1974 年 32 巻 2 号 p. 130-135
In the reduction of nitro compounds with sodium sulfides, attention was given to the transfer of the vertices potential of sodium sulfides in the polarography, so the relationship between the vertices potential and the selectivity to amino compounds was studied. α-Nitronaphthalene (half wave potential of -0.80 V vs SCE) and 5, 8 -dichloro-1-nitronaphthalene (half wave potential of -1.41 V vs SCE) were used as model compounds for the reduction with sodium sulfides. And the reaction was followed using gas-chromatography and polarography. The analysis showed that the vertices potential of sodium sulfides was transfered to the negative side as the reaction proceed in each reduction, and they stopped in a slightly more negative position than each half wave potential of nitro compounds. On the other hand, the selectivity to amino compounds was improved as a resut of the transfer of vertices potential of sodium sulfides to the negative side. Reduction became quantitative after the vertices potential of sodium sulfides became more negative than that of nitro compounds, but the reduction rate became delayed. It was found that the vertices potential of sodium sulfides was related to the selectivity of amino compounds.