3(4H)-thione. The synthesized compounds were characterized by applying various spectroscopic techniques. The crystal structure of the complex was unambiguously determined using X-ray analysis indicating square planar geometry. Intermolecular H-bonds govern the supramolecular structure of the copper complex. Aromatic rings are stacked in an offset packing due to occurrence of π–π interactions. The structure is further corroborated with a detailed computational investigation. A thione–thiol tautomerism for the triazole compound was also studied. The Schiff base 1,2,4-triazole copper chloride complex is expected to have high anticancer activity. Full article

This study of the interaction system of binucleophilic 3-substituted 4-amino-4H-1,2,4-triazole-5-thiols and 3-phenyl-2-propynal made it possible to develop a new approach to synthesis of such isomeric classes as 7-benzylidene-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine and 8-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazepine. Among the 20 compounds studied in vitro against influenza A/Puerto Rico/8/34 (H1N1) virus, half of them demonstrated selectivity index (SI) of 10 or higher and one of them (4-((3-phenylprop-2-yn-1-yl)amino)-4H-1,2,4-triazole-3-thiol) possessed the highest (SI > 300). Docking results and values showed that the preferred interactant for our ligands was M2 proton channel of the influenza A virus. Protein-ligand interactions modeling showed that the aliphatic moiety of ligands could negatively regulate target activity level. Full article

Novel anthracene-based Schiff base derivative (4-(anthracen-9-ylmethylene) amino)-5-phenyl-4H-1,2,4-triazole-3-thiol; AT2) is synthesized and utilized as an aggregation-induced emission-enhancement (AIEE) active probe to detect Zn²⁺ and Tyrosine. Ultraviolet-visible absorption/photoluminescence (UV-vis/PL) spectroscopy studies on the AIEE property of AT2 (in ethanol) with increasing water fractions (f_w: 0–97.5%) confirm the J-type aggregation. Excellent sensor selectivity of AT2 to Zn²⁺ and its reversibility with Tyrosine are demonstrated with PL interrogations. 2:1 and 1:1 stoichiometry and binding sites of AT2-Zn²⁺ and Tyrosine-Zn²⁺ complexes are elucidated from Job plots, HR-mass, and ¹H-NMR results. Nanomolar-level detection limits (LODs) of Zn²⁺ (179 nM) and Tyrosine (667 nM) and association constants (K_as) of 2.28 × 10⁻⁶ M⁻² (for AT2-Zn²⁺) and 1.39 × 10⁻⁷ M⁻¹ (for Tyrosine-Zn²⁺) are determined from standard deviation and linear fittings. Nanofiber formation in AIEE and aggregated/dispersed nanoparticles in the presence of the Zn²⁺/Tyrosine are supported by scanning-electron microscope (SEM), transmission-electron microscope (TEM), atomic-force microscope (AFM), and dynamic-light scattering (DLS) investigations. Density-functional theory (DFT) studies confirm an “On-Off” twisted intramolecular charge transfer/photo-induced electron transfer (TICT/PET) and “On-Off-On” PET mechanisms for AIEE and sensors, respectively. B16-F10 cellular and zebrafish imaging are conducted to support the applications of AIEE and sensors. Full article

A series of 3-(6-substituted phenyl-[1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazol-3-yl)-1H-indoles (5a–l) were designed, synthesized and evaluated for anti-apoptotic Bcl-2-inhibitory activity. Synthesis of the target compounds was readily accomplished through a reaction of acyl hydrazide (1) with carbon disulfide in the presence of alcoholic potassium hydroxide to afford the corresponding intermediate potassium thiocarbamate salt (2), which underwent cyclization reaction in the presence of excess hydrazine hydrate to the corresponding triazole thiol (3). Further cyclisation reaction with substituted benzoyl chloride derivatives in the presence of phosphorous oxychloride afforded the final 6-phenyl-indol-3-yl [1,2,4]-triazolo[3,4-b]-[1,3,4]-thiadiazole compounds (5a–l). The novel series showed selective sub-micromolar IC₅₀ growth-inhibitory activity against Bcl-2-expressing human cancer cell lines. The most potent 6-(2,4-dimethoxyphenyl) substituted analogue (5k) showed selective IC₅₀ values of 0.31–0.7 µM against Bcl-2-expressing cell lines without inhibiting the Bcl-2-negative cell line (Jurkat). ELISA binding affinity assay (interruption of Bcl-2-Bim interaction) showed potent binding affinity for (5k) with an IC₅₀ value of 0.32 µM. Moreover, it fulfils drug likeness criteria as a promising drug candidate. Full article

