scholarly journals Transformations of 3,7-interphenylene 11-deoxyprostanoid formyl precursors in the acidic medium

2021 ◽  
Vol 65 (6) ◽  
pp. 702-707
Author(s):  
F. S. Pashkovsky ◽  
D. I. Korneev ◽  
F. A. Lakhvich
Keyword(s):  
Acidic Medium ◽  
Aromatic Fragment ◽  
Acidic Hydrolysis ◽  
Α Chain ◽  
Hydrolysis Of

It has been shown that the formyl precursors of 3,7-interphenylene 11-deoxyprostanoids, formed during acidic hydrolysis of the corresponding acetals, can undergo isomerization (disproportionation) in the acidic medium to give 2-(arylalkyl)-3-(hydroxymethyl)cyclopent-2-ene-1-ones – the synthons for prostanoids and phytoprostanes of the series B. Acetal precursors of 3,7-interphenylene 11-deoxyprostaglandin analogues with electron-donating alkoxy substituent in position 3′ of the aromatic fragment in the α-chain under similar conditions hydrolyze with the formation of formyl derivatives that spontaneously cyclize to produce 2,3,4,9-tetrahydro-1H-cyclopenta[b]naphthalene-1-ones.

Kinetics of hydrolysis of peroxodisulphate ions in acidic medium to peroxomonosulphuric acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
Jan Balej ◽  
Milada Thumová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Medium ◽  
Measured Data ◽  
Molar Ratios ◽  
Starting Solution ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate of hydrolysis of S2O82- ions in acidic medium to peroxomonosulphuric acid was measured at 20 and 30 °C. The composition of the starting solution corresponded to the anolyte flowing out from an electrolyser for production of this acid or its ammonium salt at various degrees of conversion and starting molar ratios of sulphuric acid to ammonium sulphate. The measured data served to calculate the rate constants at both temperatures on the basis of the earlier proposed mechanism of the hydrolysis, and their dependence on the ionic strength was studied.

Insights into the Inhibition of Acidic Hydrolysis of Cellulose by Its Solation

2018 ◽  
Vol 6 (8) ◽  
pp. 10999-11007 ◽  
Author(s):  
Gongzhe Chen ◽  
Xicheng Wang ◽  
Yijun Jiang ◽  
Xindong Mu ◽  
Haichao Liu
Keyword(s):  
Acidic Hydrolysis ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Determination of Unconjugated and Total N-Acetyl-p-aminophenol (NAPA) in Urine and Serum

1967 ◽  
Vol 13 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Karel P M Heirwegh ◽  
Johan Fevery
Keyword(s):  
Liver Disease ◽  
Acid Hydrolysis ◽  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Accurate Method ◽  
Total N ◽  
Hydrolysis Of ◽  
Urine And Serum

Abstract A sensitive and accurate method is described for the determination of N-acetyl-p-aminophenol (NAPA) and its metabolites in urine and serum. In strongly acidic medium, p-aminophenol (PAP) resulting from differential extraction and acid hydrolysis of total NAPA and unconjugated NAPA, is diazotized and the diazonium salt coupled with N-(1-naphthyl)ethylenediamine (NED) in the presence of ethanol. The blue azo dye formed is determined spectrophotometrically. Application to liver disease is briefly reported.

DC Polarographic and Spectrophotometric Determination of Ampicillin Capsules

1980 ◽  
Vol 63 (5) ◽  
pp. 1049-1051
Author(s):  
Juan A Squella ◽  
Luis J Nunez-Vergara ◽  
Maximo Aros
Keyword(s):  
Absorption Band ◽  
Spectrophotometric Determination ◽  
Degradation Product ◽  
Uv Absorption ◽  
Acidic Hydrolysis ◽  
Average Recovery ◽  
Polarographic Wave ◽  
Spectrophotometric Methods ◽  
Hydrolysis Of

Abstract Polarographic and spectrophotometric methods are proposed for the determination of ampicillin in capsules. Acidic hydrolysis of ampicillin with 1% HCHO in 0.3N HCl yields a degradation product identified as 2-hydroxy-3-phenyl-6-methylpyrazine. This compound has a well defined UV absorption band at 380 nm and a polarographic wave at –0.55 V vs SCE, which can be used for analytical purposes. Individual capsule assays, composite assays, and recovery studies are described. The average recovery values and standard deviations (SD) for UV and polarographic determinations were 99.20% (SD 0.95) and 100.85% (SD 1.09), respectively

ChemInform Abstract: Acidic Hydrolysis of 2-Methylthio-7-chloro-5-phenyl-1,3,4-benzotriazepines.

ChemInform ◽  
1987 ◽  
Vol 18 (31) ◽  
Author(s):  
M. SCHLEUDER ◽  
S. BUTZKI ◽  
P. RICHTER ◽  
A. SOKOLOV
Keyword(s):  
Acidic Hydrolysis ◽  
Hydrolysis Of

ChemInform Abstract: Acidic Hydrolysis of 1,4-Diformyl-2,3,5,6-tetrasubstituted Piperazines.

1986 ◽  
Vol 17 (8) ◽  
Author(s):  
V. V. NURGATIN ◽  
B. M. GINZBURG ◽  
V. I. KOVALENKO ◽  
G. A. MARCHENKO
Keyword(s):  
Acidic Hydrolysis ◽  
Hydrolysis Of

scholarly journals Acidic hydrolysis of astilbin and its application for the preparation of taxifolin from Rhizoma Smilacis Glabrae

2020 ◽  
pp. 174751982094835
Author(s):  
Xiao-Lin Qiu ◽  
Qing-Feng Zhang
Keyword(s):  
Activation Energy ◽  
Kinetic Parameters ◽  
Hydrolysis Reaction ◽  
Simple Method ◽  
Acidic Hydrolysis ◽  
A Value ◽  
Hcl Concentration ◽  
Hydrolysis Of

The acidic hydrolysis of astilbin to produce its aglycone, taxifolin, was investigated in this study. The effects of aq. HCl concentration and temperature on the reaction were studied, and the kinetic parameters were calculated. The results showed that with higher aq. HCl concentration and temperature, the hydrolysis of astilbin became faster. The activation energy of the hydrolysis reaction under 1 mol L−1 aq. HCl was calculated with a value of 148.6 kJ mol−1. The reaction was successfully applied to produce taxifolin from a sample of Rhizoma Smilacis Glabrae. A simple method for the purification of taxifolin from Rhizoma Smilacis Glabrae was developed with purity of 97.5%.

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