Chemical Industry and Engineering Progress ›› 2019, Vol. 38 ›› Issue (02): 1062-1067.DOI: 10.16085/j.issn.1000-6613.2018-0959

• Fine chemicals • Previous Articles     Next Articles

Synthesis of 4-(6-hydroxy-5-nitro-2-benzoxazolyl)-2,6-dihydroxybenzoic acid

DONG Bin, FU Cong, WU Chunxin, ZHANG Jianting, JIN Ningren, ZHAO Deming   

  1. College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
  • Received:2018-05-09 Revised:2018-09-17 Online:2019-02-05 Published:2019-02-05

4-(6-羟基-5-硝基-2-苯并唑基)-2,6-二羟基苯甲酸的合成

董斌, 付聪, 吴纯鑫, 张建庭, 金宁人, 赵德明   

  1. 浙江工业大学化学工程学院, 浙江 杭州 310014
  • 通讯作者: 赵德明,博士,副教授。
  • 作者简介:董斌(1992-),男,硕士研究生,研究方向为有机合成。
  • 基金资助:
    江苏省重大科技计划支撑项目(BE2011129);浙江省教育厅项目(Y201121211)。

Abstract: The intermediate 4-[(2,4-dihydroxy-5-nitrophenyl)carbamoyl]-2,6-dihydroxy-benzoic acid (2,6-DH-NCA) and a key precursor of AB-type acid new monomer of 2,6-dihydroxyl modified PBO 4-(6-hydroxy-5-nitro-2-benzoxazolyl)-2,6-dihydroxybenzoic acid (2,6-DH-NBA) were successfully synthesized through a series of reactions, including one pot reaction of the acylchlorination and Nacylation, and the dehydration cyclization reaction by using 2,6-dihydroxyterephthalic acid (2,6-DH-TA) and 4-amino-6-nitroresorcinol hydrochloride (ANR·HCl) as materials. The optimal experimental conditions of one pot reaction of acylchlorination and N-acylation and the dehydration cyclization were obtained. For the one pot reaction of acylchlorination and N-acylation, with the 1, 4-dioxane as acylchlorination solvent and SOCl2 as acylchlorination reagent, the acylchlorination time was 2h; with the triethylamine as the deacid reagent of N-acylation, the temperature of N-acylation at 105℃ and the reaction time was 4h, n(2,6-DH-TA):n(ANR·HCl):n(SOCl2):n(triethylamine) was 1.0:1.0:2.0:0.5, the yield of 2,6-DH-NCA was 80.31% and the purity was 98.57% as determined by HPLC. For the dehydration cyclization reaction, with the diethylene glycol dimethyl ether as solvent and the polyphosphoric acid(PPA) as dehydrant, and the content of P2O5 in PPA of 85%, the reaction temperature at 135℃, the reaction time was 6h, w(2,6-DH-NCA):w(PPA) was 1:8.6, the yield of 2,6-DH-NBA was 83.76%, and the purity was 99.25% as determined by HPLC.

Key words: 2,6-dihydroxyterephthalic acid, 4-(6-hydroxy-5-nitro-2-benzoxazolyl)-2,6-dihydroxybenzoic acid, cyclization, one pot reaction

摘要: 研究了以2,6-二羟基对苯二甲酸(2,6-DH-TA)与4-氨基-6-硝基间苯二酚盐酸盐(ANR·HCl)为原料经酰氯化和N-酰化一锅法及环合等一系列反应合成得到中间体4-[(2,4-二羟基-5-硝基苯基)氨甲酰基]-2,6-二羟基苯甲酸(2,6-DH-NCA)和2,6-二羟基改性PBO的AB型酸类新单体的关键前体4-(6-羟基-5-硝基-2-苯并唑基)-2,6-二羟基苯甲酸(2,6-DH-NBA),并对其反应条件进行了优化。结果表明:对于酰氯化和N-酰化一锅法反应,以1,4-二氧六环为酰氯化溶剂,SOCl2为酰氯化试剂,酰氯化时间2h,N-酰化溶剂为4-甲基2-戊酮,N-酰化温度105℃,N-酰化时间4h,N-酰化缚酸剂为三乙胺,n(2,6-DH-TA):n(ANR·HCl):n(SOCl2):n(三乙胺)=1.0:1.0:2.0:0.5,经乙醇精制,2,6-DH-NCA收率80.31%,HPLC纯度(质量分数)98.57%;环合反应,以二乙二醇二甲醚为溶剂,多聚磷酸(PPA)为脱水剂,PPA中P2O5质量含量85%,w(2,6-DH-NCA):w(PPA)=1:8.6,反应温度135℃,反应时间6h,2,6-DH-NBA收率83.76%,HPLC纯度99.25%。中间体和产物结构经FTIR、1H NMR和EI-MS表征确认。

关键词: 2,6-二羟基对苯二甲酸, 4-(6-羟基-5-硝基-2-苯并唑基)-2,6-二羟基苯甲酸, 环合反应, 一锅法

CLC Number: 

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