M. Wrona
1983
Citations
0
Influential Citations
6
Citations
Journal
Journal of Electroanalytical Chemistry
Abstract
Summary The mechanism of the polarographic reduction of 2-thiouracil and its S-methyl and ethoxy derivatives with stabilized 2-thiol-4-keto or 2-thione-4-enol structure has been studied. 2-Thiouracil is not electroreducible in aqueous solutions. However, it exhibits a strong tendency to adsorption and association on the mercury electrode. 2-Thio-4-ethoxypyrimidine undergoes a 4 e − , 4 H + reduction which involves 2 e − reduction of the 3,4 N=C bond, elimination of the ethoxy substituent to form 2-thiopyrimidine and 2 e − , 2 H + reduction of the latter to 3,4-dihydroderivative. For 2-thiomethyluracil, a model compound of the 2-thiol-4-keto form, the electroactive centre is shifted to C-2 and in a 2 e − , 2 H + reduction process the sulphur substituent undergoes elimination, to give pyrimidone-4; the latter can be further reduced at more negative potentials to tetrahydroderivatives (4 e − -process). Biological implications of these results have been discussed.