An Improved Synthesis of 3,6-Dihydro-as-indacene

Synthesis ◽  
2020 ◽  
Author(s):  
Marcelo Preite ◽  
Elies Molins ◽  
Ivonne Chávez ◽  
Mungalimane K. Amshumali ◽  
Cesar Morales-Verdejo ◽  
...  

AbstractThis contribution describes an updated synthetic route to 3,6-dihydro-as-indacene along with full characterization of all inter­mediates. The title compound is prepared by Mannich condensation of 2-methylfuran with formaldehyde and dimethylamine hydrochloride, quaternization of the resulting amine with methyl iodide, and conversion into the ammonium hydroxide salt by treatment with silver oxide in water. Subsequent Hoffmann elimination and [6,6]-cycloaddition through pyrolysis produces a furanocyclophane, which after photooxidation, intramolecular cycloaddition, and dehydration with sodium carbonate affords 2,3,6,7-tetrahydro-1,8-dione-as-indacene. Reduction of this diketone gives a mixture of alcohols, which after dehydration under slightly basic or acidic conditions produces 3,6-dihydro-as-indacene. The structure is confirmed by X-ray diffraction, and all intermediates are characterized by means of 1H and 13C NMR spectroscopy.

2014 ◽  
Vol 69 (6) ◽  
pp. 737-741 ◽  
Author(s):  
Gustavo A. Echeverría ◽  
Oscar E. Piro ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

Ammonium acesulfamate, (NH4)C4H4NO4S, was prepared by the reaction of acesulfamic acid and ammonium carbonate in aqueous solution, and characterized by elemental analysis and 1H and 13C NMR spectroscopy. Its crystal and molecular structure was determined by single-crystal X-ray diffraction methods. The substance crystallizes in the orthorhombic space group Pnma with Z = 4 molecules per unit cell. The NH4+ ion generates medium to strong hydrogen bonds with the carbonylic oxygen, the iminic nitrogen and the sulfonyl oxygen atoms of the acesulfamate anion. The FTIR spectrum of the compound was also recorded and is briefly discussed.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 593
Author(s):  
Juan Miranda-Pizarro ◽  
Macarena G. Alférez ◽  
M. Dolores Fernández-Martínez ◽  
Eleuterio Álvarez ◽  
Celia Maya ◽  
...  

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.


2015 ◽  
Vol 68 (3) ◽  
pp. 357 ◽  
Author(s):  
Kevin P. Yeagle ◽  
Darryl Hester ◽  
Nicholas A. Piro ◽  
William G. Dougherty ◽  
W. Scott Kassel ◽  
...  

The aluminium complexes {[κ2-N,O-(t-BuNCOPh)]AlMe2}2 (2), [κ2-N,O-(t-BuNCOPh)]2AlMe (3), and [κ2-N,O-(t-BuNCOPh)]3Al (4) were prepared through the protonolysis reaction between trimethylaluminium and one, two, or three equivalents, respectively, of N-tert-butylbenzamide. Complex 2 was also prepared via a salt metathesis reaction between K(t-BuNCOPh) and dimethylaluminium chloride. Complexes 2–4 were characterized using 1H and 13C NMR spectroscopy. Single-crystal X-ray diffraction analysis of the complexes corroborated ligand : metal stoichiometries and revealed that all the amidate ligands coordinate to the aluminium ion in a κ2 fashion. The Al–amidate complexes 2–4 were viable catalyst precursors for the Meerwein–Ponndorf–Verley–Oppenauer reduction–oxidation manifold, successfully interconverting several classes of carbonyl and alcohol substrates.


2010 ◽  
Vol 93-94 ◽  
pp. 643-646
Author(s):  
Pusit Pookmanee ◽  
Supasima Makarunkamol ◽  
Sakchai Satienperakul ◽  
Jiraporn Kittikul ◽  
Sukon Phanichphant

Zinc oxide micropowder was synthesized by a microwave-assisted method. Zinc nitrate and ammonium hydroxide were used as the starting precursors with the mole ratio of 1:1. The white precipitated powder was formed after adding ammonium hydroxide until the pH of final solution was 9 and treated with the microwave radiation power at 1000 Watt for 2-6 min. The phase of zinc oxide micropowder was examined by X-ray diffraction (XRD). A single phase of hexagonal structure was obtained. The morphology and chemical composition of zinc oxide micropowder were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The particle was plate-like in shape with the range of particle size of 0.1-0.5 µm. The elemental composition of zinc oxide showed the characteristic X-ray energy value as follows: zinc of Lα = 1.012 keV, Kα = 8.630 keV and Kβ = 9.570 keV and oxygen of Kα = 0.525 keV, respectively.


2014 ◽  
Vol 805 ◽  
pp. 678-683
Author(s):  
Ângela da Costa Nogueira ◽  
Jocielys Jovelino Rodrigues ◽  
Liliane Andrade Lima ◽  
Meiry Glaúcia Freire Rodrigues

In this study catalysts Fe/SBA-15 were prepared for Fischer-Tropsch Synthesis. SBA-15 samples were synthesized under acidic conditions using triblock copolymer Pluronic as a template and tetraethyl orthosilicate as a silica source.The molar composition was: 1.0 TEOS: 0017 P123: 8.14 HCl: 168 H2O. Fe/SBA-15 catalysts with different iron loading (15 wt. % and 20 wt. %) were prepared by wetness impregnation of relative SBA-15 with the desired amount of aqueous iron nitrate. The obtained catalyst were characterized by X ray diffraction (XDR), nitrogen adsorption-desorption and energy dispersive X-ray spectrometry (EDX). After impregnation of Fe the XRD profiles were almost unchanged and exhibited the high diffraction peaks of SBA-15 at low angles. The analysis of nitrogen adsorption-desorption was observed that the values of specific surface area decreased as the concentration of metal impregnated increased. And by the EDX analysis verified that the iron contents obtained are close to nominal levels of iron.


