A facile synthesis of thiosemicarbazides containing the 4-antipyrinyl group under microwave irradiation in solvent-free conditions

A simple, efficient and eco-friendly method for the synthesis of a series of thiosemicarbazides containing 4-antipyrinyl group under microwave irradiation has been reported, no solvent and catalyst was used. Five of them are new compounds.     

硫磺延伸产品的现状及展望

介绍了硫脲、甲硫醇、蛋氨酸、硫肥、含硫建筑材料、不溶性硫磺、Na-S电池等硫磺延伸产品情况.指出硫酸企业要以硫磺、CS2、SO2、SO3和硫酸为原料,构建多层次、多元化的精细硫化工产业链,使硫酸企业走上特色化工和精细化工之路.     

苯薄荷醇衍生物和萘薄荷醇衍生物的合成与表征

主要研究二环[4.2.0]辛酮中间体薄荷醇衍生物的合成工艺.以(-)-1 R,2S,5R-8-苯薄荷醇和(-)-1R,2S,5R -8-萘薄荷醇为原料,通过酯化反应合成目标化合物,产率分别为58.7%、92%.其结构经 1HNMR、13CNMR进行了表征,并对标题化合物的构象稳定性和晶体结构进行了研究.     

New derivatives of indazole as electronically active materials

Synthesis and thermal, optical, electrochemical and photoelectrical properties of new indazole-based electroactive materials are reported. 1-Phenyl-5(6)-[N,N-(bisphenyl)]aminoindazoles and their methoxy-substituted analogues exhibit high thermal stabilities with the onset temperatures of thermal degradation ranging from 352 to 424 °C. The synthesized indazole derivatives form glasses with glass transition temperatures ranging from 35 to 39 °C. The synthesized compounds are electrochemically stable: their cyclic voltammograms show one reversible oxidation couple and no reduction waves. The ionization potentials of the solid samples of the synthesized materials are in the range of 5.3-5.9 eV. Methoxy-substituted derivatives show lower ionization potentials. Time-of-flight hole drift mobilities of 50% solid solution of 1-(4-methoxyphenyl)-5-{N,N-[bis(4-methoxyphenyl)]}aminoindazole in bisphenol Z polycarbonate reach 10⁻⁵ cm²/V s at high electric fields.     

对甲酚衍生物催化氧化合成对羟基苯甲醛衍生物

阐述了对甲酚衍生物催化氧化合成对式苯甲醛衍生物的研究状况及近期研究动态,对Ｃｏ盐催化剂、Ｃｏ／Ｃｕ双金属催化剂以及其他催化剂对对甲酚衍生物选择性催化氧化的性能作一评述。     

Synthesis of novel quaternary ammonium salts from 1, 2-benzothiazine derivatives

A series of novel 1,2-benzothiazine based quaternary ammonium salts were successfully prepared through different organic transformations. Products of all transformations and final salts were separated out and purified. The product yields were good to excellent for all transformations. Resultant 1,2-benzothiazine based cationic amphiphilic systems were stabilized using different counter anions. All final products were confirmed by ¹HNMR and ¹³CNMR analyses. 1,2-benzothiazine based quaternary ammonium salts have a potential to be employed as a phase transfer catalyst for various reactions in future.     

Synthesis and characterization of surface-active compounds derived from cholesterol derivatives and glucose

The synthesis and characterization of surface-active compounds based on various steroid derivatives and glucose are presented. The hydrophobic and hydrophilic parts of the compounds were linked via glucosidic bonds. All compounds were found to have very low water solubility and only limited solubility in various organic solvents. The compounds were investigated according to their ability to interact with an anionic surfactant, sodium dodecylsulfate (SDS), in order to induce a decrease in the critical micelle concentration (CMC) of the surfactants. This synergistic effect was pronounced for cholestanol-6-on-β-D-glucopyranoside and for cholestan-3,6-diol-β-D-glucopyranoside. These two compounds lowered the CMC from 8 to 6 and 0.6 mM, respectively, for water solutions of SDS/glucoside with a molar ratio of 92∶8. Furthermore, the ability of the compounds to stabilize lipid membranes, in liposomes, at varying concentrations of Ca²⁺, was studied. The compounds were, as expected, found to induced stabilization similar to that of cholesterol.     

