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.
10.1007/s00706-008-0900-x
The study presents an efficient method for synthesizing ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates, which are compounds with potential applications in various fields such as agrochemicals, pharmaceuticals, and material chemistry. The synthesis involves a three-component reaction using carbon disulfide (CS2), primary amines (alkylamines), and diethyl 2-chloromalonate. These chemicals serve as reactants in the synthesis process, with CS2 and primary amines reacting to form an intermediate adduct, which then reacts with diethyl 2-chloromalonate to produce the final product. The study highlights the advantages of this procedure, including its simplicity, as it is performed under neutral conditions by simply mixing the starting materials, and its efficiency, yielding the desired products in good yields.
10.1021/acs.joc.0c01516
The study focuses on the synthesis of 2,5-disubstituted thiophenes and 2-substituted benzo[b]thiophenes using the trithiocarbonate anion (CS32-) as a sulfur source. This anion was generated in situ from carbon disulfide (CS2) and potassium hydroxide (KOH) in dimethyl sulfoxide (DMSO). The purpose of these chemicals is to serve as a novel synthetic equivalent of the S2- synthon, which is used for the cyclization of 1,3-butadiynes and 2-haloalkynyl (hetero)arenes. The study aims to provide a cheap and readily available method for the synthesis of these compounds, which have applications in various fields such as biochemistry, materials chemistry, and organic synthesis. The use of CS32- allows for metal-free cyclization reactions, offering a moderate to good yield of the target compounds with good functional group tolerance.
10.1002/cmdc.201402234
The research focuses on the synthesis and structure–activity relationship (SAR) studies of 2(1,3,4-Oxadiazole-2(3H)-thione)-3-amino-5-arylthieno[2,3b]pyridines as inhibitors of DRAK2 (DAPK-related apoptosis-inducing protein kinase 2). DRAK2 is a serine/threonine kinase that plays a crucial role in T-cell mediated autoimmune diseases and graft rejection. The study aims to develop new therapeutic targets to prevent allograft rejection without compromising the recipient's immune response to infections. The researchers used a proprietary compound library to identify a benzothiophene analogue with an affinity constant (Kd) value of 0.25 mm. Through variation of the core scaffold and substitution pattern, they synthesized a series of 5-arylthieno[2,3-b]pyridines with strong binding affinity, with the most potent representative having a Kd of 0.008 mm. These compounds also showed promising activity in a functional biochemical DRAK2 enzyme assay, with an IC50 value of 0.029 mm for the most potent congener. Key chemicals involved in the synthesis include ethyl thioacetate, hydrazine monohydrate, carbon disulfide, and various arylboronic acids used in Suzuki coupling reactions. The study provides valuable insights into the development of selective and potent DRAK2 inhibitors, which could serve as lead compounds for drug discovery programs targeting autoimmune diseases and organ transplantation rejection.
10.1016/S0040-4020(97)10136-3
The study investigates two methods for reducing ketene dithioacetals to produce substituted dithianes, which serve as building blocks for heterocyclic synthesis. The researchers, John M. Mellor, Stephen R. Schofield, and Stewart R. Korn, compared the effectiveness of magnesium in methanol and zinc in acetic acid for this reduction process. They found that zinc in acetic acid was more reliable than magnesium in methanol, which showed inconsistent results due to steric constraints in certain substrates. The study also involved the preparation of various ketene dithioacetals using two methods: reaction of carbon disulfide with the enolate anion of appropriate 1,3-dicarbonyl compounds in dimethylformamide or on alumina. The resulting dithianes were then successfully converted into heterocyclic aldehydes through cyclization and deprotection steps, demonstrating their utility in synthesizing complex heterocyclic structures.
10.1007/s00044-013-0887-7
This research presents the synthesis and anticonvulsant evaluation of new 6-bromoimidazo[1,2-a]pyridine-2-carbohydrazide derivatives, which are designed to possess biologically active hydrazone functionality and substituted 1,2,4-triazole moieties. The purpose of the study was to develop novel antiepileptic drugs with improved therapeutic actions and reduced toxicity. The synthesis involved various chemicals such as 5-bromo-2-aminopyridine, ethyl bromopyruvate, hydrazine hydrate, aromatic aldehydes, carbon disulfide, potassium hydroxide, and different alkyl/benzyl halides. The structures of the synthesized compounds were confirmed through spectral techniques like FTIR, 1H NMR, 13C NMR, and mass spectrometry. The in vivo anticonvulsant properties were assessed using maximal electroshock seizure and subcutaneous pentylene tetrazole methods, with toxicity studies performed using the rotarod method. The research concluded that most of the new compounds exhibited significant anticonvulsant properties without toxicity up to 100 mg/kg, with compounds 3b and 4 showing complete protection against seizures, comparable to the standard drug diazepam. These findings suggest that linking imidazo[1,2-a]pyridines with triazole and hydrazone moieties can lead to potent anticonvulsants with minimal side effects.
10.1039/c39860001179
The research aimed to explore the Diels-Alder cycloaddition reaction involving unactivated 2-aza-1,3-dienes with electron-poor dienophiles, such as dialkyl azodicarboxylates and heterocumulenes. This study was significant as it provided the first example of such a reaction with electronically neutral 2-azadienes, challenging the previous notion that these azadienes required electron-donating substituents to react with electron-poor dienophiles. The researchers successfully demonstrated that 2-azadienes could participate in [4+2] cycloadditions with simple aldehydes and carbon disulfide, yielding products like 1,2,3,6-tetrahydro-1,2,4-triazines and 1,2-dihydropyrimidin-4(3H)-ones, among others. The study concluded that unactivated 2-aza-1,3-dienes have potential in cycloaddition reactions, particularly with electron-poor dienophiles, showcasing a high yield and selectivity in the reactions. Key chemicals used in the process included 2-azadienes of type (1), dialkyl azodicarboxylates (3), isocyanates (5), isothiocyanates, and carbon disulfide (5) with catalytic amounts of BF3.Et2O.
F, 
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F:Flammable;
