联苯-4,4'-二甲酸合成研究

研究联苯-4,4'-二甲酸的合成工艺,以对硝基甲苯为原料,经氧化、还原和重氮化-偶联反应制备联苯-4,4'-二甲酸.重点研究了重氮反应中滴加亚硝酸对反应的影响.以对硝基甲苯计,总收率为66.6%,联苯-4,4'-二甲酸的(HPLC)纯度为98.7%.     

4,4′-联苯二甲酸的合成研究

研究了4,4′-联苯二甲酸的合成工艺。以联苯为原料,经烷基化、水解反应制得4,4′-二(氨甲基)联苯盐酸盐,继而经Sommelet和氧化反应合成出4,4′-联苯二甲酸,总收率达到60.2%(以联苯计),纯度>98.0%,产物和中间体的结构经元素分析和核磁共振加以确证,对其反应条件进行了优化。工艺各步反应操作简单,原料易得,反应条件温和,具有一定的工业应用价值。     

4,4’-双(三氯甲基)联苯水解合成4,4’-联苯二甲酸工艺研究

以副产物4,4’-双(三氯甲基)联苯为原料,经碱性水解一步反应合成出4,4’-联苯二甲酸。考察反应物料摩尔比、反应温度、反应时间对4,4’-联苯二甲酸产品收率的影响,得到优化工艺条件:氯苯为溶剂,4,4’-双(三氯甲基)联苯与10%氢氧化钠溶液的摩尔比为1∶9,反应温度为105℃,反应时间为14 h。在上述条件下,4,4’-联苯二甲酸的收率为95.25%,纯度可达99.20%,通过红外光谱、核磁共振氢谱及高效液相色谱等对产物进行了表征。     

联苯-4,4′-二硫酚高效合成方法的研究

以联苯-4,4′-二磺酸钾为原料,先经五氯化磷酰化反应制备中间体联苯-4,4′-二磺酰氯,再经锡/盐酸还原得到目标产物联苯-4,4′-二硫酚。反应总收率55.25%,含量99.4%。该法经济环保、工艺简单,具有工业生产前景。     

3,3′-二羟基-4,4′-联苯二甲酸的合成和表征

联苯二甲酸类化合物是很好的刚性桥联配体,可用于制备纳米多孔材料.设计了一条制备联苯二甲酸类新配体的合成路线,以4-氨基水杨酸为原料,经过4步反应最终合成了新配体3,3′-二羟基-4,4′-联苯二甲酸,并通过红外光谱、核磁共振氢谱和元素分析进行了表征.     

超声辐射合成3,3-′二氯-偶氮苯-4,4-′二甲酰氯

以3,3′-二氯-4,4′-偶氮苯二甲酸为原料,氯化亚砜为酰基化剂,超声辐射快速合成3,3′-二氯-偶氮苯-4,4′-二甲酰氯。固定超声功率250W,较佳工艺条件为:3,3′-二氯-4,4′-偶氮苯二甲酸1.9g,氯化亚砜30mL,反应温度80℃,反应时间4h,收率达89.1%。产物结构经熔点仪、红外光谱、核磁共振和元素分析得到确认。     

合成4,4′-二硝基二苯乙烯-2,2′-二磺酸钠反应机理探讨

4,4-二硝基二苯乙烯-2,2′-二磺酸钠制备过程是对硝基甲苯邻磺酸氧化生成4,4 ′-二硝基二苯乙烷-2,2′-二磺酸钠;4,4′-二硝基二苯乙烷-2,2′-二磺酸钠再氧化生成4,4'-二硝基二苯乙烯-2,2′-二磺酸钠.通过对硝基甲苯邻磺酸次氯酸钠氧化合成4,4′-二硝基二苯乙烯-2,2′-二磺酸钠的反应实验,研究...     

