10.3906/kim-1711-97
The study focuses on the synthesis, solvatochromism, and biological activity of novel azo dyes that incorporate 2-pyridone and benzimidazole moieties. The azo dyes were synthesized through the diazotization of 4-(1H-benzo[d]imidazol-2-yl)aniline and subsequent coupling with substituted 3-cyano-2-pyridones. The dyes were characterized using UV-Vis, FT-IR, and NMR spectroscopy, as well as elemental analysis. The study explored the solvatochromism of the dyes across various solvents and investigated their tautomeric forms. Biological tests, including MTT assays, revealed that the dyes exhibit good biocompatibility and antiproliferative activity against tumor cell lines MDA-MB-231 and HCT-116, suggesting potential applications in cancer treatment.
10.1016/j.bmcl.2009.11.037
The research presents the synthesis and biological evaluation of novel 5-styryl and 5-phenethyl-substituted 2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoles, which are analogs of the drug dimebolin. The study focuses on the synthesis of these compounds and their activity against therapeutically relevant targets, such as serotonergic, adrenergic, histamine, and other receptors. The experiments involved the reaction of aryl acetylenes with tetrahydro-1H-c-carbolines in a biphasic system using DMSO, KOH, and a phase-transfer catalyst, leading to the formation of (Z)- and (E)-isomers of 2-methyl-5-styryl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indoles. Further hydrogenation yielded the desired 5-phenethyl derivatives. The structures of the compounds were confirmed using LC–MS and 1H NMR spectroscopy, with specific attention to the chemical shifts and coupling constants indicative of the (Z)- and (E)-isomers. The biological activities were assessed through cell-based assays, measuring the compounds' abilities to inhibit serotonin-induced responses, block histamine H1 receptors, and their affinities to various receptors, which were determined by displacement of radio-labeled ligands. The most potent compounds were further profiled against a panel of 31 therapeutic targets to determine their specificity.
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.
10.1016/j.carres.2007.09.006
The research aimed to develop a novel microwave-accelerated method for methylating soluble starch, which is a process traditionally achieved through more time-consuming and complex procedures. The study successfully demonstrated that soluble starch could be fully methylated in a significantly reduced time frame of 4.66 minutes with a 72% yield, using iodomethane and 30% potassium hydroxide under microwave irradiation. The methylated starch was then efficiently hydrolyzed using 60% formic acid followed by 0.05 M sulfuric acid, both under microwave conditions. The partially methylated monosaccharides were separated and identified through preparative paper chromatography and confirmed by their melting points and optical rotations. The study concluded that microwave irradiation is an effective method for starch methylation, offering a rapid and efficient alternative to traditional methods, without the need for an inert atmosphere or catalysts.
10.1039/b702411h
The study presents a concise synthetic route to the anti-cancer agents combretastatin A-4 and DMU-212 using the Ramberg–B?cklund reaction. Combretastatin A-4, isolated from the African tree Combretum caffrum, is a potent inhibitor of tubulin polymerization, while DMU-212 is a synthetic analogue with cancer chemoprotective activity. The synthesis of combretastatin A-4 begins with the coupling of thiol 13, prepared from 3,4,5-trimethoxybenzyl alcohol using Lawesson’s reagent, and bromide 14, using potassium hydroxide in ethanol. The resulting sulfide is oxidized with m-chloroperoxybenzoic acid to form sulfone 12. The Ramberg–B?cklund reaction, carried out under various conditions (Meyers, Chan, and Franck), converts sulfone 12 into the stilbene intermediate 15, which is then desilylated to yield combretastatin A-4. The study also explores the synthesis of other combretastatin analogues, including (E)- and (Z)-2012, using similar procedures. The Ramberg–B?cklund reaction is further applied to prepare DMU-212 from sulfone 29, derived from 4-methoxybenzyl mercaptan and bromide 17. The study highlights the efficiency and stereoselectivity of the Ramberg–B?cklund reaction in synthesizing these anti-cancer stilbenes and provides insights into the reaction's scope and limitations.
10.1016/0957-4166(90)90037-B
The research explores a method for synthesizing chiral a-amino ketones without racemization and their subsequent stereoselective reduction to amino alcohols. The study aims to develop a reliable and non-racemizing route for the synthesis of these compounds, which are important in the field of organic chemistry and pharmaceuticals. The key chemicals used in this research include a-amino acids, benzyl bromide, potassium carbonate (K2CO3), potassium hydroxide (KOH), methyllithium, and sodium borohydride (NaBH4). The researchers first doubly benzylated the nitrogen of a-amino acids to form N,N-dibenzyl amino acids, which were then converted into a-amino ketones. These ketones were reduced using NaBH4 under non-chelation control to form amino alcohols with high stereoselectivity. The study concludes that this method allows for the synthesis of chiral a-amino ketones without significant racemization, provided the conversion of amides to ketones is performed at low temperatures (-30°C to -40°C). The resulting amino alcohols were found to be enantiomerically pure, with enantiomeric excess (ee) values ranging from 98.5% to 100%. This work represents a significant advancement in the non-racemizing synthesis of chiral compounds and their stereoselective transformations.
10.1007/s00044-017-1903-0
The study investigates the impact of replacing the triazole ring with pyrazole or imidazole rings on the physicochemical properties of a click-based lead compound, A1, which was a selective inhibitor against VEGFR2. The researchers synthesized eight new derivatives and identified pyrazole derivative B2 as a promising new lead. B2 maintained A1's in vitro activity, with improved solubility at pH 2.0 and pH 7.4, and a log D value suggesting potential for further modification to enhance intestinal solubility. The study concludes that the triazole/diazole replacement can optimize the physicochemical properties of click-based lead compounds, highlighting B2's potential for drug development.
10.1016/j.tetlet.2009.01.048
The research aims to develop a novel two-step synthetic process for the creation of [1,4]oxazepin-2-ones, a family of chemically and pharmacologically interesting compounds, starting from Baylis–Hillman (BH) adducts. The study successfully demonstrated that this operationally simple method, performed under ambient conditions, yields 81–93% of the target [1,4]oxazepin-2-ones, thereby opening up new synthetic utility for BH adducts. Key chemicals used in the process include BH adducts, a-amino esters, and various catalysts, with KOH proving to be the most effective catalyst. The research concludes that this approach not only provides an efficient method for synthesizing 1,4-oxazepines but also highlights the potential for extending this methodology to other amino acid-derived chiral heterocycles.
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