出口前景广阔的液晶高分子中间体2，6酸

简要介绍了液晶高分子的优异性能及应用领域，根据国际通用的方法对液晶高分子进行了分类，对其中热致型液晶高分子合成所用中间体2，6酸国内外两种已工业化的生产路线进行了对比，介绍了国内先进的2，6酸合成工艺，并对2，6酸产品的出口前景进行了分析。     

1,6-二羟基-2-萘甲酸的合成研究

标题化合物是合成新型内分泌治疗剂的重要中间体,而其合成方法未见文献报道。以6-甲氧基-1-萘满酮为起始原料,经取代、氧化和水解3步反应得到目标产物,其结构经MS、~1HNMR、~(13)CNMR和IR确证。该路线原料廉价易得、操作简单、后处理方便,总收率达69.5%,适合工业化生产。     

6-甲氧基-1-萘甲酸的合成

采用AlCl3 作催化剂 ,以糠酸和苯甲醚为原料合成 6 -甲氧基 - 1-萘甲酸 ,产率可达6 7.7%     

溶剂法合成2-羟基-1-萘甲酸的工艺研究

以β-萘酚和氢氧化钠为原料,正辛烷为溶剂,合成了2-羟基-1-萘甲酸,纯度达98％以上。通过正交实验研究了反应压力、反应温度和反应时间对收率的影响,确定了最佳的工艺条件：反应压力0．8MPa,反应温度90℃,反应时间8h,该条件下收率达82．83％。     

2-羟基-3-萘甲酸生产工艺条件的优化研究

通过对中和及酸析过程的分析,采用改进后的参数指标进行中和及酸析得到的2-羟基-3-萘甲酸,产品为大颗粒、亮黄色,含量98.78%,收率80.13%(以消耗的2-萘酚计),并实现了在大生产中的应用。     

紫外区双波长光谱法测定2-羟基-3 萘甲酰基芳胺类色酚中2-羟基-3萘甲酸

取代苯作溶剂 ,用 0 .0 5%碳酸钠水溶液萃取工业品 AS类色酚中的 2 ,3-酸。在 p H值 1 0 .5～ 1 2 .0的碱性水溶液中 ,用紫外区双波长分光光度法测定 2 ,3-酸。回收率 98.6%～ 1 0 1 .2 % ,相对标准偏差 0 .86% ,检出限 0 .0 1 %。运用本方法对五种工业样品进行了测定     

溶剂法合成2-羟基-1-萘甲酸的工艺研究

以β-萘酚和氢氧化钠为原料,正辛烷为溶剂,合成了2-羟基-1-萘甲酸,纯度达98%以上。通过正交实验研究了反应压力、反应温度和反应时间对收率的影响,确定了优化的工艺条件:反应压力0.8 MPa,反应温度90℃,反应时间8 h,该条件下收率达82.83%。     

The structure of liquid crystalline aromatic copolyesters prepared from 4-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid

X-ray methods have been used to investigate the structure of liquid crystalline copolyesters prepared from 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA). Fibre diagrams and meridional diffractometer scans have been obtained for melt-spun specimens of five HBA/HNA ratios: $\text{25}\text{75}$, $\text{30}\text{70}$, $\text{50}\text{50}$, $\text{58}\text{42}$ and $\text{75}\text{25}$. The data indicate a high degree of axial orientation. The lateral packing is more irregular but the observation of some equatorial and off-equatorial Bragg reflections indicates the presence of some three-dimensional order. The patterns differ in the number and position of the meridional maxima, and these can be predicted accurately by a point model for aperiodic chains of totally random sequence. The sensitivity of the data to monomer ratio is illustrated by calculations across the range of composition from 100% HBA to 100% HNA.     

