Studies On Synthesis Of Trifurazano-Azepine Derivatives

3,4-bis (4’-nitrofurazan-3’-yl)furoxan (BNFF) is consist of furazan, furoxan and nitro, its overall performance is very good, and it’s the key raw material to develop a high-performance Energetic Materials.In this paper, BNFF was prepared from malononitrile by four-step reaction, the mechanism of four-step reactions was investigated. The effect of the different oxidation system, which was composed by different concentrations of H2O2 with Na2WO4,98% H2SO4, (CF3CO)2O, on yield of BNFF was discussed.Used BNFF as the raw material, nine different substitutions of 7H-difurazano [3,4-b:3’,4’,f]furoxano[3",4",d]azepine were synthesized by reacted with different primary amines. The mechanism and selectivity of SN2 nucleophilic substitution reaction of BNFF and primary amines were discussed. The effects of reaction temperature, reaction time and materials ratio were discussed, to obtain the optimum cyclization conditions:the molar ratio of BNFF and primary amine was 1:3, feeding temperature was 0～5℃, the reaction mixture was stirred at the low temperature for 1h, then reacted at 40℃ for 35min.N-(2’,4’-dinitrophenyl)-2-aminoethyl-7-H-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d]azepi ne, N-(2’,4’,6’-trinitro-3’-aminophenyl)-2-aminoethyl-7-H-difurazano[3,4-b:3’,4’,f]furoxano[3", 4",d]azepine were prepared by the reaction of 7-(2-amino-l-ethyl)-difurazano[3,4-b:3’,4’,f] furoxano[3",4",d]azepine with 2,4-dinitro-chlorobenzene and 2,4,6-trinitro-3-amino-chloro-benzene. The effects of reaction solvent, temperature and the species and dosage of acid-binding agent were discussed, to obtain the optimum conditions:optimum reaction solvent was acetonitrile, reaction temperature was 80℃, the acid-binding agent was sodium carbonate, and the dosage was 1.5g.N-(2’-nitrophenylmethylene)-7H-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d]azepine, N-(3’-nitrophenylmethylene)-7H-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d]azepine, N-(4’-nitropheny 1-methylene)-7H-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d]azepine were prepared by the reaction of 7-amino-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d] azepine with o-, m-,p-nitro benzaldehyde. The effects of reaction temperature, the species and dosage of acid catalyst were discussed, to obtain the optimum conditions:the reaction temperature was 80℃, the optimum acid catalyst was acetic acid, and the dosage was 0.6mL (1 equiv).All target compounds were characterized by 1H NMR,13C NMR, IR and MS. The geometry, heats of formations(HOFs) and detonation performance of the above mentioned nine 7H-difurazano[3,4-b:3’,4’,f]furoxano[3",4",d]azepine derivatives were calculated, to guide the experimental results. Meanwhile, the detonation performance parameters of five kinds of N-nitrobenzene-7H-azepine were estimated.