Synthesis Of 2,4,9-Triazaadamantanes

Adamantanes are an important kind of cage compounds and widely used in synthesis of medicines, catalysts, functional materials and other areas. The purpose of this dissertation was to construct 2,4,9-triazaadamantane skeletons, then introduce several nitro groups to the cage to prepare polynitrotriazaadamantane.The synthetic route of 2,4,9-triazaadamantane was developed based on anhydrous citric acid. A important intermediate 3-(2-hydroxyethyl)-pentane-1,5-diol was successively synthesized via oxidative decarboxylation, condensation, reduction and hydrolysis. The attempt to oxidize it to corresponding trialdehyde derivative 3-oxoethyl-1,5-pentanedial then condense with primary amines to construct triazaadamantane skeleton failed because 3-oxoethyl-1,5-pentanedial was not obtained at all by several methods.The synthetic route of 2,4,9-triaza-7-adamantanol was then developed based on triallylmethanol. The attempt to synthesize 3-hydroxy-3-oxoethyl-1,5-pentanedial via ozonization and reduction from triallylmethanol, but 2,4,9-trioxa-7-adamantanol was obtained at last. It was used to react with primary amines but give no 2,4,9-triazaa-7-damantanol. However,2,4,9-trioxa-7-adamantanol could be nitrated to give corresponding nitrate derivative.The one-pot process of ozonization, reduction and condensation from triallylmethanol was successively carried out and afforded 2,4,9-tribenzyl-2,4,9-triaza-7-adamantanol, which was converted to a new energetic compound 2,4,9-trinitro-2,4,9-triazaadamantane-7-nitrate via debenzylization, acetylation and nitration with a total yield of 3.4%. The calculated results indicated that this compound exhibits high density (1.84 g·cm-3), excellent detonation velocity (8440 m·s-1) and detonation pressure (32.03 GPa). Its thermostability was investigated by thermogravimetric analysis and differential scanning calorimetry, and the TG-DSC curves show that it has good thermal stability, and exothermic reactions occur at the peak temperature of 198℃ and 259 ℃, which indicates that its thermal decomposition is a stepwise procedure.