博文

目前显示的是 七月, 2024的博文

762-04-9

762-04-9 New synthesis of trimethylsilyl esters of phosphorus(III) acids  Abstract: A novel synthetically important reaction has been developed for the quick, convenient, and high-yield preparation of trimethylsilyl esters of phosphorus(III) acids, synthetically valuable Michaelis–Arbuzov reaction precursors. Commercially and synthetically available initial compounds used are derivatives of propan-2-ol phosphorylated in the second position capable of long-term storage and available silylating reagents: hexamethyldisilazane, bis(trimethylsilyl)acetamide, and diethyl(trimethylsilyl)amine. Also, a stepwise reaction scheme of the starting compounds with silylating reagents has been proposed. Graphic abstract: [Figure not available: see fulltext.]. https://www.lookchem.com/CASDataBase_762-04-9.htm

74-79-3 A fluorescence turn on trypsin assay based on aqueous polyfluorene

https://www.lookchem.com/CASDataBase_74-79-3.htm   A new method based on the electrostatic interaction of a novel anionic water soluble polymer P1 with a positively charged polypeptide Arg6 was developed for a continuous and real time turn on assay for the enzymatic activity of trypsin under alkaline conditions with a limit of detection of 0.17 nM. This method was also able to screen the inhibitors of trypsin. P1 fluorescence intensity was significantly decreased by the positively charged Arg6 due to the electrostatic interaction, whereas the enzymatic action recovered P1 fluorescence due to the fragmentation of Arg6 into small positively charged fragments and these were unable to quench the P1 fluorescence. Therefore, by triggering the fluorescence intensity change, it was possible to assay the enzymatic activity. Use of water soluble conjugated polymer P1 and no labeling on the substrate enhances the utility of this method significantly. The Royal Society of Chemistry. 

75-18-3 Reactions of 1,2-dihaloethanes

 Reactions of 1,2-dihaloethanes with chalcogenide anions generated from elemental chalcogens and dimethylchalcogens were performed in the hydrazine hydrate-KOH system. The use of anions Se  x   2-  and Te  x   2-  (x = 1-4) resulted in ethylene evolution and chalcogen regeneration (or in increased x value in an anion). Oligomers of Thiokol type formed only in the reaction of the 1,2-dichloroethane with a mixture of potassium disulfide and diselenide. The reductive cleavage of oligomers obtained in the hydrazine hydrate-KOH system followed by methylation led to the formation of 1,2-bis(methylthio)ethane, 1-methylseleno-2- methylthioethane, and 1,2-bis(methylseleno)ethane. The features of substitution with chalcogenide anions in vicinal dihalides are discussed.  https://www.lookchem.com/CASDataBase_75-18-3.htm

Articles about 42900-54-9

 "Ruthenium-Catalyzed Selective Hydrogenation of Epoxides to Secondary Alcohols Thiyagarajan, Subramanian,Gunanathan, Chidambaram supporting information, p. 9774 - 9778 (2019/12/02) A ruthenium(II)-catalyzed highly selective Markovnikov hydrogenation of terminal epoxides to secondary alcohols is reported. Diverse substitutions on the aryl ring of styrene oxides are tolerated. Benzylic, glycidyl, and aliphatic epoxides as well as diepoxides also underwent facile hydrogenation to provide secondary alcohols with exclusive selectivity. Metal-ligand cooperation-mediated ruthenium trans-dihydride formation and its reaction involving oxygen and the less substituted terminal carbon of the epoxide is envisaged for the origin of the observed selectivity." https://www.lookchem.com/CASDataBase_42900-54-9.htm

7429-90-5 Chlorination of aluminium-copper alloys

 The chlorination of Al-Cu alloys is investigated by thermogravimetry, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and energy dispersive X-ray fluorescence, between 200 and 500 °C. The starting temperature for the chlorination of selected alloys is determined. Results indicate that the reactivity of the alloys is different from that of the pure metals. Analysis of the reaction products reveals that there are interactions between the different chlorides formed. These interactions lead to an enhancement in the copper chlorides volatilization and the formation of well-developed crystals of CuCl 2  instead of the mixture of CuCl 2  and CuCl that is obtained in the chlorination of pure copper. A schematic diagram that describes the chlorination mechanisms for the pure metals and AlCu alloys is presented. https://www.lookchem.com/CASDataBase_7429-90-5.htm

1008-76-0 Dopamine/serotonin receptor ligands. 10: SAR studies on azecine-type dopamine receptor ligands by functional

 On the basis of the benz[d]indolo[2,3-g]azecine derivative 1 (LE300), structure-activity relations were investigated in order to identify the pharmacophore in this new class of ligands. Various structural modifications were performed and the inhibitory activities at human cloned D 1 , D 2L , and D 5  receptors were measured by using a simple fluorescence microplate reader based calcium assay. Subsequently, the affinities of active compounds were estimated by radioligand binding experiments, Deleting one of the aromatic rings as well as replacing it by a phenyl moiety abolishes the inhibitory activities almost completely. Contraction of the 10-membered central ring decreases them significantly. The replacement of indole by thiophene or N-methylpyrrole reduces the inhibitory activity, whereas replacing the indole by benzene increases it. Finally, the hydroxylated dibenz[d,g]azecine derivative 11d (LE404) was found to be more active than the lead 1 in the functional calcium assay as well

Manufacrture Supply 99% Synephrine Hydrochloride CAS 5985-28-4

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  Detailed Product Information: Product Name: Synephrine Hydrochloride English synonyms:1-(4-Hydroxyphenyl)-2-(methylam ino)-ethanolhydrochloride;4-hydroxy-alph a-((methylamino)methyl)-benzenemethanohy drochloride;l-1-p-hydroxyphenyl-2-methyl amino-1-ethanolhydrochloride;p-hydroxy-a Chemicalbooklpha-((methylamino)methyl)-b enzylalcohohydrochloride;p-hydroxy-alpha- (methylaminomethyl)benzylalcoholhydrochl oride;p-methylaminoaethanolphenolhydroch lorid;SYNEPHRINEHCL;SYNEPHRINEHYDROCHLOR IDE Brand Name: Synephrine CAS No.: 5985-28-4 Molecular Formula:C9H14ClNO2 Molecular Weight: 203.67g/mol Purity : 99% HPLC Appearance: White Powder Typical use: Promote metabolism Weight loss Supplements Standard Packing : 100gram,1kg ,25kg Shelf Life :2 years Storage:Room temperature away from light Description: Synephrine is a biogenic amine .It is found at high levels in the peels of citrus plants, like bitter orange or Seville orange (Citrus aurantium). Extracts from fruits or peels of these plants ha