The synthesis and characterization of oligo-N-4-aminopyridine, oligo-2-[(pyridine-4-yl-imino) methyl] phenol and its some oligomer-metal complexes

The product and the oxidative polycondensation reaction conditions of oligo-4-aminopyridine were studied by using NaOCl as oxidant. Oligo-4-aminopyridine (4-OAP) was synthesized from the oxidative polycondensation of 4-aminopyridine (4-AP) in an aqueous solution medium acidic and neutral between 25 and 60 °C by using NaOCl as oxidant. About 85% of 4-AP was converted to 4-OAP. The number average molecular weight, (M_n) mass average molecular weight (M_w) and polydispersity index (PDI) values of 4-OAP synthesized were found to be 270, 850 g mol⁻¹ and 3.15, respectively, using NaOCl. The respective values of the Schiff base were 1721, 2256 g mol⁻¹ and 1.31, respectively, using air oxygen and 2173, 2372 g mol⁻¹ and 1.09, respectively, using NaOCl and 2749, 6432 g mol⁻¹ and 2.33, respectively, using H₂O₂. At the optimum reaction conditions, the yield of oligo-2-[(pyridine-4-yl-imino) methyl] phenol (OPMP) were found to be 86% (H₂O₂) and 89% (NaOCl) and 95% (air oxygen). The 4-OAP and OPMP were characterized by ¹H NMR, FT-IR, UV-Vis and elemental analysis. TG analysis showed to be stable of 4-OAP against thermo-oxidative decomposition. The weight loss of 4-OAP and its Schiff base oligomer was found to be 50, 86.39 and 71.78% at 525, 625 and 1000 °C, respectively. Also, new oligomeric Schiff base was synthesized from condensation of 4-AP with salicylaldehyde and their structures and properties were determined. During polycondensation reaction, a part of the azomethine (-CHN-) groups oxidized to carboxylic (-COOH) group. Thus, soluble fraction in water of oligo-2-[(pyridine-4-yl-imino) methyl] phenol involved in carboxylic (-COOH) (11%) group. Besides, the structure and properties of oligomer-metal complexes of oligo-2-[(pyridine-4-yl-imino) methyl] phenol (OPMP) with Cu(II), Ni(II) and Co(II) were studied.     

UV–944对聚酰胺6抗紫外光老化和热氧稳定性的影响

在己内酰胺开环水解过程中,加入一定量的聚{[6-[(1,1,3,3-四甲基丁基)氨基]]-1,3,5-三嗪-2,4-[(2,2,6,6-四甲基-哌啶基)亚氨基]-1,6-己二撑[(2,2,6,6-四甲基-4-哌啶基)亚氨基]}(UV–944),合成改性聚酰胺6。研究了UV–944对聚酰胺6光稳定性、热氧稳定性和末端氨基含量的影响。结果表明,UV–944的加入能明显提高聚酰胺6的耐紫外光老化及热氧稳定性,在空气氛围下的起始分解温度提高28℃左右;在185℃老化0.5 h后,改性聚酰胺6的相对黏度下降极低(UV–944质量分数为0.05%时,相对黏度仅下降了3.1%),热氧稳定性明显得到改善。同时,聚酰胺6的末端氨基含量增加,加入UV–944质量分数分别为0.05%,0.2%时,聚酰胺6的末端氨基含量比纯聚酰胺6提高5.1,18.7 mmol/kg,对染色性能明显有所改善。而UV–944对聚酰胺6的热稳定性、熔融温度与结晶温度影响不大。     

Synthesis and characterization of silicon‐containing poly(amide‐amide)s

A modified new aromatic diacid, bis[(4‐carboxyphenyl) 4‐benzamide] dimethylsilane (IV) with preformed amide linkages and a silicon moiety was synthesized and characterized by IR, NMR, mass spectroscopy, and a physical constant. Novel poly(amide‐amide)s were synthesized from IV and aromatic diamines by Yamazaki's direct polyamidation method in N‐methyl pyrrolidinone. The polymers were obtained in excellent yields and showed reduced viscosities in the range of 0.42–6.15 dL/g. They were readily soluble in aprotic polar solvents. These poly(amide‐amide)s showed glass‐transition temperatures of 303–378°C as measured by DSC and showed no weight loss below 377°C in a nitrogen atmosphere. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1610–1617, 2001     

