AB型羟基改性PBO单体及其合成新技术

提出单羟基改性PBO及其AB型单体的分子结构,研究了以4-氨基-6-硝基间苯二酚盐酸盐(ANR·HCl)和羟基对苯二甲酸(HTA)为原料直接缩环合制备2-羟基-4-(5-硝基-6-羟基苯并 唑-2-基)苯甲酸(HNBA)、再还原合成AB型单体:2-羟基-4-(5-氨基-6-羟基苯并 唑-2-基)苯甲酸(HABA)的新方法。结果表明:缩环合制备的HNBA,其纯度96.81%、收率69.25%;进一步还原合成出纯度>98%的单体HABA,以ANR·HCl计的总收率为58.38%;具有原料易得、步骤短、条件缓和、产物稳定性优异以及缩聚基团完全等当比等性质。合成的新单体HABA及其前体HNBA,经FT-IR和MS以及NMR等分析和表征,证实了其分子结构。

AB monomers of hydroxy modified PBO and its novel synthesis technology

The molecular structure of a monohydroxy modified PBO and its AB monomer were proposed, and 2-hydroxy-4-(5-amino-6-hydroxybenzoxazole-2-yl) benzoic acid(HABA)was synthesized by the condensation-cyclization reaction of 4-amino-6-nitroresorcinol hydrochloride(ANR·HCl)and hydroxy terephthalic acid(HTA), then 2-hydroxy-4-(5-nitro-6-hydroxybenzoxazole-2-yl) benzoic acid(HNBA)was reduced to obtain the AB monomer (HABA). The precursor HNBA was one-pot prepared from ANR·HCl and HTA with a yield of 69.25% and purity of 96.81%, and the AB monomer HABA with a purity >98% was obtained by reducing HNBA, with a total yield of 58.38% from ANR·HCl. The novel synthesis technology had the characteristics of convenient source of raw materials,short reaction steps,mild conditions,excellent stability and equi-molar polycondensing group. HABA and HNBA were identified with FT-IR, MS and NMR.