Electrochemical dealkylation of aliphatic tertiary and secondary amines

Voltammetric Determination of Microparticles of Some Local Anesthetics and Antithusics Immobilized on the Graphite Electrode

“…It may be assumed that the electroactive centers in the investigated molecules are either aniline groups in benzocaine and procaine [6 ± 8], or amide groups in cinchocaine and lidocaine [9], or tertiary aliphatic amines in procaine, cinchocaine, lidocaine and codeine [10,11]. Esters, ethers and alcohols can not be oxidized at potentials lower than 2 V (vs. SCE) [12].…”

“…Oxidations of 4'-methoxybenzanilide, triethylamine and ethyldicyclohexylamine occur at about 1 V (vs. SCE) [9], 0.7 V [10] and 0.5 V [17]. These electrode reactions are followed by rapid hydrolyses and decompositions of the products [11]. However, the oxidations of numerous N,N-dimethylaminoalkenes occur in the potential range between À 0.9 Vand 0.5 V (vs. SCE) and the products are radical cations that are stable in acetonitrile [18 ± 21].…”

Identification of 5-aminosalicylic acid, ciprofloxacin and azithromycin by abrasive stripping voltammetry

“…Within an interval 1 < pH < 10, the peak potentials are independent of pH in both techniques. According to the literature data [26,29], it is not known which part of ciprofloxacin molecule is oxidized in the electrode reaction but it can be assumed that it is one of three amino groups that is oxidized to the cation radical [31][32][33][34][35][36][37]. This reaction is followed by the fast and totally irreversible transformation of the molecule either by the dimerization [31,33], or by the reaction with water [34][35][36][37].…”

“…The origin of the first peak is not known, but the main peak is ascribed to the oxidation of dimethy- lamino group on the desosamine sugar part of the molecule [27]. The product of this electrode reaction is cation radical, which undergoes irreversible transformation by the reaction with water [31][32][33][34][35][36][37]. This attribution is based on the fact that erythromycin, which is structurally analogous but has no nitrogen atom in macrocyclic lactone ring, exhibits similar voltammetric response [38].…”

Chapter 1. In situ electron paramagnetic resonance (EPR) – a unique tool for analysing structure and reaction behaviour of paramagnetic sites in model and real catalysts

“…Considering the stability of the radicals of tertiary, secondary and primary amines (at the N, a-and b-C), this signal was assigned to the primary H 2 NCH 2 C H 2 radical or the H 2 N 1 CH 2 C H 2 radical cation which is formed as a result of oxidative degradation of TEA, during which other short-lived radical intermediates may be passed. 83,92 The spectrum has been satisfactorily reproduced by assuming g ¼ 2.0017 and hfs by two sets of two equivalent protons (2H, A H1 ¼ 28.3 G, Fig. 11b), while hfs from the N nucleus is missing.…”