2,7-二溴-N-苯基咔唑的合成

以4,4′-二溴联苯为原料,经硝化、闭环以及N-芳基化,3步反应合成目标产物2,7-二溴-N-苯基咔唑。硝化反应使用混酸作为硝化试剂,n(HNO_3)∶n(H_2SO_4)∶n(4,4′-二溴联苯)=1.3∶2.0∶1.0;闭环反应使用邻二氯苯为溶剂;N-芳基化反应使用碘化亚铜为催化剂。目标产物总收率53.7%。     

4,4‘-联苯二甲酸的合成研究

研究了4,4'-联苯二甲酸的合成工艺.以联苯为原料,经烷基化、水解反应制得4,4'-二(氨甲基)联苯盐酸盐,继而经Sommelet和氧化反应合成出4,4'-联苯二甲酸,总收率达到60.2%(以联苯计),纯度＞98.0%,产物和中间体的结构经元素分析和核磁共振加以确证,对其反应条件进行了优化.工艺各步反应操作简单,原料易得,反应条件温和,具有一定的工业应用价值.     

羟基改性聚对亚苯基苯并二唑单体3,3′-二氨基-4,4′-二羟基联苯盐酸盐的合成

为改进聚对亚苯基苯并二唑（PBO）纤维复合黏结性能差等缺点,在苯环上引入极性基团羟基进行化学分子结构改性,3,3′-二氨基-4,4′-二羟基联苯盐酸盐（DADHBP·2HCl）是羟基改性PBO的关键单体。以4,4′-二羟基联苯（DHBP）为原料经硝化、还原反应合成得到中间体3,3′-二硝基-4,4′-二羟基联苯（DNDHBP）和羟基改性PBO的单体DADHBP·2HCl,并对其反应条件进行了优化。结果表明：对于硝化反应,以甲苯、冰乙酸的混合液为反应溶剂,n(DHBP)∶n(HNO₃)=1∶2,反应温度5℃,反应时间2.5h,收率81.39％,高效液相色谱（HPLC）纯度(质量分数)92.43％;还原反应,n(DNDHBP)∶n(FeSO₄·7H₂O)=1∶9,乙醇为溶剂,七水合硫酸亚铁为助剂,n(DNDHBP)∶n(N₂H₄·H₂O)=1∶5.5,反应温度78℃,反应时间9h,热过滤,滤饼盐酸精制后得到DADHBP·2HCl,收率67.16%,HPLC纯度（质量分数）98.20%。中间体和产物结构经红外光谱、核磁氢谱和电喷雾质谱表征确认。     

联苯二甲酸共聚改性PET的合成及热性能研究

以4,4′-联苯二甲酸(BPDA)、对苯二甲酸和乙二醇为单体采用直接酯化法工艺制备了不同BPDA含量的共聚酯;借助核磁共振氢谱表征了共聚酯的组成;利用差示扫描量热法和热重分析法研究了共聚酯的热性能。结果表明:共聚酯的组成符合理论预期值,其粘均相对分子质量为26 400～27 600;随着BPDA含量的增加,共聚酯的结晶能力先增强后减弱,而玻璃化转变温度和热分解温度都有所提高。     

2，2＇-二羟基-1，1-联萘-4，4＇-二羧酸的合成

BINOL类配体是一类重要的具有C2轴、不含手性中心的不对称联芳香化合物。文章将3-硝基-1-萘酸用亚硫酸铁还原成胺,并生成稳定的硫酸盐,之后重氮化,用沸腾的稀硫酸水解成酚,再成酯,最后用三氯化铁在水中偶联合成化合物2,2’-二羟基-1,1＇-联二萘-4,4’-二羧酸。并探讨了各反应过程中的影响因素。     

Poly(P-benzoquinono)diimidazoles from two-ring aromatic dicarboxylic acids

New poly(p-benzoquinono)diimidazoles have been synthesized by one-stage polycondensation in polyphosphoric acid of 2,3,5,6-tetraamino-p-benzoquinone with diphenyl-4,4′-dicarboxylic acid, diphenylmethane-4,4′-dicarboxylic acid, 4,4′-oxydibenzoic acid, and 4,4′-sulfonyldibenzoic acid. The polymers were characterized by infrared and ultraviolet spectral study, viscometric measurements, and thermal analysis. The effects of introducing flexibilizing links such as ? CH₂? ,? O? , and ? SO₂? in the backbone of the polymers, on their thermal stability and solubility were studied.     

Copolyimides new polybenzoxazinone-imides

New polybenzoxazinone-imides have been synthesized by cyclopolycondensation reaction of 4,4′-diaminodiphenylmethane-3,3′-dicarboxylic acid with diacid chlorides containing preformed imide rings. The low temperature solution polycondensation technique, used in these experiments, afforded poly(amic acids) of high molecular weight in the first step, which subsequently underwent thermal cyclodehydration at 200–300°C to give polybenzoxazinone-imides in the second step. The obtained polymers have been characterized by IR absorption, elemental and thermogravimetric analyses. From 10% polymer solution flexible and transparent films have been cast with good mechanical and insulating properties.     