5-Pyrenylidene-hydantoin, 2-thiohydantoin derivatives: synthesis,S- and N-alkylation

5-Pyrenylidene-2-thiohydantoin derivatives 2a–d were prepared by condensation of pyrene-1-carboxaldehyde with 2-thiohydantoin derivatives. Compounds 2a,b undergo Mannich reaction with formaldehyde and morpholine to give the corresponding Mannich products 3a,b respectively. S- and N-monoalkyl-5-pyrenylidene-hydantoin derivatives 5a,b and 6a,b were prepared by reaction of 5-pyrenylidene-2-thiohydantoin sodium salts with 1,3-dioxolan-methylsulfate derivatives. Deprotection of the products afforded 5-pyrenylidene-hydantoin (7), S- and N-dihydroxy derivatives 8a,b and 9a,b respectively. Reaction of 2a with methyl iodide afforded the corresponding S-methyl derivative 10, which reacted with secondary amines such as morpholine and piperidine afforded the glycocymidine derivatives 11a,b. Reaction of 2a with (2,3,4,6-tetra-O-acetyl-α-? D-glucopyranosyl)bromide afforded a mixture of S- and N-glucoside derivatives 12 and 13 respectively. Deprotection of 12 afforded compound 7, while deprotection of 13 furnished 5-Pyrenylidene-3-? D-glucopyranosyl-2-thiohydantoin (14). Reaction of 7 with propargyl chloride in DMF afforded the monoalkynyl- and bis-alkynyl-hydantoin derivatives 15 and 16, respectively. Reaction of 15 with p-bromophenyl-ether derivative 17 yielded the bis-alkynyl derivative 18.     

杯芳烃及其衍生物的研究进展

杯芳烃是一类“新型”的具有独特空穴结构的大环化合物,本文综述了杯芳烃的合成,以及其衍生物的进展情况。     

咪唑及其衍生物的应用

综述了咪唑及其衍生物在分化试剂,表面活性剂,医药,农药,合成材料,有机合成试剂等领域中的应用。     

异香豆素类衍生物的卤化烷氧基化反应

以N-溴代丁二酰亚胺(NBS)、N-氯代丁二酰亚胺(NCS)分别为溴代、氯代试剂,醇类化合物作为反应原料及溶剂,实现了异香豆素类衍生物3,4-位的卤化烷氧基化反应.室温(25℃)下即可在3,4-位之间发生加成反应,合成具有潜在药理活性的异色满-1-酮类衍生物.对4-溴-3-甲氧基-3-苯基异色满-1-酮(Ⅳa)的合成反...     

木聚糖酯化衍生物的合成、性能及应用研究进展

综述了近年来木聚糖酯化衍生物的合成途径,包括羧酸酯化、硫酸酯化和芳香酯化等。分析了木聚糖酯化衍生物的性能以及应用,同时讨论了木聚糖硫酸酯化衍生物的结构与功能之间的关系,并对木聚糖酯化改性及应用发展趋势进行了简要阐述。     

几种水杨醛衍生物的合成以及Schiff-碱双位配体与其还原产物的制备

报道了5-甲基-3-亚甲基哌啶水杨醛及5-溴-3-亚甲基哌啶水杨醛和5-溴-3-亚甲基吗啡林水杨醛的合成;同时报道了含二级胺桥联的Salen-类Schiff碱及其还原产物的合成。初步研究分析了双位配体Schiff碱的金属盐配合物的稳定性及其水解产物。并通过核磁共振、红外、质谱等手段对相关化合物结构进行了表征。     

双噁唑啉类衍生物的合成及表征

对苯二甲酸二甲酯肼解制得对苯二甲酰肼,后者与不同的芳香醛缩合得到对苯二甲酰腙,然后与乙酸酐环合,合成出9个双唑啉衍生物,其结构通过IR、1HNMR、MS及元素分析确证并对其波谱学特征予以讨论。     