一步法合成对-(四氢-2H-吡喃-2-氧基)苯酚

以对苯二酚为原料,在吡啶对甲苯磺酸盐催化下,与3,4-二氢-2H-吡喃一步反应生成对-(四氢-2H-吡喃-2-氧基)苯酚。通过单因素实验确定了反应的适宜条件:以二氯甲烷为溶剂,原料配比n(対苯二酚)∶n(3,4-二氢-2H-吡喃)=2.5∶1,反应温度16±1℃,反应时间3 h。反应的总收率约为19.2%,目标化合物的纯度为99.8%。目标产物的结构通过LC-MS和1H NMR确证。     

Nd(III)-PVC Membrane Sensor Based on 2-{[(6-aminopyridin-2-yl)imino]methyl}-phenol

We report the development of a novel Nd(III) ion-selective PVC-based membrane sensor, based on 2-{[(6-aminopyridin-2-yl)imino]methyl}phenol (APIMP) as the membrane carrier. The sensor has a Nernstian slope of 19.6±0.3 mV per decade over the concentration range of 1.0× 10⁻⁵−1.0×10⁻² M, and a detection limit of 2.0× 10⁻⁶ M of Nd(III) ions. The potentiometric response of the sensor is independent pH solution in the pH range 3.5–8.5. It has advantages of low resistance, very fast response time (<10 s) and, most importantly, good selectivity with respect to a number of lanthanide ions. Using the proposed membrane sensor in a 6 weeks period caused no significant divergences in its potential response. To assess its analytical applicability the sensor was successfully applied as an indicator electrode in the titration of Nd(III) ion solution with EDTA.     

N(2)-乙酰基-7-[(2-乙酰氧乙氧基)甲基]鸟嘌呤的转糖基作用

研究了N(2 ) 乙酰基 7 [(2 乙酰氧乙氧基 )甲基 ]鸟嘌呤通过转糖基作用生成其9位异构体N(2 ) 乙酰基 9 [(2 乙酰氧乙氧基 )甲基 ]鸟嘌呤的条件 ,转化率为 5 5 %。     

Relation between microstructure and glass transition temperature of poly[(methyl methacrylate)‐co‐(ethyl acrylate)]

The glass transition temperature of a series of samples of the poly[(methyl methacrylate)‐co‐(ethyl acrylate)] copolymer, synthesized at low conversion, were calculated theoretically using the equations of Barton and Johnston. The values obtained are more precise when the probabilities of the compositional diads are derived from the ¹³C NMR data instead of the classical method utilizing reactivity ratios. This can be observed more clearly when the copolymer samples are synthesized at high conversion. Introduction of configuration (tacticity) at the diad level confirms the above observations and slightly improves the calculated values of T_g compared to the initial formulae which were only taking into account the compositional sequences of the copolymer. © 2001 Society of Chemical Industry     

The oxidative polycondensation of 2-[(4-pyridilmethylene)-imino]phenol by molecular O2 in alkaline medium: Synthesis and characterization

Summary The polymer of 2-[(4-pyridilmethylene)-imino] phenol (2-PIP) has been formed from the oxidative polycondensation (OP) reaction by using molecular O₂ as the oxidant in an aqueous alkaline medium between 60–90 °C. The optimum reaction conditions and the main parameters of the process were determined. The yield of polymer was found as 50.1%. The structures of synthesized monomer and polymer were confirmed by FT-IR, UV-vis, ¹H-¹³C-NMR and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC) and solubility tests. The ¹H-¹³C-NMR data shows that the polymerization proceeded with C-C and C-O-C coupling system of ortho and para positions and oxyphenylene according to –OH group of 2-PIP. The molecular weight distribution values of the product were determined from SEC measurement. The number-average molecular weight (M_n), weight-average molecular weight (M_w) and polydispersity index (PDI) values of poly-2-[(4-pyridilmethylene)-imino]phenol (poly-2-PIP) were found to be 11350, 12600 g.mol^-1 and 1.110, respectively. According to thermo gravimetric analysis (TGA), the carbon residues of 2-PIP and poly-2-PIP were found to be 18.17% and 45.10%, respectively, at 1000 °C.     

