K. Chiang
1958
Citations
0
Influential Citations
0
Citations
Journal
Acta Chimica Sinica
Abstract
Several typical 4, 5-dihydroxypyrimidines and other two pyrimidines havebeen studied polarographically using a micro platinum electrode as anode (andS. C. E.). The results are as follows: 1. Methanol, ethanol, benzene, chloroform, and formic acid are not suitable assolvents for 5-hydroxypyrimidines. The solvent used is acetic acid. 2. 2-Methyl-4, 5, 6-trihydroxypyrimidine (Ⅹ), three 2-substituted 5, 6 (4)-di-hydroxypyrimidines (Ⅺ, Ⅻ, ⅩⅢ), and 5, 6 (4)-dihydroxypyrimidine (ⅩⅠⅤ) maybe oxidized on the electrode. The height of the wave rises with increasing concent-rations of the pyrimidines and at the same concentration, the increase in acidityis accompanied by an increase of oxidation potential. In both cases, linear rela-tionships exist between the concentration and the height of the waves and betweenthe pH values and the half-wave potentials. 3. In alkaline solutions, no oxidation wave could be observed with 2-methyl-4, 5, 6-trihydroxypyrimidine (Ⅹ). 4. Various 5-hydroxypyrimidines possess different half-wave potentials. 5. Pyrimidines which have no hydroxy group at the 5-position, such as ura-cil, and those 5-hydroxypyrimidines with their hydroxy group protected, such as2-methyl 6 (4)-hydroxy-5-benzyloxypyrimidine, are not oxidized under the sameconditions. 6. The polarographic oxidation of 5-hydroxypyrimidines is discussed in con-nection with their structural characteristics.