107-81-3Relevant articles and documents
A novel route for the synthesis of alkanes from glycerol in a two step process using a Pd/SBA-15 catalyst
Udayakumar,Pandurangan
, p. 78719 - 78727 (2015)
Glycerol is produced as a valuable by-product in the transesterification of fatty acids, but it cannot be used directly as a fuel additive. In this study, we developed a systematic conversion for glycerol, which proceeds via synthesizing the key intermediate, 1,2,3-tribromopropane and using the Suzuki coupling reaction to introduce the alkyl group. A series of Pd/SBA-15 catalysts with different wt% of Pd (10%, 15% and 20%) was prepared by a one step sol-gel method. The structure and composition of the catalysts were characterized by X-ray diffraction analysis (XRD), N2 adsorption-desorption isotherms, transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectrometry (ICP-OES). The metallic state of dispersed palladium in SBA-15 is confirmed with X-ray photoelectron spectroscopy (XPS). Pd/SBA-15 with a Pd loading of 20 wt% shows good catalytic activity at 90 °C with methylboronic acid, allowing the complete conversion of 1,2,3-tribromopropane and 64% selectivity of 3-methylpentane. The optimized catalysts were also employed in coupling reactions between various alkylhalides and methylboronic acid, which obtained the desired product with an excellent selectivity. The catalyst can be successfully recycled five times. After the first cycle, we observed a drop in activity with 20% Pd/SBA-15, which was due to the leaching of palladium but in the later cycles, there was no significant decrease in activity.
Dehydrohalogenation of haloalkanes promoted by metal halides. Hydrogen halometalates formation and their use as hydrohalogenating agents
Suarez, Angela R.,Martin,, Sandra E.,Martinelli, Marisa,Domine, Marcelo E.,Mazzieri, Maria R.
, p. 7375 - 7386 (1998)
In the dehydrohalogenation of 1,2-dihalo-1,1-diphenylethanes, 1, to 2- halo-1,1-diphenylethene, 2, either at 76°C or at 50°C, promoted by catalytic amount of the anhydrous bromides of Fe(III), Ru(III) and Al(III) and Fe(III) chloride the chemical transformation of the metal halides was observed. In reactions carried out in vacuum or under nitrogen atmosphere, the hydrogen halide eliminated from the organic substrate reacted with the metal halides rendering the unstable hydrogen perhalometalates H+(a)[MX(2+a)]a-. We demonstrate that these compounds behave as hydrogen halide donors in hydrohalogenation of olefins at 4°C.
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Pines et al.
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Galpern
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Sherrill
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Hutchins et al.
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High-purity 5-ethyl-5-(1-methylbutyl)barbituric acid preparation method
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Paragraph 0021; 0022; 0025; 0026; 0029; 0030; 0033; 0034, (2019/10/04)
The present invention relates to a preparation method of a drug pentobarbital (1) for sedation, hypnosis, pre-anesthesia administration and anti-convulsion, and provides a new preparation process for preparing high-purity pentobarbital (I) from diethyl ethylmalonate, wherein the process comprises three steps: A, bromination; B, alkylation; and C, cyclization, acidification, and purification. According to the present invention, the method has advantages of simple operation, short production cycle, low energy consumption, mother liquor circulation, less three-waste, stable process, good product quality, high product purity, isomer impurity content of less than 0.1%, high yield and low production cost, and is suitable for industrial production.
Terminal-Selective Functionalization of Alkyl Chains by Regioconvergent Cross-Coupling
Dupuy, Stéphanie,Zhang, Ke-Feng,Goutierre, Anne-Sophie,Baudoin, Olivier
supporting information, p. 14793 - 14797 (2016/11/23)
Hydrocarbons are still the most important precursors of functionalized organic molecules, which has stirred interest in the discovery of new C?H bond functionalization methods. We describe herein a new step-economical approach that enables C?C bonds to be constructed at the terminal position of linear alkanes. First, we show that secondary alkyl bromides can undergo in situ conversion into alkyl zinc bromides and regioconvergent Negishi coupling with aryl or alkenyl triflates. The use of a suitable phosphine ligand favoring Pd migration enabled the selective formation of the linear cross-coupling product. Subsequently, mixtures of secondary alkyl bromides were prepared from linear alkanes by standard bromination, and regioconvergent cross-coupling then provided access to the corresponding linear arylation product in only two steps.