Four different new Schiff basses tethered indolyl-triazole-3-thione hybrid were designed and synthesized. X-ray single crystal structure, tautomerism, DFT, NBO and Hirshfeld analysis were explored. X-ray crystallographic investigations with the aid of Hirshfeld calculations were used to analyze the molecular packing of the studied systems. The H···H, H···C, S···H, Br···C, O···H, C···C and N···H interactions are the most important in the molecular packing of 3. In case of 4, the S···H, N···H, S···C and C···C contacts are the most significant. The results obtained from the DFT calculations indicated that the thione tautomer is energetically lower than the thiol one by 13.9545 and 13.7464 kcal/mol for 3 and 4, respectively. Hence, the thione tautomer is the most stable one which agree with the reported X-ray structure. In addition, DFT calculations were used to compute the electronic properties while natural bond orbital calculations were used to predict the stabilization energies due to conjugation effects. Both compounds are polar where 4 (3.348 Debye) has a higher dipole moment than 3 (2.430 Debye). Full article

The novel racemic secondary alcohol (±)-2-{[4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]sulfanyl}-1-phenyl-1-ethanol (12) has been successfully synthesized through S-alkylation of 4-(4-bromophenyl)-5-phenyl-4H-1,2,4-triazole-3-thiol (10) in alkaline medium with 2-bromo-1-phenylethanone followed by reduction of the corresponding ketone 11. All the synthesized compounds were characterized by IR, 1D (¹H, ¹³C, DEPT135) and 2D (¹H-¹H, ¹H-¹³C and ¹H-¹⁵N) NMR spectroscopy, elemental analysis and HRMS spectrometry. Full article

4-(4-Methylphenyl)-5-phenyl-4H-1,2,4-triazol-3-thiol (4) was alkylated to 2-{[4-(4-methylphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenylethan-1-one (5) in alkaline conditions using 2-bromo-1-phenylethanone. The alkylated compound (5) was reduced at the carbonyl group to the corresponding racemic secondary alcohol with an asymmetric carbon, (R,S)-2-{[4-(4-methylphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenyl-1-ethanol (6). Both synthesized compounds, ketone (5) and secondary alcohol (6), are new and have not yet been reported in the literature. All the synthesized compounds were characterized by IR, 1D and 2D ¹H-¹H, ¹H-¹³C and ¹H-¹⁵N NMR spectroscopy and by elemental analysis. Full article

4-(4-Methoxyphenyl)-5-phenyl--4H-1,2,4-triazole-3-thiol (4) was alkylated to 2-{[4-(-4-methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenylethan-1-one (5) in alkaline conditions using 2-bromo-1-phenylethanone. The alkylated compound (5) was reduced at the carbonyl group to the corresponding racemic secondary alcohol with an asymmetric carbon, (R,S)-2-{[4-(4-methoxyphenyl)-5-phenyl-4H-1,2,4-triazol-3-yl]thio}-1-phenyl-1-ethanol (6). Both synthesized compounds, ketone (5) and secondary alcohol (6), are new and have not been reported yet in the literature. All the synthesized compounds were characterized by IR, 1D and 2D NMR ¹H-¹H, ¹H-¹³C and ¹H-¹⁵N-NMR spectroscopy and by elemental analysis. Full article