
TY  - JOUR
A1  - Goyal, Rajendra N. 
A1  - Kumar, Neeraj 
T1  - Cyclic Voltammetry and Chronoamperometry of 1-Methylxanthine: Evidence for an Unstable <emph type="2">para</emph>-Quinonoid Diimine Intermediate
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1998
VL  - 52
IS  - 1
SP  - 43
EP  - 50
KW  - 
UR  - https://doi.org/10.1071/C98095 
N2  - The electrooxidation of the adenosine antagonist 1-methylxanthine has been studied in the pH range 2&#183;5&#8211;10&#183;7 at the pyrolytic graphite electrode. The initial 4e, 4H+ oxidation step leads to the formation of an unstable diimine, for which the half-life was found to be 1&#183;8 s by chronoamperometry. The diimine is readily attacked by water to give a carbinolamine which decomposes in a pseudo first-order reaction to give, as the major products, 1-methylalloxan at pH 3&#183;0 and 5-hydroxy-5-(methylcarbamoyl)hydantoin at pH 7&#183;0. The oxidation products were identified. The diimine can also be reversibly reduced to the 2,6,8-trioxopurine anion derivative which is also formed by the 2e, 2H+ reduction of the carbinolamine. A tentative mechanism for the formation of the products has also been suggested. 
ER  -