2021 ◽  
Author(s):  
Deniz ÇOBAN ÖZKAN ◽  
Ahmet Türk ◽  
Erdal Celik

Abstract The present research demonstrates the synthesis and characterization of LaMnO3 perovskite powders using the sol-gel technique for dye-sensitive solar cell applications. With this respect, transparent solutions were prepared from La and Mn based precursors, distilled water and citric acid monohydrate. Ammonium hydroxide was incorporated into the La-Mn solution in order to neutralize/precipitate at 24oC for 1 hour in the air. The solution was allowed to evaporate on a hot plate device at 90 °C in the air. The obtained solutions were dried at 90 oC for 24 hours to form a xerogel structure, dried at 200 oC for 2 hours and consequently annealed at 500 and 850 oC for 2 hours in the air. Thermal, structural, microstructural, optical and magnetic properties of the powders were characterized through differential thermal analysis-thermogravimetry (DTA-TG), Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), Malvern zeta sizer (PSD), UV-vis spectrometer and vibrating sample magnetometer (VSM). The obtained results indicate promise, especially the low band range, that LaMnO3 powders can be used in dye-sensitized solar cells and can positively affect performance and efficiency.


Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 125 ◽  
Author(s):  
Csilla Enikő Czégéni ◽  
Sourav De ◽  
Antal Udvardy ◽  
Nóra Judit Derzsi ◽  
Gergely Papp ◽  
...  

A new synthetic method for obtaining [RhCl(cod)(NHC)] complexes (1–4) (cod = η4-1,5-cyclooctadiene, NHC = N-heterocyclic carbene: IMes, SIMes, IPr, and SIPr, respectively) is reported together with the catalytic properties of 1–4 in nitrile hydration. In addition to the characterization of 1–4 in solution by 13C NMR spectroscopy, the structures of complexes 3, and 4 have been established also in the solid state with single-crystal X-ray diffraction analysis. The Rh(I)-NHC complexes displayed excellent catalytic activity in hydration of aromatic nitriles (up to TOF = 276 h−1) in water/2-propanol (1/1 v/v) mixtures in air.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Diana Kostyukova ◽  
Yong Hee Chung

Iron oxide nanoparticles were synthesized by precipitation in isobutanol with sodium hydroxide and ammonium hydroxide. The isobutanol played a role of a surfactant in the synthesis. The nanoparticles were calcined for 100 min to 5 hours in the range of 300 to 600°C. The characterization of the samples by FTIR (Fourier-transform infrared) and XRD (X-ray diffraction) confirmed the formation ofγ-Fe2O3(maghemite) from Fe3O4(magnetite) at calcination at 300°C. The morphology and particle size were studied by SEM (scanning electron microscope). Nanoparticles in the range of 11–22 nm prepared at 0.09 M of ferrous chloride exhibited superparamagnetic properties. Nanoparticles synthesized with ferrous chloride and ammonium hydroxide at 75°C and calcined at 530°C for 2 h wereα-Fe2O3(hematite).


2017 ◽  
Vol 18 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Marina Z. Mijajlovic ◽  
Milos V. Nikolic ◽  
Dusan Lj. Tomovic ◽  
Andriana M. Bukonjic ◽  
Aleksandar Kocovic ◽  
...  

Abstract New platinum(IV)-complexes with S-alkyl derivatives of thiosalicylic acid (alkyl = benzyl-(L1), methyl-(L2), ethyl-(L3), propyl-(L4), butyl-(L5)) have been synthesized and characterized by microanalysis, infrared spectroscopy, and 1H and 13C NMR spectroscopy. Th e bidentate S,O ligand precursor, the S-butyl derivative of thiosalicylic acid (S-bu-thiosal), was prepared, and its crystal structure was determined. Single crystals suitable for X-ray measurements were obtained by slow crystallization from a DMSO-water system. S-bu-thiosal crystallized in a P21/c space group of a monoclinic crystal system with a = 8.0732 (3) Å, b = 19.6769 (4) Å, c = 8.2291 (3) Å and Z = 4. S-bu-thiosal also has a coplanar geometry.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5320
Author(s):  
Shouting Wu ◽  
Xi Liang ◽  
Fang Luo ◽  
Hua Liu ◽  
Lingyi Shen ◽  
...  

A phenazine-1-carboxylic acid intermediate was synthesized from the reaction of aniline and 2-bromo-3-nitro-benzoic acid. It was then esterified and reacted with hydrazine hydrate to afford phenazine-1-carboxylic hydrazine. Finally, 10 new hydrazone compounds 3a–3j were obtained by the condensation reaction of phenazine-1-carboxylic acid hydrazide and the respective aldehyde-containing compound. The structures were characterized by 1H and 13C NMR spectroscopy, MS and single crystal X-ray diffraction. The antitumor activity of the target compounds in vitro (HeLa and A549) was determined by thiazolyl blue tetrazolium bromide. The results showed that compound (E)-N′-(2-hydroxy-4-(2-(piperidine-1-yl) ethoxy) benzyl) phenazine-1-carbonyl hydrazide 3d exhibited good cytotoxic activity.


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