高纯度AB型PBO新单体的合成新工艺研究

Study on novel technology for preparation of high-purity AB-PBO monomer

系统地研究了AB型PBO新单体:4-(5-氨基-6-羟基-2-苯并噁唑基)苯甲酸(ABA)的合成新工艺,考察了温度、反应时间、溶剂以及还原剂的用量对反应的影响.结果表明:采用以4-(5-硝基-6-羟基-2-苯并噁唑基)苯甲酸甲酯(MNB)为原料,经碳酸钾水解、连二亚硫酸钠还原—锅法合成高纯度ABA的新工艺,具有工艺简练、操作安全以及良好的经济性等特点,避开了原路线中昂贵的Pd/C催化剂和残留溶剂的阻聚效应,纯度达98%,总收率78.7%,精制后纯度达99%以上.最后经MASS和FT-IR等定性分析确认为ABA单体.

A novel synthesis technology of a new AB-PBO monomer. 4-（5-amino-6-hydroxybenzoxazole-2-yl）benzoic acid（ABA）is studied systematically. Effects of reaction temperature, time, solvent dosage and reducing agent dosage on ABA purity were investigated. The experimental, results showed that high-purity ABA was one-pot synthesized from methyl 4-（5- nitro-6-hydroxybenzoxazole-2-yl） benzoate （MNB） via K2CO3 hydrolysis and NaeS2O4 reduction with yield of 78. 7%, purity of 98% and above 99% after being refined, which had some advantages such as simple procedure, safe operation, low cost, expensive Pd/C catalyst avoidance and residues solvent-DMF avoidance. Finally, the ABA was identified by MASS and FT-IR.