10.1080/00397910802419680
The research focuses on the efficient synthesis of 7-amino-3-hydroxyindan-1-one, a three-dimensional, three-point scaffold with potential applications in constructing focused compound libraries for biological interactions. The synthesis is achieved through a three-step process: first, reacting 4-nitrophthalic anhydride with ethyl acetoacetate, acetic anhydride, and triethylamine in methylene chloride to produce compound 10; second, hydrolyzing and decarboxylating compound 10 with trifluoroacetic acid in acetonitrile to yield 4-nitroindan-1,3-dione (11); and third, reducing compound 11 using catalytic hydrogenation with 10% Pd/C in methanol to obtain the final product, 7-amino-3-hydroxyindan-1-one (7). The structure of compound 7 was confirmed using heteronuclear multiple bond correlation (HMBC) spectral studies. The article also details the preparation of N-substituted derivatives of compound 7 and provides their physical constants, spectral data, and yields. Analytical techniques used include NMR spectroscopy, LC/MS, and melting point determination, ensuring the purity and structure of the synthesized compounds.
10.14233/ajchem.2017.20199
The research focuses on the multicomponent one-pot synthesis and characterization of novel 4-furyl-1,4-dihydropyridines, which are compounds with significant pharmacological properties, including calcium channel blocking activities. The experiments involved the reaction of 5-arylfuran-2-carbaldehydes with ethyl acetoacetate and ammonium acetate in refluxing ethanol to yield the desired arylated products. The synthesized dihydropyridines were characterized using various analytical techniques such as elemental analysis, Fourier-transform infrared spectroscopy (FTIR), proton and carbon nuclear magnetic resonance (1H NMR and 13C NMR), and mass spectrometry. These analyses confirmed the structure and composition of the compounds, which were found to have potential applications in the field of pharmaceuticals.
10.1007/s10593-011-0778-0
The research focuses on the synthesis and study of pyrazole derivatives, specifically 1-aryl(heteraryl)pyrazol-5-ols and azopyrazoles, due to their potential applications as chemical agents for plant protection, chemico-pharmaceutical preparations, antioxidants, reagents, dyes, and pigments. The experiments involved the treatment of various hydrazines with acetoacetic ester to form hydrazones and subsequent cyclization to pyrazolols. Key reactants included 3,5-dichloropyrid-2-ylhydrazine, mono- and dinitrophenylhydrazines, and acetoacetic ester. The synthesized pyrazolols were then used in azocoupling reactions with diazonium salts to produce azopyrazoles, which were evaluated for their potential as azo dyes for coloring textile materials like wool and polycaproamide. The study also assessed the fungicidal activity of the synthesized compounds against common textile-damaging micromycetes. Analytical techniques employed included IR and UV spectra for compound characterization, 1H NMR spectroscopy for structural confirmation, and elemental analysis for verifying the composition of the synthesized compounds. The biological activity was evaluated using standard microbiological methods, and the coloration properties were assessed based on their stability to dry and wet wear and resistance to light fading.
10.1055/s-0030-1260067
The research investigates the use of 1-butyl-3-methylimidazolium-based room-temperature ionic liquids (RTILs) as organocatalysts for the synthesis of 1,4-dihydropyrimidinones and thiones through a one-pot multicomponent reaction. The study aims to develop a greener synthetic pathway for these compounds, which have a broad range of biological activities, including as mitotic kinesin Eg5 inhibitors. The researchers found that the ionic liquid [bmim][MeSO4] was effective as a catalyst, yielding high product yields in short reaction times, and could be recovered and reused for five consecutive reactions without significant loss of catalytic efficiency. The chemicals used in the process include various aryl, heteroaryl, and aliphatic aldehydes, 1,3-dicarbonyl compounds such as ethyl acetoacetate and cyclohexane-1,3-dione, and urea or thiourea. The study concludes that the methodology has potential for bulk synthesis due to its ecocompatibility and the recyclability of the catalyst.
10.1016/S1872-2067(12)60693-7
The study focuses on the synthesis of 4H-pyran derivatives using a silica-bonded N-propylpiperazine sodium n-propionate (SBPPSP) as a recyclable catalyst. The catalyst was prepared from commercially available and inexpensive starting materials and was used to catalyze the synthesis of various 4H-pyran derivatives, including 3,4-dihydropyrano[c]chromenes, 2-amino-4H-pyrans, 1,4-dihydropyrano[2,3-c]pyrazoles, and 2-amino-4H-benzo[e]chromenes. The chemicals used in the study included aromatic aldehydes, malononitrile, dimedone, ethyl acetoacetate, 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one, and α-naphthol, which served as reactants in the multi-component reactions to form the desired 4H-pyran derivatives. The purpose of these chemicals was to participate in condensation reactions under refluxing aqueous ethanol conditions, with SBPPSP facilitating the process and being easily recoverable and reusable, highlighting the environmental and economic benefits of the method.
10.1055/s-1982-30055
The research details an improved procedure for the Michael reaction of chalcones, a valuable C-C bond forming reaction commonly catalyzed by alkali metal hydroxides or alkoxides. The study aimed to achieve better results using weaker bases such as piperidine, tertiary amines, or quaternary ammonium hydroxides. The researchers found that partially dehydrated commercial barium hydroxide efficiently catalyzed Michael reactions of chalcones with active methylene compounds like ethyl malonate, ethyl acetoacetate, acetylacetone, nitromethane, and enolizable ketones such as cyclohexanone and acetophenone. The process involved stirring the components in ethanol at reflux or room temperature, yielding products with sharp melting points and single spots on T.L.C., and spectra that matched those of recrystallized products. The yields were generally higher than reported yields or at least of the same order, and the method was operationally simpler compared to other basic catalysts. The study concluded that while the barium hydroxide catalyst was cheap and easily prepared, its catalytic activity decreased over time when exposed to moist air, and the use of solvents other than ethanol or methanol led to poorer yields.
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