Liquid crystalline aromatic polyesters containing para-linked dimethylbiphenylene moieties

A series of liquid crystalline aromatic polyesters containing 3,3′-dimethylbiphenyl-4,4′-dicarboxylic acid and 3,4′-dimethyl-biphenyl-4,3′-dicarboxylic acid was prepared by a melt polycondensation procedure and characterized by elemental analysis, DSC and TMA measurements, and optical polarizing microscopy. An optimal composition of the copolymer having a melting temperature around 300°C is proposed and the rheological behavior is discussed. Most of the mechanical properties of this copolymer were found to be close to those of Vectra A950® used as a reference sample. © 1996 John Wiley & Sons, Inc.     

Thermal degradation of polymers. Part XVIII. The synthesis and characterization of quinazolone pre-polymers

A series of quinazolone pre-polymers have been prepared from 4,4′-diaminodiphenyl-3,3′-dicarboxylic acid and aromatic diacetamido compounds by melt polycondensation. The pre-polymers have been characterized by combustion analysis, viscometry, vapor pressure osmometry, and thermal analytical methods (TG, DTA, and DSC). Structures have been elucidated by spectroscopic methods (IR and NMR). The thermal cyclization of these pre-polymers to the partial ladder polyquinazolone has been studied and optimized using IR, DSC/DTA, TG, and evolved gas analysis. The cyclization behavior of these systems has been resolved in terms of concurrent dehydration and decarboxylation.     

Pd/C催化加氢法制备DSD酸

用水作反应介质,Pd/C为催化剂,研究了液相催化加氢法还原4,4′ 二硝基二苯乙烯 2,2′ 二磺酸(DNS)制备4,4′ 二氨基二苯乙烯 2,2′ 二磺酸(DSD酸)。通过一系列条件实验,确定的最佳工艺条件是:原料DNS10g,质量浓度为180g/L;Pd/C催化剂0 8g;助催化剂OVN80mg;反应体系pH=6;反应温度65℃;压力0 8MPa。在此工艺条件下,制得产品的质量分数大于99%,产品收率可达95%。     

Preparation of polyamides containing para-linked dimethylbiphenylene moieties

A series of wholly aromatic polyamides containing 3,3′-dimethylbiphenyl-4,4′-dicarboxylic acid (P-DMBA) and 3,4′-dimethylbiphenyl-4,3′-dicarboxylic acid (Q-DMBA) was prepared by the direct polycondensation method using triphenylphosphite and pyridine. Most of the polymers are readily soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP), N,N′-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), pyridine (py), and m-cresol and could be cast into tough and flexible films. The solubilities of copolyamides containing P-DMBA and Q-DMBA as acid components were remarkably improved. These were characterized by inherent viscosity, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical spectrometry (DMS) measurements. The glass transition temperatures of these polymers were in the range of 200–300°C and the 5% weight loss temperatures were 430–470°C. Films prepared by casting from polymer solutions exhibited good tensile properties. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:847–853, 1998     

3,3'-二叔丁基-4,4'-二氨基二苯甲烷的合成

以4,4'-二氨基二苯甲烷为原料,通过乙酰化反应、烷基化反应、去乙酰化反应,合成了3,3'-二叔丁基-4,4'-二氨基二苯甲烷,采用FTIR证实了其分子结构。通过产率测定研究了各反应阶段的影响因素,确定最佳反应条件:乙酰化反应中,在反应温度215℃下,乙酸过量200%,产率达97%;烷基化反应中,以N,N'-二甲基甲酰胺(DMF)为溶剂,无水三氯化铝为催化剂,在25℃反应温度下,产率达92%;去乙酰化反应中,采用浓盐酸加热,冰浴析出法,产率达98%。通过向4,4'-二氨基二苯甲烷的苯环上引入大体积的叔丁基,提高双马来酰亚胺树脂单体在普通溶剂中的溶解能力,降低预聚体粘度,以便于双马来酰亚胺树脂应用传递模塑成型工艺(RTM)加工。