Electrocatalytic carboxylation of chloroacetonitrile at a silver cathode for the synthesis of cyanoacetic acid

The electrocatalytic carboxylation of chloroacetonitrile to cyanoacetic acid performed at silver cathodes was investigated both theoretically and experimentally. Silver exhibits powerful electrocatalytic activities towards the reduction of chloroacetonitrile. In CO₂-saturated CH₃CN, reduction of NCCH₂Cl occurs at potentials that are about 0.7 V more positive than those observed at glassy carbon and gives cyanoacetic acid in good yields. Theoretical considerations on the effect of operative parameters on the performances of the process were confirmed by electrocarboxylation experiments performed in undivided cells equipped with sacrificial anodes both in a bench-scale electrochemical batch reactor and in a continuous batch recirculation reaction system equipped with a parallel plate electrochemical cell. Selectivities and Faradic efficiencies higher than 80% were obtained by working under anhydrous conditions both under amperostatic and potentiostatic alimentation at proper values of either current density or applied potential.     

2-氯-6-氨基苯甲酸的合成

介绍了一种制备2-氯-6-氨基苯甲酸的新方法,即以2-氯-6-硝基甲苯为原料,经过铁粉还原,乙酸酐酰化保护,高锰酸钾氧化,氢氧化钠溶液水解,4步反应总收率61.5%。该法易于工业化放大,产品经重结晶纯度在95%以上,最终产品结构由FT-IR、1HNMR确定。     

硝酸法常压氧化制备2-氯-6-硝基苯甲酸

以2-氯-6-硝基甲苯为起始原料,在硫酸介质中,五氧化二矾催化下,滴加硝酸,常压氧化生成2-氯-6-硝基苯甲酸。     

Three-dimensional structure of copolymers of p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid: A model for diffraction from a nematic structure

X-ray methods have been used to investigate the three-dimensional structure of copolymers of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA). X-ray patterns of melt spun fibres indicate a high degree of axial orientation of the molecules, but with poor lateral order, except in some highly ordered regions. Our previous calculations have shown that the aperiodic meridional maxima are consistent with chains of completely random monomer sequence. Extension of these calculations to the three-dimensional structure has been done by calculating the cylindrically averaged intensity transform for single chains. The results point to a distorted hexagonal array of chains which have extended but otherwise random conformations, i.e. there is a broad distribution of aromatic-carboxyl torsion angles. It is suggested that in some regions the chain packing is more regular, perhaps due to axial register of HBA-rich sequences, giving rise to the off-equatorial reflections characteristic of three-dimensional order.     

6-溴-2-溴甲基-5-羟基-1-甲基吲哚-3-羧酸乙酯的合成工艺研究

采用5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯和溴素为原料,于四氯化碳中,在过氧化苯甲酰催化下,合成6-溴-2-溴甲基-5-羟基-1-甲基吲哚-3-羧酸乙酯,HPLC进行跟踪检测。采用正交设计研究确定了最佳合成工艺参数为:物料比1为n(5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯)∶n(四氯化碳)=1∶18.3,物料比2为n(5-乙酰氧基-1,2-二甲基吲哚-3-羧酸乙酯)∶n(溴素)=1∶2.84,反应时间5 h,反应温度45℃。在最佳条件下收率为84.6%,纯度为98%以上,达到了优化的目的。     

2,4,6–三甲基苯甲酸的合成

考察了在以均三甲苯为原料、CO2和AlCl3为酰化剂经Friedel-Crafts酰基化反应、水解合成2,4,6-三甲基苯甲酸工艺过程中,物料配比、反应温度等反应条件对收率的影响,确定了适宜的反应条件和后处理条件。通过此合成工艺,产品的产率可达83.3%。     

6-羟基-2-乙酰萘的制备

采用6 甲氧基 2 乙酰萘与浓盐酸在缚酸剂三乙胺存在的条件下进行水解反应制得6 羟基 2 乙酰萘。同时通过正交设计研究了反应的优化条件,即 6 甲氧基 2 乙酰萘、浓盐酸、三乙胺与二氯甲烷的比例为:1 g∶90 ml∶0.75 ml∶2.5 ml,反应收率为 79%。反应监控为TLC(展开剂为:正庚烷、二氯甲烷和丙酮=3∶6∶2.5,v/v)。盐酸的用量大幅度降低,产品成本降低36%。     

