Study On Synthesis Of Several Nitropyridine Compounds

Polynitropyridines are important energetic Materials.4-nitropyridine-N-oxide was prepared at first from pyridine by oxidation and nitration.4-amino-3,5-dinitropyridine was synthesized from 4-nitropyridine-N-oxide by reduction and dinitration.4-amino-3, 5-dinitro-2-pyridone was obtained from oxidation of 4-amino-3,5-dinitropyridine.These two compound were intermediates of insensitive explosive.The mechanism of related unit process was described.The factors of reaction conditions such as mole ratio between materials, reaction time and temperature were studied.Optimum conditions of deoxidation dinitration were obtained as follows:the volume ratio of fuming nitric acid and concentrated sulfuric acid was 1:4.The molar ratio of nitric acid and 4-aminopyridine was 3:1,reaction 0.5h under room temperature and 1h under 85℃, the yield was 61%.Optimum conditions of producing 4-amino-3,5-dinitro-2-pyridone were obtained as follows:the molar ratio of hydrogen peroxide and 4-amino-3,5-dinitropyridine was 7.5:1,the volume ratio of 30%oxydol and acetic acid was 4.5:1,reaction 5h under room temperature, the yield was 60%.The structure of compounds were determined by IR,GC-MS,LC-MS and HNMR spectra.