关键词: 2-羟基-4-(5, 6-二硝基-1H-苯并[2, 3-d]咪唑-2-基)苯甲酸甲酯, 4, 5-二硝基邻苯二胺, 羟基改性PBI纤维, 聚合, 合成, 纯化

Abstract: A novel compound，methyl 2-hydroxyl-4-(5,6-dinitro-1H-benzo[2,3-d]imidazole-2- yl)benzoate（MHDIB），was designed and synthesized from 4,5-dinitro-1,2-benzenediamine and methyl 2-hydroxy-4-carboxybenzoate.The one-pot synthesis method was adopted in synthesis of MHDIB . With 50mL diethylene glycol dimethyl ether as vehicle，methyl 2 - hydroxy-4-(chlorocarbonyl)benzoate was synthesized from 1.5 g methyl 2-hydroxy-4-carboxybenzoate and 2.5 g SOCl2 at 80 ℃，reaction time was 2 hours. At room temperature，1.56 g 4,5-Dinitro-o-phenylenediamine was added rapidly into the reaction system and 2 hours reaction time at 85 ℃. 3.52 g polyphosphoric acid was added and MHDIB was synthesized at reflux temperature for 1h。The preciptate formed was recrystallized with ethanol and yellow needles were obtained. Product yield was 17.82% and purity was 93.67%.The product was qualitatively exact and the structure was characterized by IR，ESI-MS，1H NMR. It was used to prepare a new AB-type monomer of high-performance polymer modified by orderly hydroxy ，poly 2-hydroxy-1,4-phenylene-2,6-benzo[2,3-d：5',6'-d'] diimidazole(H-PBI).

Key words: methyl 2-hydrox yl-4-(5,6-dinitro-1H-benzo[2,3-d]imidazole-2-yl)benzoate(MHDIB), 4,5-dinitro-1,2-benzenediamine, PBI fiber modified by hydroxy, polymerization, synthetic, purification