取代异唑衍生物的合成

对文献中有关取代异唑衍生物的合成方法及反应特点进行了归纳和综述     

川芎嗪哌嗪衍生物的合成与表征

以川芎嗪三水合物为原料,经氧化、酰化、水解、卤代和烃化反应合成了4个川芎嗪哌嗪衍生物,通过红外光谱、核磁共振氢谱和质谱对其结构进行了表征。     

Solvent extraction of silver(I) from nitrate media using thiourea derivatives

Liquid–liquid extraction of Ag(I) from nitrate solutions using N‐(N′,N′‐diethyl thiocarbamoyl)‐N″‐phenylbenzamidine (TCBA) and 1‐6,‐diethylcarbamoyl imino‐1,6‐diphenyl‐2,5 dithiahexane (TCTH) dissolved in cumene has been studied. The extraction of Ag(I) from 1 mol dm⁻³ NO₃⁻ solutions by TCTH and TCBA was investigated as a function of several variables: equilibration time, organic phase diluent, pH of aqueous phase, Ag(I) and NO₃⁻ concentration in aqueous phase as well as TCBA and TCTH concentrations. Experimental equilibrium data were analysed numerically using the programs LETAGROP‐DISTR and LETAPL and the results showed that Ag(I) extraction could be explained assuming the formation of AgL and AgNO₃HL with TCBA (HL) and AgNO₃S with TCTH (S). The metal extraction was not influenced significantly by the structures of the thiourea derivatives used as extractants. The back extraction of Ag(I) from loaded organic phase was performed using different strippants and 0.5 mol dm⁻³ NaSCN was found to be efficient for this purpose. © 2000 Society of Chemical Industry     

Rheological properties of guar and its methyl, hydroxypropyl and hydroxypropyl-methyl derivatives in semidilute and concentrated aqueous solutions

We report on a comparative study of the rheological properties of guar [GG], methyl guar [MG], hydroxypropyl guar [HPG] and hydroxypropyl-methyl guar [MHPG] polymers aqueous solutions in semidilute (both unentangled and entangled) and concentrated regimes, using oscillatory and steady-shear techniques. In the dilute regime, molecular weights and radii of gyration have been investigated by means of light scattering measurements.Data obtained from steady-shear rheology were satisfactorily analyzed according to Cross model and the effects of polymer concentration and temperature on the rheological behaviour of guar and guar derivatives have been investigated and discussed in terms of rheological parameters, such as the zero-shear viscosity η₀, the characteristic time τ and critical coil-overlap concentration C^∗.The storage and loss moduli of guar and guar derivatives aqueous solutions have been measured using angular frequencies in the range between 10⁻³ and 10 rad/s. The data have been analyzed using the “blob” model for semidilute solutions and the scaling approach proposed by Rubinstein, Dobrynin and Colby for concentrated solutions. These rheological parameters obey a time-concentration superposition principle, so that master curves can be constructed over a wide frequency range. Moreover, we show that, at lower temperatures, these systems behave as thermo-rheological simple systems, in that the oscillatory shear response at different temperatures can be superimposed according to the empirical time-temperature superposition principle. Although these systems can be conveniently described within a unifying scaling model, the behaviour of guar derivatives are somewhat different. At higher temperatures, relatively small deviations from the scaling behaviour of the storage modulus of MG and MHPG polymers were observed. These findings can be justified by a structural re-organization of the macromolecular network, due to the hydrophobic interactions.     

环烷酸衍生物的合成与应用

简要介绍了环烷酸衍生物的合成工艺及应用，并对开发该类产品的可行性进行了探讨。     

In vitro comparative hemostatic studies of chitin,chitosan, and their derivatives

The effects of chitin, chitosan, and their derivatives on in vitro human blood coagulation and platelet activation were comparatively studied. The coagulation was assessed by the measure of the whole blood clotting time (WHBCT) and plasma recalcification time (PRT). The tested materials were chitin, chitosan, partially N‐acetylated chitosan (PNAC), N,O‐carboxymethylchitosan (NOCC), N‐sulfated chitosan, N‐(2‐hydroxy)propyl‐3‐trimethylammonium chitosan chloride, and SPONGOSTAN® standard (a positive control). The results revealed that the WHBCTs of whole blood mixed with chitin, chitosan, NOCC, or SPONGOSTAN® standard were significantly decreased with respect to that of the pure whole blood (a blank control) (P < 0.05), while the WHBCT value of whole blood mixed with PNAC was not significantly reduced. However, the presence of PNAC significantly lowered the PRT value, similar to the addition of chitin, NOCC, or SPONGOSTAN® standard. Chitosan was found to reduce PRT, but not significantly. In the platelet adhesion and activation studies, the morphology of platelets adherent to the film surfaces of tested materials was examined using a scanning electron microscopic technique. Because of their effective coagulation activites, chitosan, PNAC, and NOCC were further evaluated to determine how platelets behaved when in contact with these film samples for given periods. It was found that NOCC activated platelets most effectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 445–451, 2006