2,6-二叔丁基-4-亚硝基苯酚的合成及表征

以2,6-二叔丁基苯酚、浓硫酸及亚硝酸钠为原料,在乙醇中合成了抗氧剂中间体2,6-二叔丁基-4-亚硝基苯酚,考察了溶剂种类、反应温度、反应时间、投料比和投料次序对反应的影响。结果表明,最佳工艺条件为：乙醇为溶剂,反应温度25℃,n（2,6-二叔丁基苯酚）∶n（浓硫酸）∶n（亚硝酸钠）=1∶1.1∶1.1,投料次序为先滴加浓硫酸,再滴加亚硝酸钠溶液,反应时间为2 h。在该条件下,产物重结晶收率为92.0%,产物色谱纯度≥99.7%。     

2,6-二叔丁基对硝基苯酚的合成与表征

以2,6-二叔丁基苯酚为原料,石油醚为溶剂,通过硝化反应合成了抗氧剂中间体2,6-二叔丁基对硝基苯酚,并采用元素分析和红外光谱对其结构进行表征。通过条件实验得出2,6-二叔丁基对硝基苯酚的最佳合成条件为:硝酸浓度为30%,反应原料摩尔比为1∶1.5,反应时间为10 h,此条件下,2,6-二叔丁基对硝基苯酚的产率为81.6%,熔点为156.9~157.8℃。     

2,6-二叔丁基-4-硝基苯酚的合成

以2,6-二叔丁基苯酚和硝酸为原料,合成了具有反应活性的抗氧剂中间体2,6-二叔丁基-4-硝基苯酚,并采用元素分析和红外光谱对其结构进行了表征.通过正交设计实验确定了抗氧剂中间体2,6-二叔丁基-4-硝基苯酚的最佳合成工艺,即反应原料硝酸的浓度为30%、2,6-二叔丁基苯酚与硝酸的物质的量比为1:1.5、反应时间为10 h、反应温度为30℃,在此最佳条件下得到产品的收率为81.7%,熔点为156.9～157.9℃.     

2,6-二叔丁基-4-氯甲基苯酚的合成和结构表征

以2,6-二叔丁基苯酚、多聚甲醛、氯化氢气体为原料,在冰乙酸溶剂中合成了2,6-二叔丁基-4-氯甲基苯酚,考察原料配比、反应温度、反应时间对产物收率的影响。结果表明,较佳的工艺条件为:在冰乙酸溶剂中,2,6-二叔丁基苯酚与多聚甲醛的摩尔比为1∶1.3,反应温度为30～40℃,反应时间为6 h。在上述条件下,2,6-二叔丁基-4-氯甲基苯酚的收率为84.7%,纯度可达96.8%。产物结构经红外光谱、核磁共振氢谱、核磁共振碳谱表征,与目标产物结构一致。     

抗氧剂4-羟甲基-2,6-二叔丁基苯酚的合成与应用

以2,6-二叔丁基苯酚和多聚甲醛为原料，在叔丁醇作溶剂的条件下合成了酚类抗氧剂4-羟甲基-2．6-二叔丁基苯酚，最佳反应条件为：反应时间4h，反应温度20℃，多聚甲醛与2，6-二叔丁基苯酚物质的量之比为2：1。催化剂用量为2，6一二叔丁基苯酚物质的量的3％，产品熔点在139-140℃，收率大于45％。介绍了产物作为中间体在其他抗氧剂合成中的应用。     

4,4'-亚甲基双(2,6-二叔丁基苯酚)的合成

研究了以2,6-二叔丁基苯酚为主要原料,与甲醛反应,在-定的条件下,合成4'4'-亚甲基双(2,6-二叔丁基苯酚)的方法.考察了投料比、溶剂的浓度、催化剂等因素对反应的影响.结果表明.在以氢氧化钠为催化剂的条件下,当乙醛与2,6-二叔丁基苯酚的摩尔比约为0.55.催化剂的量为0.5g左右.乙醇水溶液的深度为75%时,反...     

