Reductions with sulfurated borohydrides. V. Reductions of ketones

1970 ◽  
Vol 48 (15) ◽  
pp. 2366-2371 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Freche

Ketones can be reduced with sulfurated sodium borohydride. Very high yield (≈90%) of the corresponding alcohol is obtained with the appropriate ratio of ketone and hydride at room temperature. The reaction is much influenced by the steric environment around the carbonyl group. At high temperature (65°) disulfides and tetrasulfides are produced. In some cases the structure of those sulfides have been established. Conjugated ketones can be reduced to the corresponding alcohols with very high yields.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hassan Kabirifard ◽  
Pardis Hafez Taghva ◽  
Hossein Teimouri ◽  
Niloofar Koosheshi ◽  
Parastoo Javadpour ◽  
...  

The reaction of 4-benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione (1) with aminoheteroaryls, lamotrigine, 1,3-diaminoheteroaryls, dapsone, NH2R (hydroxylamine, DL-1-phenylethylamine, and metformin), and 4,4′-bipyridine in THF/H2O (1 : 1) at room temperature led to 3-N-phenylthiocarbamoyl-2-butenamides 2–5, while that with naphthylamines and 1,3-phenylenediamine in ethanol at high temperature led to 5-phenylamino-2,5-dihydrothiophene-2-ones 6–8 as organic ligands in the medium to good yields. These showed the nucleophilic attacks of N-nucleophiles, except primary aromatic amines, on thioester carboxyl group (C-2) of thiophene-2,3-dione ring 1. However, the nucleophilic attacks of primary aromatic amines on the carbonyl group (C-3) of thiophene-2,3-dione 1 occurred in the form of substituted thiophenes.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  

Abstract Background With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE. Results Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected > 370 GBq (> 10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (> 98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (> 95%) and with apparent molar activities (9–25 MBq/nmol) sufficient for clinical use. Conclusions We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient to supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.


1982 ◽  
Vol 75 (1) ◽  
pp. 53-55
Author(s):  
George Knill ◽  
George Fawceti

Everyone knows that wood bums at a very high temperature. This burning is a chemical process that combines oxygen and carbon. The process occurs at very low temperatures as well as at very high ones. At high temperatures the process is spectacular-fire. At low temperatures (room temperature) you won’t even notice it, although it is still going on. Wood is always burning.


2016 ◽  
Vol 88 (4) ◽  
pp. 349-361 ◽  
Author(s):  
Ana R. Jesus ◽  
Ana P. Marques ◽  
Amélia P. Rauter

AbstractDihydrochalcones are polyphenols that exhibit a diversity of bioactivities, namely anti-inflammatory, antimicrobial and antiviral. We have explored the synthetic access to such molecular entities, and describe now an easy and scalable approach based on reduction of the olefinic double bond of chalcone precursors via in situ hydrogenation with the system Et3SiH-Pd/C in very high yield. The intermediate chalcones were synthesized also by a simple and efficient microwave-assisted Claisen–Schmidt condensation of aromatic aldehydes with acetophenones, conveniently protected with ethoxymethyl ether, if required. Chalcones were obtained as single reaction product in high yield in 2–3 h, while under conventional conditions at room temperature the reaction was carried out with completion only after 24 h. In addition, microwave irradiation has proven very efficient for deprotection of ethoxymethyl ether with iron chloride in only 10 min and very high yield.


2020 ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  

Abstract Background: With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE.Results: Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected >370 GBq (>10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the draft Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (>98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (>95%) and with apparent molar activities (9-25 MBq/nmol) sufficient for clinical use.Conclusions: We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient for supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.


2014 ◽  
Vol 1035 ◽  
pp. 303-306
Author(s):  
Xiao Ya Chen ◽  
Quan An Li ◽  
Qing Zhang ◽  
Jun Chen ◽  
Hui Zhen Jiang

The microstructure and mechanical properties of Mg-6Al-1Zn-0.9Y-1.8Gd alloy have been studied by micro-analysis and tensile tests. The results showed that the alloy mainly consists of Mg matrix, Al2Y, Mg17Al12and Al2Gd. The best tensile strength of the alloy was 255 Mpa at room temperature, and the alloy still had the very high mechanical property at high temperature.


