Synthesis Of Azobenzene Nitroderivatives

New high-energy density heat-resistant explosives are an important research direction for energetic materials.The azobenzene polynitroderivative has a large conjugated system and contains a plurality of nitro groups and oxidized azo groups,so that it has excellent heat resistance and explosive properties.Therefore,it is of important practical value to study the synthesis process and performance of azobenzene nitroderivatives.The final product three azobenzene nitroderivatives were synthesized by nitration the intermediate 1,2-bis(4-chlorophenyl)diazene which was prepared from 4-chloroaniline by oxidation.And the structures are determined by melting point,infrared spectrum,elemental analysis,single crystal diffraction,nuclear magnetic resonance,and mass spectrometry The effects of various process parameters on the reaction were studied,and the optimal synthesis conditions were obtained.The thermal properties of three azobenzene nitro derivatives were studied by DSC.1,2-bis(4-chlorophenyl)diazene was synthesized by oxidation of manganese dioxide with 4-chloroaniline as the material.The synthesis of 1,2-bis(4-chlorophenyl)diazene was optimized by singe factor experiments.The results show that the best experimental condition were: the molar ratio of 4-chloroaniline to manganese dioxide was 1:5,reaction time was 6 h,reaction temperature was 110 ℃,the best production yield was 60.94%.2-(4-chloro-2,6-dinitrophenyl)-1-(4-chlorophenyl)diazene oxide was synthesized by nitration of fuming nitric acid with 1,2-bis(4-chlorophenyl)diazene as the starting material.The synthesis of 2-(4-chloro-2,6-dinitrophenyl)-1-(4-chlorophenyl)diazene was optimized by singe factor experiments.The results show that the best experimental condition were: the molar ratio of 1,2-bis(4-chlorophenyl)diazene to fuming nitric acid was 1:16,reaction time was 4 h,reaction temperature was 85 ℃,the crude yield was 61.67%.2-(4-chloro-2,6-dinitrophenyl)-1-(4-chloro-3-nitrophenyl)diazene oxide was synthesized by fuming nitric acid with 1,2-bis(4-chlorophenyl)diazene as the starting material.The synthesis of 2-(4-chloro-2,6-dinitrophenyl)-1-(4-chloro-3-nitrophenyl)-diazene oxide was optimized by singe factor experiments.The results show that the best experimental condition were:the molar ratio of 1,2-bis(4-chlorophenyl)diazene to fuming nitric acid was 1:64,molar ratio of nitric acid to sulfuric acid was 1:1.5 reaction time was 5 h,reaction temperature was 90 ℃,the best production yield was 94.92%.2-(4-chloro-2,6-dinitrophenyl)-1-(4-chloro-3,5-dinitrophenyl)diazene oxide was synthesized by sulfuric acid and fuming nitric mixed acid with 1,2-bis(4-chlorophenyl)-diazene as the starting material.The synthesis of 2-(4-chloro-2,6-dinitrophenyl)-1-(4-chloro-3,5-dinitrophenyl)diazene oxide was optimized by singe factor experiments.The results show that the best experimental condition were:the molar ratio of 1,2-bis(4-chlorophenyl)diazene to fuming nitric acid was 1:80,molar ratio of nitric acid to sulfuric acid was 1:6 reaction time was 5 h,reaction temperature was 120 ℃,the best production yield was 17.98%.The thermal stability of three azobenzene nitroderivatives were analyzed by differential scanning calorimetry(DSC).