2,6-二氯-4-氨基苯酚的合成

[目的]制备新型农药氟啶脲和氟铃脲的高纯度中间体2,6-二氯-4-氨基苯酚。[方法]采用2,6-二氯苯酚为原料,在溶剂中硝化合成2,6-二氯-4-硝基苯酚,再在自制的催化剂存在下水合肼催化还原合成2,6-二氯-4-氨基苯酚,探讨合成过程的影响因素。[结果]实验确定了最佳反应条件,得到了纯度大于99.0%的目标产物。[结论]该工艺具有收率高、操作简单、安全可靠的特点,可为工业化生产提供参考。     

3,5-二叔丁基-4-羟基苯基丙酸甲酯的合成与工艺改进

3,5-二叔丁基-4-羟基苯基丙酸甲酯是一种抗氧剂,也是合成抗氧剂1076、抗氧剂1010等的主要原料。文章研究了合成3,5-二叔丁基-4-羟基苯基丙酸甲酯的工艺条件,对传统工艺条件进行了改进。传统合成方法采用NaOCH3作催化剂,产品收率(以2,6-二叔丁基苯酚计)75%～85%;文章采用KOH作催化剂,原料配比为:2,6-二叔丁基苯酚:丙烯酸甲酯=1:1.1,110°C下滴加丙烯酸甲酯,滴加时间1.5h,升温至130℃保温反应4h,用甲醇结晶,过滤,干燥得产品。产品收率(以2,6-二叔丁基苯酚计)95%。产品为白色晶体,熔点为63～65℃,符合文献值。     

4-叔丁基-2,6-二(4-吗啉甲基)苯酚的合成

在碱催化条件下,以对叔丁基酚为底物,与甲醛和吗啉进行Mannich反应,制备了4 叔丁基2, 6 二(4 吗啉甲基)苯酚。最佳工艺条件为: 80℃回流反应8h,w(NaOH) =10%的水溶液进行催化,收率83 8%。并通过红外光谱、核磁共振氢谱和碳谱对目标产物进行了结构表征。     

抗氧剂4,4'-乙撑二(2,6-二叔丁基苯酚)的合成研究

以甲醇钠为催化剂,采用2,6-二叔丁基苯酚、三聚乙醛为原料合成4,4’-乙撑二(2,6-二叔丁基苯酚),分别考察了反应温度、反应时间、原料配比、催化剂和溶剂用量等条件对缩合反应的影响。得到了合成4,4’-乙撑二(2,6-二叔丁基苯酚)最适宜的条件是:反应温度为125℃,反应时间8 h,n(2,6-二叔丁基苯酚)∶n(三聚乙醛)为0.2∶0.15;催化剂的用量为0.8 g、溶剂的用量为40 g(2,6-二叔丁基苯酚为0.2 mol的情况下)。4,4’-乙撑二(2,6-二叔丁基苯酚)的收率可达到91.75%以上,产品纯度w[4,4’-乙撑二(2,6-二叔丁基苯酚)]超过99.0%。     

Kinetics of the Reaction of 2,6-Di-tert-Butylphenol with Methyl Acrylate in the Presence of Potassium 2,6-Di-tert-Butylphenolate and the Effect of Proton Donor Components on the Reaction Mechanism

Abstract

The kinetic scheme of the reaction of 2,6-di-tert-butylphenol (ArOH) with methyl acrylate (MA) in the presence of potassium 2,6-di-tert-butylphenolate (ArOK) is proposed and elementary constants are calculated for the catalytic steps and the influence of proton donor components ArOH, H₂O and CH₃OH on kinetic regularities is studied. The kinetic scheme contains 30 components and involves 62 rate constants of elementary steps which were computed by the mathematical simulation method of process kinetics using a computer. The comparison was carried out for the computed and experimental data relating to the consumption rate dependence of ArOH on ArOK concentration and the concentration of proton donor components.     

2,6-二溴-4-三氟甲氧基苯胺合成的研究

研究了对三氟甲氧基苯胺溴代制备2,6-二溴-4-三氟甲氧基苯胺的各种工艺条件,考察了溶剂、反应温度、溴化试剂对反应的影响,并用IR、UV、1 H-NMR、ESI-MS对目标产物结构进行了表征,并用HPLC及UPLC检测了产品纯度。结果表明,在水溶剂中、70℃下使用液溴-双氧水作溴化试剂,收率可达97%以上,纯度达99.5%以上。经工艺优化将目标产品的原料成本从126 400元/t降至70 500元/t。     

2,6-二氯-4-三氟甲基苯胺制备新工艺

以对硝基甲苯为原料，经溴化、氟置换、加氢还原得4-三氟甲基苯胺，收率59．8％，纯度98．66％。然后，用硫酰氯作为氯化试剂，进行苯环上的氯化反应，制得氟虫腈关键中间体2,6-二氯-4-三氟甲基苯胺。收率83.9％，产品熔点34℃-35℃，纯度97．95％。对各步反应的影响因素进行了探讨。     

