Electrochemical oxidation of hydroquinone, catechol, and some of their monosubstituted derivatives has been studied in the presence of 3-hydroxy-1H-phenalen-1-one (2) as a nucleophile in ...water/acetonitrile (80/20) solutions using cyclic voltammetry and controlled-potential coulometry methods. The results revealed that quinones derived from oxidation of hydroquinones and catechols participate in Michael addition reactions with 2. The formed adducts convert to the corresponding benzofuran derivatives via different mechanisms. In this work, we derived a variety of products with good yields using controlled potential electrochemical oxidation at a graphite electrode in an undivided cell.
Bisindolyl-p-quinones were synthesized via the regioselective addition of indoles to electrochemically generated quinone-imines in good yields. Display omitted
► Electrochemical study of ...4-(piperazin-1-yl)phenol in water/acetonitrile mixture. ► Electrochemical synthesis of bisindolyl-p-quinones. ► Regioselectivety in Michael-addition of indoles to quinone-imines. ► Electrochemistry as a “powerful tool” for the synthesis of organic compounds.
The electrochemical oxidation of 4-(piperazin-1-yl)phenols have been studied in the presence of indole derivatives as nucleophiles in water/acetonitrile mixture by means of cyclic voltammetry and controlled-potential coulometry. The reaction mechanism is believed to be oxidation of 4-(piperazin-1-yl)phenols, Michael addition reaction, oxidation of the formed adduct, another Michael addition reaction, oxidation of new adduct and hydrolysis (ECECEC). The results revealed that bisindolyl-p-quinones were synthesized through the regioselective addition of indoles to electrochemically generated quinone imines in good yields at carbon electrode in a divided cell.
The electrochemical oxidation of 2,5-dihydroxybenzoic acid （1） has been studied in the presence of 1,3- cyclopentadiene （2） as a diene in water/ethanol （40/60, v/v） mixture using cyclic voltammetry ...and controlled-potential coulometry. A plausible mechanism for the oxidation of 1 in the presence of 2 is presented. Compound 1 was converted into bis-adduct 5 via electrooxidation, Diels-Alder reaction of 2 to anodically generated 3,6-dioxocyclohexa-l,4-dienecarboxylic acid （lox）, decarboxylation reaction, electrooxidation and Diels-Alder reaction. The electrochemical synthesis of 5 was performed in a one- pot reaction, without toxic reagents, at a carbon electrode in a simple cell using an environmentally friendlv method.
This article focuses on the drug–drug interaction between acetaminophen (also known as paracetamol) and β-lactam antibiotics (amoxicillin, ampicillin and penicillin) studied by means of cyclic ...voltammetry and controlled potential coulometry. The results indicate a drug–drug interaction between N-acetyl- p-benzoquinone-imine (NAPQI) derived from the anodic oxidation of acetaminophen and β-lactam antibiotics. Also the cyclic voltammetric data were analysed by digital simulation to measure the observed homogeneous rate constants ( k
obs
) of the reaction of NAPQI with β-lactam antibiotics. The calculated k
obs
for the reaction between NAPQI and β-lactam antibiotics was found to vary in the order k
obs
amoxicillin
= k
obs
ampicillin
> k
obs
penicillin
at biological pH.
This article focuses on the drug-drug interaction between acetaminophen (also known as paracetamol) and β-lactam antibiotics (amoxicillin, ampicillin and penicillin) studied by means of cyclic ...voltammetry and controlled potential coulometry. The results indicate a drug-drug interaction between N-acetyl-p-benzoquinone-imine (NAPQI) derived from the anodic oxidation of acetaminophen and β-lactam antibiotics. Also the cyclic voltammetric data were analysed by digital simulation to measure the observed homogeneous rate constants (kobs) of the reaction of NAPQI with β-lactam antibiotics. The calculated kobs for the reaction between NAPQI and β-lactam antibiotics was found to vary in the order kobsamoxicillin = kobsampicillin > kobspenicillin at biological pH.