Synthesis and hydrolysis of chemodegradable cationic surfactants containing the 1,3-dioxolane moiety

In acid-catalyzed reactions of long-chain aliphatic aldehydes (Ia-d wherea=n-C₇H₁₅;b=n-C₉H₁₉;c=n-C₁₁H₂₃; d=n-C₁₃H₂₇), and tridecan-7-on (Ie) with 3-chloro-1,2-propane-diol, 2-alkyl- and 2,2-dihexyl-4-chloromethyl-1,3-dioxolanes (IIa-e) were obtained. They were reacted with anhydrous dimethylamine to obtain, respectively, 2-alkyl-and [(2,2-dihexyl-1,3-dioxolan-4-yl)methyl] dimethylamines (IIIa-e), which were quaternized with methyl bromide to obtain the desired ammonium bromides (IVa-e). The structure and purity of the compounds was proved by mass spectrometry and proton nuclear magnetic resonance spectroscopy. Additionally, [(2-methyl-1,3-dioxolan-4-yl)methyl] trimethylammonium bromide and [(2,2-dimethyl-1,3-dioxolan-4-yl)-methyl] trimethylammonium bromide were synthesized as nonaggregating standards. Hydrolysis reactions of the synthesized ammonium bromides were performed by 0.1 M hydrochloric acid in 1∶1 (vol/vol) 1,4-dioxane-water mixtures at 50, 60 and 70°C. Rate constants of hydrolysis reactions were determined by observing carbonyl group formation at 280 nm. The hydrolytic reactivity of the studied surfactants (IVa-c,e) was determined under unaggregated conditions. Compound IVd showed decreased reactivity. The length of the 2-alkyl group has a minor effect on rate constant values. The influence of various substituents at the C-4 atom of the 2-nonyl-1,3-dioxolan-4-yl derivatives on rate constants was also investigated.     

支链12-冠-4衍生物的合成及对Li离子配合的研究

以羟甲基-12-冠-4和1,6-二溴己烷、1,10-二溴癸烷为原料,在KH催化下,分别合成一溴己氧基12-冠-4和一溴癸氧基12-冠-4;将一溴癸氧基12-冠-4与硫脲加到无水乙醇中,反应过夜合成至今还未见报道的巯基癸氧基12-冠-4,并对其进行表征确认。在不同的pH条件下,分别比较了3种化合物对Li+和Na+的选择配合情况。结果表明,一溴己氧基12-冠-4和一溴癸氧基12-冠-4对Li的配合比都是1∶1,在氯仿中的萃取率不随冠醚环上支链的长短变化而变化,但随pH的增大而增大,达峰值97.69%后趋于稳定;巯基癸氧基12-冠-4由于巯基水解的效应对Li配合物的萃取能力稍差,且随pH的增大而减小,在75.76%后趋于稳定。同时它们对钠的萃取能力则较差。由此可见,12-冠-4对Li具有很好的选择配合能力,该研究为冠醚更广应用提供了一定的基础。     

药物中间体2-[(2′-氰基联苯-4-基)甲基氨基]-3-硝苯甲酸乙酯的制备

本文介绍了以3-硝基-2-叔丁氧甲酰氨基苯甲酸乙酯为原料，在碱性条件下与4-(2-氰基苯基)-1-溴甲苯发生亲核取代反应制备2-[(2′-氰基联苯-4-基)甲基氨基]-3-硝苯甲酸乙酯的方法，产品经核磁共振验证其结构，产品收率达83％。本合成工艺条件温和，适合工业化生产。     

Identification of Cyclopropaneoctanoic Acid 2-Hexyl in Human Adipose Tissue and Serum

