Refernces
10.1007/s00706-007-0649-7
The research focuses on the synthesis of novel heterocyclic compounds, specifically 1,2,4-triazol-3-ylmethyl-, 1,3,4-oxa-, and -thiadiazol-2-ylmethyl-1H-[1,2,3]-triazolo[4,5-d]pyrimidinediones, which are potentially useful as antiviral agents against hepatitis B virus. The experiments involved the synthesis of 1-carbethoxymethyl-4,6-dimethyl-1H-[1,2,3]triazolo[4,5-d]pyrimidine-5,7(4H,6H)-dione and its subsequent reactions with hydrazine hydrate to yield a hydrazide. This hydrazide was further reacted with phenylisothiocyanate or carbon disulfide and KOH to produce thiosemicarbazide and oxadiazole derivatives. Various alkylation and cyclization reactions were performed to form the desired heterocyclic structures, including the formation of 1,3,4-thiadiazole, 5-mercapto-1,2,4-triazole, and 1,3,4-oxadiazole rings. The synthesized compounds were analyzed using techniques such as infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS) to confirm their structures. The reactants used in these syntheses included phenylisothiocyanate, carbon disulfide, alcoholic potassium hydroxide, dimethyl sulfate, ethyl chloroacetate, and various monosaccharide aldoses. The synthesized compounds were tested for their antiviral activity, with some showing moderate activities against hepatitis B virus.
10.1016/j.saa.2013.10.086
The study focuses on the synthesis and evaluation of novel azo dye-thiosemicarbazone derivatives (sensors 3a–f) as selective colorimetric chemosensors for anion detection, particularly for acetate anions. These sensors were synthesized through a condensation reaction between thiosemicarbazide and various azo salicylaldehydes. The chemicals used in the study include thiosemicarbazide, azo salicylaldehydes, and tetra-n-butylammonium salts of different anions (acetate, fluoride, chloride, iodide, and dihydrogenphosphate). The purpose of these chemicals was to create a series of sensors that could selectively recognize and detect acetate anions over other anions through a visible color change, which was confirmed by spectroscopic methods and UV–vis spectra. The study demonstrated that sensor 3e, with a nitrophenyl substituent, showed the most remarkable color change and selectivity for acetate anions, making it a potential candidate for practical analysis and application in detecting acetate ions in aqueous solutions.
10.1016/j.ejmech.2011.09.034
The study focuses on the synthesis and evaluation of 4-arylthiosemicarbazides as potential topoisomerase IV inhibitors with antibacterial activity against Gram-positive bacteria. The researchers synthesized 1-(indol-2-carbonyl)-4-(4-nitrophenyl)-thiosemicarbazide and assessed its antibacterial activity and its ability to inhibit type IIA topoisomerases, which are essential enzymes in bacterial DNA replication. The study aimed to understand the structure-activity relationship (SAR) of these compounds and explore their molecular basis for antibacterial activity. The synthesized thiosemicarbazide derivatives were tested for their antibacterial potency and their ability to inhibit topoisomerase IV, with the goal of finding new chemical entries for antibiotics. The study also involved molecular modeling and docking studies to understand the interaction of these compounds with the target enzymes.
10.1021/jo0618730
The study presents a novel and efficient method for synthesizing 2-amino-1,3,4-oxadiazoles, which are important pharmacophores due to their metabolic stability and hydrogen bonding capabilities. The key chemicals involved include thiosemicarbazides, which are prepared by acylating hydrazides with isothiocyanates. The thiosemicarbazides are then cyclized using tosyl chloride and pyridine in THF under reflux conditions to form the desired 2-amino-1,3,4-oxadiazoles. This method consistently outperforms the analogous semicarbazide cyclization, yielding 5-alkyl- and 5-aryl-2-amino-1,3,4-oxadiazoles in high yields (78-99%). The study highlights the superior reactivity of thiosemicarbazides compared to semicarbazides in this cyclization process, and it demonstrates the generality of this approach with various substituents. Additionally, the study shows that the thiosemicarbazides can be used directly from the crude acylation reaction mixture without purification, making the synthesis a convenient two-step, one-pot process. This method provides an efficient and robust route for the preparation of a wide variety of 2-amino-1,3,4-oxadiazoles, which are valuable in medicinal chemistry for their diverse biological activities.
10.1016/j.ejmech.2016.06.014
The research focuses on the synthesis and antimicrobial activity of a novel class of mono and bis heterocycles, including styryl, pyrrolyl, and pyrazolyl sulfonylmethyl-1,3,4-oxadiazolyl/thiadiazolyl amines. The study utilizes Z-styrylsulfonylacetic acid as a synthetic intermediate and employs various synthetic methodologies to prepare these compounds. The antimicrobial activity of these synthesized compounds was then evaluated against different bacterial and fungal strains. The reactants used in the synthesis encompass semicarbazide, thiosemicarbazide, POCl3, tosylmethyl isocyanide, sodium hydride, diazomethane, and chloranil, among others. The synthesized compounds were characterized using techniques like infrared (IR) spectroscopy, nuclear magnetic resonance (NMR), high-resolution mass spectrometry, and elemental analysis. The antimicrobial activity was assessed using the agar well diffusion method and broth dilution test to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC). The findings revealed that mono heterocyclic compounds, particularly 5-(4-chlorostyrylsulfonylmethyl)-1,3,4-thiadiazol-2-amine (5c), exhibited superior antimicrobial activity against certain bacteria and fungi compared to the bis heterocyclic systems.
10.1016/j.bmc.2008.02.052
The research focuses on the synthesis and in vitro anti-leishmanial activity of nitroheteroaryl-1,3,4-thiadiazole-based compounds, specifically 1-[5-(5-nitrofuran-2-yl)-1,3,4-thiadiazol-2-yl]-4-aroylpiperazines and 1-[5-(5-nitrothiophen-2-yl)-1,3,4-thiadiazol-2-yl]-4-aroylpiperazines. The study involves the synthesis of these compounds using reactants such as 5-nitro-2-arylidene diacetates, thiosemicarbazide, ammonium ferric sulfate, and various aroyl chlorides. The synthesized compounds were then tested for their anti-leishmanial activity against both promastigote and amastigote forms of Leishmania major. The experiments utilized MTT assay to determine the IC50 values, which indicate the potency of the compounds. The analysis included the calculation of the logarithm of the partition coefficient (LogP) to assess the lipophilicity of the compounds, which is an important factor in their biological activity. The results showed that most of the synthesized compounds exhibited potent anti-leishmanial activity at non-cytotoxic concentrations, with 5-nitrofuran derivatives generally being more active than the corresponding 5-nitrothiophene analogues.
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