Study For The Hydrogenation Process Of Octanedinitrile To Diaminooctane

Diaminooctane is an important chemical raw materials, it is widely used in medicine, engineering plastics, detergents and other fields. It can be modified DNA. It can inhibit transcription of HIV-1 replication of the virus. Besides, Diaminooctane is processed into resin, fiber and a variety of engineering plastics products. Recently, with the development of the technology, Diaminooctane has been more and more widely used.There were a few studies about the hydrogenation process of octanedinitrile to diaminooctane and the catalysts of this reaction at present. These studies were basically to maintain the traditional synthesis process. In this article, 1,8-Diaminooctane was prepared from octanedinitrile via the hydrogenation process. The solvents and catalysts were screened. The results showed that the best solvents and catalysts were Raney nickel and ethanol. The single factor experiments were designed. Factors affecting reaction selectivity and yield rate were investigated. These factors were the amount of sodium hydroxide, the reaction temperature, the reaction pressure and the initial reactant concentration. After the reaction, the optimal process conditions were obtained as follows:temperature 80℃, NaOH amount 1%(m/m, based on Octanedinitrile), pressure 1.5-2.5MPa, Octanedinitrile amount 1:15(v/v, based on ethanol). The reaction selectivity could be 100% and the yield rate could be above 99.8%.The reaction mechanism of the hydrogenation process of octanedinitrile to diaminooctane was not investigated. After the sample of the reaction process was analyzed by gas chromatography, the result showed that there was an intermediate product. The intermediate product was isolated and purified, and then it was analyzed by GC-MS, 1H-NMR spectrometer and 13C- NMR spectrometer. It was identified as 8-aminosuberic nitrile. The reaction mechanism of the hydrogenation process of octanedinitrile to diaminooctane could be inferred that the hydrogenation process of octanedinitrile to diaminooctane was completed in two stages. The first phase is to generate 8-aminosuberic nitrile. The second phase is to generate diaminooctane.