Facile and Straightforward Synthesis of Racemic Version of Substituted 3-[3-(2-Hydroxyphenyl)-3-oxo-1-arylpropyl]-4-hydroxycoumarins: Easy Access to a Series of Biorelevant Warfarin Analogues

Synthesis ◽  
2021 ◽  
Author(s):  
Goutam Brahmachari ◽  
Mullicka Mandal ◽  
Indrajit Karmakar
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Practical Method ◽  
Easy Access ◽  
Chromatographic Purification ◽  
Present Communication ◽  
Aqueous Potassium Hydroxide ◽  
Hydrolysis Of ◽  
Column Chromatographic ◽  
Operational Simplicity

AbstractThe present communication deals with a straightforward, efficient, and green synthesis of a series of racemic version of 3-[3-(2-hydroxyphenyl)-3-oxo-1-arylpropyl]-4-hydroxycoumarins as biologically interesting warfarin analogues upon decarboxylative hydrolysis of bis-coumarin derivatives in aqueous potassium hydroxide solution. The salient features of this practical method are operational simplicity, avoidance of any organic solvents and tedious column chromatographic purification, clean reaction profiles, excellent yields, and gram-scale synthetic applicability.

Reactions of tert-Butyl Peroxy Esters, XIV. Further Observations on the Preparation of Dialkyl tert-Butylperoxy Phosphates

1975 ◽  
Vol 30 (9-10) ◽  
pp. 732-739 ◽  
Author(s):  
G. Sosnovsky ◽  
E. H. Zaret
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Sodium Hydride ◽  
High Yield ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide ◽  
Aqueous Potassium Hydroxide ◽  
Butyl Peroxide

The preparation of dialkyl tert-butylperoxy phosphates (2, R = alkyl) has been achieved by the reaction of the corresponding dialkyl phosphorochloridates (1, R = alkyl) with tert-butyl hydroperoxide either in the presence of pyridine or in the presence of aqueous potassium hydroxide solution. Neither of these routes is suitable for the preparation of dialkyl tert-butylperoxy phosphates in quantity since they yield peroxyphosphates which are contaminated either with the corresponding tetraalkyl pyrophosphates or dialkyl phosphates; the contaminants cannot easily be removed by conventional means from the peroxyphosphates. The method of choice for the preparation in high yield of large quantities of pure dialkyl tert-butylperoxy phosphates involves the interaction of the corresponding dialkyl phosphorochloridate with sodium tert-butyl peroxide which has been prepared in situ from the reaction of tert-butyl hydroperoxide with sodium hydride.

KINETIC STUDIES OF THE AgO/Ag2O ELECTRODE IN ALKALINE SOLUTIONS

1964 ◽  
Vol 42 (11) ◽  
pp. 2488-2495 ◽  
Author(s):  
R. G. Barradas ◽  
G. H. Fraser
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Kinetic Studies ◽  
Alkaline Solutions ◽  
Hyperbolic Function ◽  
Electron Number ◽  
Rate Determining Step ◽  
Symmetry Factor ◽  
Tafel Slopes ◽  
Aqueous Potassium Hydroxide

The anodic oxidation of Ag2O to AgO in normal aqueous potassium hydroxide solution was investigated quantitatively under both galvanostatic and potentiostatic conditions at 25 °C. A few results for similar experiments in N/40 KOH are also reported. Tafel slopes and other parameters were determined. The experimental results show the dependence of current density as a hyperbolic function of overpotential, i.e. i = 2i0 sinh (λFη/2RT). The electron number λ was found to be 2 and the symmetry factor β was confirmed to be 1/2. It is proposed that the rate-determining step for the formation of AgO from Ag2O occurs at the Ag2O/AgO interface and involves the transfer of O−2 ions.

scholarly journals Wet Chemical Etching of AlN Single Crystals

2002 ◽  
Vol 7 ◽  
Author(s):  
D. Zhuang ◽  
J.H. Edgar ◽  
Lianghong Liu ◽  
B. Liu ◽  
L. Walker
Keyword(s):  
Single Crystals ◽  
Basal Plane ◽  
Chemical Etching ◽  
Potassium Hydroxide ◽  
Defect Density ◽  
Potassium Hydroxide Solution ◽  
Aqueous Potassium Hydroxide ◽  
Important Means ◽  
Wet Chemical ◽  
Image Position

Anisotropic chemical etching is an important means for characterizing the polarity and defect density of single crystals. In this letter, we present the results of our studies on the etching of bulk AlN crystals in aqueous potassium hydroxide solution. The nitrogen polarity (0001) basal plane initially etched rapidly, while the aluminum polarity basal plane, and prismatic (100) planes were not etched. The etch rate of the nitrogen polarity basal plane eventually decreased to zero, as the surface became completely covered with hexagonal hillocks which were bounded by {101} planes. The hillock density for the self-seeded AlN crystals studied was typically in the range of 5×107cm−2 to 109cm−2. From our analysis of etched AlN crystals, we infer that freely nucleated crystals predominately have the nitrogen to aluminum direction pointing out from the nucleation surface, that is the ends of the AlN crystals facing the source are aluminum polarity.