The structure of copoly(4-hydroxybenzoic acid/2-hydroxy-6-naphthoic acid): 2. An atomic model for the copolyester chain

X-ray fibre diagrams of fibres drawn from the (liquid crystalline) melts of copoly(4-hydroxybenzoic acid/2-hydroxy-6-naphthoic acid) show meridional maxima that are aperiodic. The positions of these maxima are reproduced in calculations of the meridional intensities for completely random copolymer sequences in which the monomers are approximated to points separated by the appropriate monomer lengths. These calculations have now been extended to consider an atomic model for the chains. Comparison of the calculated meridional transforms with diffractometer scans for five monomer ratios shows good agreement, not only for the positions but also for the relative intensities of the observed and calculated maxima. The linewidth of the maximum at d?2.1 ǎ depends on the chain length used for the calculations and presents a method for determination of the persistence length of the extended chain conformation.     

高效液相色谱外标法分析2-氨基-8-萘酚-6-磺酸中的有机杂质

摘要采用高效液相色谱法对2-氨基-8-萘酚-6-磺酸及其有机杂质进行分离,峰面积外标法进行定量分析。通过优化流动相的组成确定了样品分离条件,利用在线扫描确定了检测波长。使用甲醇和四丁基溴化胺溶液混合作为流动相,在检测器波长240nm处进行测定。     

肉豆蔻酸-2-羟基-3-磺酸钠丙酯的合成

以亚硫酸氢钠、环氧氯丙烷、磷酸钠和肉豆蔻酸等为原料,合成了肉豆蔻酸-2-羟基-3-磺酸钠丙酯,探索了反应温度、催化剂、反应时间、反应物物质的量比等因素对合成的影响。结果表明,适宜的反应条件为:①合成3-氯-2-羟基丙磺酸钠:环氧氯丙烷滴加到亚硫酸氢钠溶液中,反应时间3.5 h,反应温度85℃,②合成环氧丙磺酸钠:3-氯-2-羟基丙磺酸钠加入磷酸钠溶液中,反应温度55℃,反应时间4.0 h;③合成肉豆蔻酸-2-羟基-3-丙磺酸钠:环氧丙磺酸钠溶液滴加到90℃的肉豆蔻酸溶液中,反应时间3.0 h,产率为85.2%。对产品进行了红外光谱表征,产品显示了较好的表面活性。     

Electrocatalytic carboxylation of 2-amino-5-bromopyridine with CO2 in ionic liquid 1-butyl-3-methyllimidazoliumtetrafluoborate to 6-aminonicotinic acid

A new electrochemical procedure for the electrocatalytic carboxylation of 2-amino-5-bromopyridine with CO₂ in ionic liquid, 1-butyl-3-methyllimidazolium tetrafluoborate (BMIMBF₄), to 6-aminonicotinic acid was investigated for the first time. The experiments were carried out in three electrodes undivided cell under mild conditions, and the use of volatile and toxic solvents and catalysts, as well as any other additional supporting electrolytes, was avoided. The electrochemical reduction behavior of 2-amino-5-bromopyridine in BMIMBF₄ had been studied by cyclic voltammetry with a reduction peak at −1.6 V (vs. Ag). 6-Aminonicotinic acid was obtained in 75% yield and 100% selectivity, under the optimized condition. Moreover, the ionic liquid was successfully recycled.     

2-氨基-6-甲基苯甲酸的制备

以2-甲基-6-硝基苯胺为起始物,氨基重氮化后转化为氰基,然后氰基水解成羧基,最后以硫化钠作还原剂,将硝基还原成氨基得到2-氨基-6-甲基苯甲酸,总收率为38.1%。重氮化反应中2-甲基-6-硝基苯胺与盐酸的最佳摩尔比为1∶2.2,Sandmeyer氰化在室温反应3h后,升温至60°C反应30min收率最佳。