نتایج جستجو برای: potassium carbonate

تعداد نتایج: 101636  

Journal: :Organic letters 2001
A M Hafez A E Taggi H Wack J Esterbrook T Lectka

[reaction: see text] We have developed an efficient methodology for the generation of ketenes by employing a catalytic shuttle base and potassium carbonate as a stoichiometric base. We have applied this technology to the catalytic, asymmetric alpha-bromination of acid chlorides.

2009
K. Sivakumar R. Karuppasamy

Hydrological studies were made for 6 months covering monsoon, summer and transition periods in a reservoir, chiefly to understand the plankton productivity. The physical factors like temperature, light, pH and chemical factors like dissolved O , CO , carbonate, bicarbonate, chloride, nitrate, phosphate, sulphate, calcium, 2 2 magnesium, sodium and potassium were estimated.

2013
Martyn Inman Christopher J Moody

The reaction of enamines and bromoquinones in the presence of copper(II) acetate and potassium carbonate results in a regiospecific synthesis of indolequinones. The reaction is broad in scope and scalable and provides a route to the core structure that is present in several biologically interesting natural and synthetic compounds.

Journal: :Organic & biomolecular chemistry 2008
Michinori Karikomi Matthias D'hooghe Guido Verniest Norbert De Kimpe

2-(Bromomethyl)-1-sulfonylaziridines were converted into novel 3-sulfonamido-2,3,4,5-tetrahydro-1,5-benzothiazepines upon treatment with 2-aminothiophenol in THF in the presence of K2CO3. Starting from 3-substituted 2-(sulfonyloxymethyl)aziridines, a regio- and stereocontrolled synthesis of trans-2-phenyl- and trans-4-(phenyl or propyl)-3-sulfonamido-2,3,4,5-tetrahydro-1,5-benzothiazepines was ...

2007
M K Aydinol

Potassium nitrate exhibits a reentrant phase transformation, where a metastable ferroelectric phase (γ -KNO3) is formed upon cooling from high temperature. The layered structure of this ferroelectric phase is composed of alternating layers of potassium ions and nitrate groups; wherein, a central nitrogen atom is coordinated by three equilateral triangular oxygen atoms. The group layer is locate...

2000
P. R. MUSSINI T. MUSSINI S. RONDININI A. A. Vlcek

Recommended Reference Value Standards based on the potassium hydrogenphthalate buffer at various temperatures are reported for pH measurements in various binary solvent mixtures of water with eight organic solvents: methanol, ethanol, 2-propanol, 1,2-ethanediol, 2-methoxyethanol (“methylcellosolve”), acetonitrile, 1,4-dioxane, and dimethylsulphoxide, together with Reference Value Standards base...

Journal: :The Journal of organic chemistry 2006
Laijun Zhang Ji Zheng Jinbo Hu

A novel and non-ODS-based (ODS = ozone-depleting substance) preparation of 2-chloro-2,2-difluoroacetophenone (1) was achieved in high yield by using 2,2,2-trifluoroacetophenone as the starting material. Compound 1 was found to act as a good difluorocarbene reagent, which readily reacts with a variety of structurally diverse phenol derivatives 4 in the presence of potassium hydroxide or potassiu...

2010
Shui Liang Guo Chen Fu Ting Bin Wen

The title compound, C(14)H(15)NO(5), was obtained from the reaction of acetanilide with dimethyl acetyl-enedicarboxyl-ate in the presence of potassium carbonate. The C=C double bond adopts an E configuration and the geometry around the amide N atom is almost planar rather than pyramidal (mean deviation of 0.0032 Å from the C(3)N plane). The packing of the mol-ecules in the crystal structure is ...

Journal: :Batteries & supercaps 2023

In this study, the formation of dicarbonate degradation products ethylene carbonate‐based carbonate mixtures containing dimethyl carbonate, ethyl methyl or diethyl that were combined with lithium potassium metal, is investigated. It shown by NMR and GCMS dioxahexane dioate, dioate are formed from reactants to different extents and, in particular, surface initiates fast corresponding products. E...

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