间接电还原制备4-氯-3，5-二氨基苯甲腈

采用间接电化学还原路线，在离子膜电解槽中，以铜板作阴极电极，石墨作阳极电极，电流密度50mA／cm^2，将Sn^4＋还原为Sn^2＋，然后用该电解液还原4-氯-3，5-二硝基苯甲腈为4-氯-3,5-二氨基苯甲腈。实验结果表明，盐酸浓度为4mol／mL。反应温度20℃，Sn^2＋与4-氯-3，5-二硝基苯甲腈的物质的量之比为6．6／1有最佳的反应效果。母液循环试验5次，平均产率88．1％。平均电解效率74．2％。

Preparation of 4-Chloro-3,5-diaminobenzonitrile by Indirect Electroreduction Method

4 -Chloro- 3,5 -diaminobenzonitrile was prepared by indirect electrochemistry reduction. At first, Sn^4＋ was reduced to Sn^2＋ in ionic membrane electrolytic cell using the copper plate as negative electrode and the graphite as anode electrode, and the current density was 50mA/cm^2, then, 4 - ehloro - 3,5 - dinitrobenzonitrile was reduced to the product by the electrolyte. The optimum react conditions were given in this paper. The concentration of HCl was 4.0 mol/L, and the react temperature was 20℃, and the molar ratio of Sn^2＋ and 4 - chloro - 3,5 - dinitrobenzonitrile was 6.6/1. The recycle use of the mediator was also studied and the average yield of product was 88.1%. and the average current efficiency was 74.2%.