Studies on the Crystallization and Melting Behavior of Poly(ethylene 2,6-naphthalate)

Abstract

Crystallization behaviour of low molecular weight (oligomeric) and high molecular weight poly(ethylene 2,6-naphthalate)s (PEN) was studied using wide angle X-ray diffraction (WAXS) and differential scanning calorimetry (DSC). It was found that the crystallization conditions determine the nature of crystalline modification. Crystallization from the glassy state gives a-modification, whereas, crystallizing from the melt above 220°C results in β-modification. In contrast, the oligomers gives both the modifications up on crystallizing from the melt. The equilibrium melting temperatures of PEN were determined from DSC experiments, based on conditions of crystallization of a and β-modifications.     

2,6-萘二酚的提纯工艺研究

2,6-萘二酚粗品（纯度83.5%）在低级醇类、酯类单一溶剂或混合溶剂中重结晶,可以除掉杂质二聚物和2-萘酚等。较好的工艺条件为：m（活性炭）∶m（粗品）∶v（异丁醇）=0.1∶1∶3,回流搅拌30 min,过滤后滤液冷却得精制产品,纯度96.14%;m（活性炭）∶m（粗品）∶v（异丙醇）：v（水）=0.1∶1∶3∶9,纯度96.09%,收率68%,白色粉末状晶体。该工艺精制产品纯度高,经济环保,操作简便,易于工业化。     

Films of poly(4-azulen-1-yl-2,6-bis(2-thienyl)pyridine) for heavy metal ions complexation

Electrochemical behaviour and electropolymerization of 4-azulen-1-yl-2,6-bis(2-thienyl)pyridine (L) has been studied. Complexing polymer-coated electrodes have been synthesized by oxidative electropolymerization of L in acetonitrile solutions containing 0.1 M tetrabutylammonium perchlorate. The films were characterized by cyclic voltammetry, differential pulse-voltammetry and scanning electron microscopy. The complexing properties of L and these new polymer-coated electrode materials were investigated towards heavy metals leading to complexation of lead and cadmium metal cations inside the polymer film.     

尼泊金辛酯和异丙酯合成方法的研究

研究了各种因素对制备尼泊金辛酯，异丙酯产率的影响，筛选出最佳反应条件可使辛酯的收率达９６％，异丙酯的收率达８２％，用ＧＣ－ＭＳ计确定了异丙酯酯化应的副产物的结构，并提出了生成该副产物的反应机理。     

甲基异丁基酮分离过程中精馏-渗透汽化集成工艺的研究

对丙酮一步法生产甲基异丁基酮(MIBK)部分精馏流程进行了工艺分析,MIBK脱轻塔进料液中少量水的存在使MI-BK脱轻塔运行不稳定,进而影响MIBK合成液的整个分离过程。针对这个问题,提出了精馏-渗透汽化集成的工艺方案,省去MIBK脱轻塔。建立了渗透汽化小试实验,研究了NaA分子筛膜的渗透汽化过程以及分离性能。用Aspen Plus软件对精馏-渗透汽化集成工艺进行了模拟,与精馏过程相比,在MIBK产品质量与收率相同情况下,操作成本降低了20%,总成本可降低15%。     

Competent inhibitor for the corrosion of zinc in hydrochloric acid based on 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine

A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrode in 1.0 M HCl. The inhibition efficiency of BPEP was assessed through various techniques such as hydrogen evolution, galvanostatic polarization, potentiodynamic anodic polarization, and electrochemical impedance spectroscopy. The inhibiting action of BPEP was explained in terms of the formation of a stable complex between zinc ions and BPEP and then adsorbed onto the zinc surface. The formation of the complex was established by FT-IR spectroscopy. A conductometric titration indicated that the stoichiometry of Zn⁺²:BPEP (metal:ligand) is 1:1. The adsorption follows the Langmuir isotherm. The Galvanostatic polarization measurements have shown that the BPEP molecule acts as a mixed-type inhibitor. The pitting potential shifted in the noble direction, indicating that the inhibition of pitting corrosion of zinc in the presence of BPEP.The activation energy and themodyanamic parameters of the adsorption process were calculated and have been explained.