Fatty acids containing a cyclopropane ring in their structure (cyclopropane FA) have been found in a wide variety of bacteria, a number of protozoa, and Myriapoda. Little is known about cyclopropane FA in mammal, especially in human tissues. The present study deals with the identification of cyclopropane FA in adipose tissue and serum of humans and rats. Fatty acids extracted from the adipose tissue and serum obtained from obese women during bariatric surgery were methylated and analyzed on GC–MS. We have identified: cyclopropaneoctanoic acid 2-hexyl, cyclopropaneoctanoic acid 2-octyl, cyclopropanenonanoic acid, and 2-[[2-[(2-ethylcyclopropyl)methyl]cyclopropyl]methyl] acid in human adipose tissue. We confirmed the presence of cyclopropaneoctanoic acid 2-hexyl by derivatization of FA extracted from human adipose tissue to picolinyl esters. Cyclopropaneoctanoic acid 2-hexyl was the main cyclopropane FA (approximately 0.4 % of total fatty acids in human adipose tissue, and about 0.2 % of total fatty acids in the serum). In adipose tissue cyclopropaneoctanoic acid 2-hexyl was found mainly in triacylglycerols, whereas in serum in phospholipids and triacylglycerols. The cyclopropaneoctanoic acid 2-hexyl has also been found in serum, and adipose tissue of rats in amounts comparable to humans. The content of cyclopropaneoctanoic acid 2-hexyl decreased in adipose tissue of rats maintained on a restricted diet for 1 month. In conclusion, we demonstrated that cyclopropaneoctanoic acid 2-hexyl is present in human adipose tissue and serum. Adipose tissue cyclopropaneoctanoic acid 2-hexyl is stored mainly in triacylglycerols and the storage of this cyclopropane FA is affected by food restriction.     

Water‐soluble copolymers. I. Biodegradability and functionality of poly[(sodium acrylate)‐co‐(4‐vinylpyridine)]

As a biodegradable functional polymer, poly[(sodium acrylate)‐co‐(4‐vinylpyridine)] [P(SA‐co‐4VP)] containing a small amounts of 4‐vinylpyridine groups were prepared and their biodegradability, dispersity, and complex performance were analyzed. The polymers can be useful as detergent builders and dispersants. It was found that the biodegradation of P(SA‐co‐4VP) was more conspicuous when content of the 4‐vinylpyridine in the copolymer was larger. This indicates that the 4‐vinylpyridine, which acts as biodegradable segments, should be incorporated into the polymer main chain in such a manner that they are digested by activated sludge. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1953–1957, 1999     

Poly[(2-Hydroxy-4-Methoxy Benzophenone) Butylene] Resin and its Polychelates with Lanthanides(III): Synthesis and Characterization

ABSTRACT

The resin (polymeric ligand) was prepared from 2-hydroxy-4-methoxy benzophenone with 1,4-butane diol in the presence of polyphosphoric acid as a catalyst at 160°C for 9 h. The poly[(2-hydroxy-4-methoxy benzophenone) butylene] L = H(HMBP-BD) form 1:2, ML₂, complexes with M = La(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), and Dy(III). The polymeric ligand and its polychelates were characterized by elemental analyses, electronic spectra, and magnetic susceptibilities, IR-spectroscopy, NMR, and thermogravimetric analyses. The number average molecular weight (M¯n) of the resin was determined by Vapour Pressure Osmometry (VPO). All the polychelates are paramagnetic in nature. The resins and their polychelates were screened for their antimicrobial activity against E. coli, B. substilis, S. aureus (bacteria), and S. cerevisiae (yeast). It was found that the polychelates show good antimicrobial activity compared to the free polymeric ligand.     

5-(4-羟基苄叉)-噻唑烷-2,4-二酮的合成

5-(4-羟基苄叉)—噻唑烷-2,4-二酮是抗糖尿病药的关键中间体,本文以硫脲为原料,经闭环、中和、水解、缩合4步反应合成得到目标物,总收率40%。