scholarly journals Synthesis and Antimicrobial Activity of SomeNovel Benzimidazolyl Chalcones

2009 ◽  
Vol 6 (1) ◽  
pp. 196-200 ◽  
Author(s):  
B. A. Baviskar ◽  
Bhagyesh Baviskar ◽  
M. R. Shiradkar ◽  
U. A. Deokate ◽  
S. S. Khadabadi
Keyword(s):  
Antimicrobial Activity ◽  
Elemental Analysis ◽  
Spectroscopic Data ◽  
Potassium Hydroxide ◽  
Room Temperature ◽  
Potassium Hydroxide Solution ◽  
Aromatic Aldehydes ◽  
Plate Method ◽  
H Nmr ◽  
Aqueous Potassium Hydroxide

Some novel benzimidazolyl chalcones were synthesized by condensation ofN-(4-(1H-benzo[d]imidazol-2-yl)phenyl)acetamide with aromatic aldehydes in presence of aqueous potassium hydroxide solution at room temperature. All the synthesized compounds were characterized on the basis of their IR,1H NMR spectroscopic data and elemental analysis. All the compounds have been screened for antimicrobial activity by the cup-plate method.

Chemical actinometry in the UV range based on the photohydrolysis of 3,4-dimethoxynitrobenzene

1986 ◽  
Vol 51 (2) ◽  
pp. 368-374 ◽  
Author(s):  
Libuše Pavlíčková ◽  
Petr Kuzmič ◽  
Milan Souček
Keyword(s):  
Light Intensity ◽  
Potassium Hydroxide ◽  
Uv Light ◽  
Excitation Wavelength ◽  
Spectral Absorption ◽  
Absorption Data ◽  
Aqueous Potassium Hydroxide ◽  
Hydrolysis Of ◽  
Uv Range

Photochemical hydrolysis of 3,4-dimethoxynitrobenzene in aqueous potassium hydroxide leading to the formation of 2-methoxy-5-nitrophenolate anion is routinely used for the determination of UV light intensity. The quantum efficiency of the actinometric system is independent on the excitation wavelength ( 254, 313, 365 nm) and reaches the value of 0.116 ± 0.002 in 0.5 M-KOH. The light intensity determination is based purely on UV/VIS spectral absorption data. A photokinetic model is presented for the reaction which is generally applicable for any photochemical system with the involvement of inner filtration due to products and partial light absorption. The evaluation of primary spectral data is performed by numerical integration of the photokinetic equation.

In vitro binding of sterols by extracts from Mucor rouxii cells grown under different environmental conditions

1976 ◽  
Vol 22 (8) ◽  
pp. 1163-1168 ◽  
Author(s):  
S. Safe ◽  
J. Caldwell
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Mucor Rouxii ◽  
Growth Environment ◽  
Cell Extracts ◽  
Relative Binding ◽  
Vitro Binding ◽  
Aqueous Potassium Hydroxide ◽  
Aerobic And Anaerobic

Aqueous cell wall and cytoplasm extracts from Mucor rouxii cells grown under aerobic and anaerobic (oxygen-limiting) conditions were obtained. Both of the extracts from the anaerobic and aerobic cells solubilized lanosterol and ergosterol but not to the same extent; ergosterol was complexed about 2–3 times greater than the same concentration of lanosterol. It was also apparent that the relative binding capacities of the cell extracts were dependent on the cell growth environment. Two additional fractions were obtained from each extract by (a) methanol precipitation and (b) refluxing in 2% aqueous potassium hydroxide solution followed by methanol precipitation. The binding activities of these precipitates and the corresponding precipitates from yeast extract were compared and the results indicated a range of binding activites which depended on both the extract and the sterol. The data suggested that the in vitro sterol binding of M. rouxii extracts was not due to one particular macromolecule but that a number of compounds were involved in this complexation process.

scholarly journals Morphology and photoluminescence of nanostructured oxides grown by copper passivation in aqueous potassium hydroxide solution

2017 ◽  
Vol 198 ◽  
pp. 89-92 ◽  
Author(s):  
Wojciech J. Stepniowski ◽  
Stevan Stojadinović ◽  
Rastko Vasilić ◽  
Nenad Tadić ◽  
Krzysztof Karczewski ◽  
...  
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Hydroxide Solution ◽  
Nanostructured Oxides ◽  
Aqueous Potassium Hydroxide ◽  
Copper Passivation
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