Abstract: 2-(4-aminophenyl)-1H-benzimidazol-5-amine (ABIA) was synthesized through condensation，reduction and cyclization reaction from 2,4-dinitrobenzenamine (DNBA) and 4-nitrobenzoyl chloride (NBC). The results showed that the optimum procedure of preparing the important intermediate N-(4’-nitrobenzoyl)-2,4-dinitro benzenamine (NDBA) by melt condensation at 170~180℃ could obtain NDBA with purity of 97% min. and yield of 68.40%. NDBA was reduced in HCl-aqueous solution by hydrogenation with catalyst of Pd/C to form N-(4’-aminobenzoyl)-2,4-diaminobenzenamine，and the product ABIA was obtained through the cyclization of ABTA under alkaline condition. Its purity can reach 99.5% min. (polymer monomer grade) by purification with yield of 64.87%. The structure of ABIA was identified by means of FT-IR，1HNMR and 13CNMR. The total yield was 44.37% based on NBC.

摘要： 以廉价的2,4-二硝基苯胺（DNBA）和对硝基苯甲酰氯(NBC)为原料，通过缩合、还原和环合反应制备了2-(4-氨基苯基)-1H-苯并咪唑-5-胺（ABIA）。研究结果表明：170～180 ℃下的熔融缩合是制备三硝基中间体N-(4’-硝基苯甲酰基)-2,4-二硝基苯胺（NDBA）的优选工艺，提纯后可获得纯度97%以上的NDBA，收率68.40%； NDBA在HCl-H2O溶液中先Pd/C催化加氢还原成N-(4’-氨基苯甲酰基)-2,4-二氨基苯胺（ADBA），再碱性环合反应，经乙醇-H2O重结晶后获得纯度99.5%以上的聚合级单体，收率为64.87%；经FT-IR、1H-NMR和13C-NMR定性为ABIA，以NBC计聚合级ABIA的总收率为44.37%。