Synthesis
(1) Using m-dichlorobenzene as raw material, dropwise addition at low temperature and high temperature nitration in a mixed acid system of concentrated sulfuric acid and fuming nitric acid to obtain 1,3-dichloro-4,6-dinitrobenzene;
(2) 1 ,3-Dichloro-4,6-dinitrobenzene is placed in a high-pressure reactor in the presence of ammonia water, and the temperature is raised to 145～150 ℃ for ammonolysis reaction to obtain 4,6-dinitro-1,3-benzenediol Amine;
(3) Place 4,6-dinitro-1,3-phenylenediamine, oxygen-free distilled water and palladium-carbon catalyst in a hydrogenation autoclave, and catalyze it under a hydrogen atmosphere of 1-1.5MPa and 85°C After the hydrogenation reaction, the catalyst was removed by hot filtration under nitrogen protection to obtain a 1,2,4-triaminobenzene hydrochloric acid solution;
(4) take the 1,2,4,5-tetraaminobenzene obtained in step (3) The solution was added with concentrated hydrochloric acid, cooled to room temperature, filtered under nitrogen protection, and the filter cake was dried in a vacuum desiccator at 40°C to obtain 1,2,4-triaminobenzene hydrochloric acid.
The molar ratio of m-dichlorobenzene to fuming nitric acid described in the step (1) is 2.2:1, the mass ratio of concentrated sulfuric acid to fuming nitric acid is 3:8～10, and the dropping temperature is -5～0°C, The nitration temperature is 100-104°C.
The reaction time of the ammonolysis described in step (2) is 3.5～4h, and the molar ratio of 1,3-dichloro-4,6-dinitrobenzene to ammonia water is 1:(10～14).
The oxygen-free distilled water described in step (3) is distilled water purified by nitrogen, and the reaction time of catalytic hydrogenation is 3-4h; 4,6-dinitro-1,3-phenylenediamine, palladium-carbon catalyst and oxygen-free The mass ratio of the three distilled water is 1:0.05:10.
The volume ratio of the 1,2,4-triaminobenzene hydrochloric acid solution described in step (4) to concentrated hydrochloric acid is 1:0.2-0.3.