2006 ◽  
Vol 84 (4) ◽  
pp. 667-675 ◽  
Author(s):  
Russell R Wolff ◽  
Vikram Basava ◽  
Robert M Giuliano ◽  
Walter J Boyko ◽  
J Herman Schauble

Reaction of alkenes and alkenols with N-iodosuccinimide (NIS) and benzenesulfinic acid in dichloromethane at room temperature affords vic-iodophenylsulfonyl adducts in good to high yields. Treatment of the iodosulfones with neutral alumina in dichloromethane at room temperature results in dehydroiodination to give the corresponding vinyl sulfones in high yield and purity by this convenient two-step procedure. Application of the iodosulfonation–dehydroiodination sequence to allylic alcohols and silyl ethers gave γ-oxygenated, α,β-unsaturated phenylsulfones, while the attempted iodosulfonation of glycals, as intermediates to vinyl sulfones, resulted in addition of benzenesulfinic acid with double bond shift (Ferrier rearrangement). Key words: iodosulfonation, vinyl sulfones, benzenesulfinic acid, N-iodosuccinimide, dehydroiodination.


1998 ◽  
Vol 547 ◽  
Author(s):  
M. S. Martín-Gonzilez ◽  
E. Morán ◽  
R. Sáez-Puche ◽  
M. Á. Alario-Franco

AbstractElectrodeposition of multimetallic films at room temperature on metallic substrates followed by oxidation at high temperature (~ 900°C) has often been employed to prepare high temperature superconducting (HTSC) films. A difficulty with this otherwise cheap and simple process is that the degree of surface covering is usually not very high. We have attempted to remediate this problem by sequentially repeating the deposition process on the same film. In this way, we have improved quite markedly critical current density (Jc) of films obtained on Silver substrates.To quote some figures, Jc at 1 T is ~ 400 A/cm2 after the first deposition/oxidation process and it increases to ~ 2 000 A/cm2 after the fourth one. The evolution of the morphology of the films has been followed by means of scanning electron microscopy (SEM). It shows that, although the degree of surface coverage never attains 100 %, a substantial proportion of the substrate is well coated.We have also studied the influence of mechanical pressure on the metallic film before the thermal treatment; after the fourth deposition, a pressure of ~15 KBar was applied. In this case a ~ 7% increase in Jc was observed and the density after compression (6.98 g/cm3) attains almost 100 % of the theoretical value for YBa2Cu3O7-δ (Ybacuo).


IUCrData ◽  
2018 ◽  
Vol 3 (12) ◽  
Author(s):  
Eric Sperlich ◽  
Martin Köckerling

The title compound bis(benzothiazolium) dodeca-μ-chlorido-hexachlorido-octahedro-hexaniobium(12 Nb—Nb) tetrahydrofuran disolvate, (C7H6NS)2[Nb6Cl18]·2C4H8O or (HBTh)2[Nb6Cl18]·2THF, is the first known niobium cluster compound to contain an N,S-heterocyclic cation. The synthesis takes place within a few hours as an one-pot reaction at room temperature of the cluster precursor compound [Nb6Cl14(H2O)4]·4H2O with SOCl2 in the presence of BTh (benzothiazole) in very high yield. The stabilization of the acidic proton of the cation is achieved by the use of tetrahydrofuran as a co-solvent and by the formation of hydrogen bonds.


Alloy Digest ◽  
1952 ◽  
Vol 1 (2) ◽  

Abstract Nicloy 9 is a tough, impact resistant nickel alloy steel applicable to sub-zero temperature uses. It has high physical properties with excellent ductility. Its toughness is very high at low temperatures. At room temperature it is only slightly sensitive to temper brittleness. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness and fatigue. It also includes information on high temperature performance and corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-2. Producer or source: Babcock & Wilcox Company.


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