N─甲基哌嗪-哌嗪及水-N─甲基哌嗪二元体系汽液平衡的研究

引言N──甲基哌嗪是重要的医药中间体,也是合成染料的原料,在制药与高分子化学工业中具有广泛的应用．N──甲基哌嗪合成产物的分离精制中迫切需要相关体系即N──甲基哌嗪──哌嗪以及水──N──甲基哌嗪两个体系的汽液平衡数据,而这方面的数据国内外未见文献报道．为了满足过程开发与工程设计的需要,本工作测定了N──甲基哌嗪──哌嗪、水──N──甲基哌嗪的恒压（0.1013MPa）汽液平衡数据．实验中采取有效的措施克服哌嗪熔点高、吸湿性等特性带来的难度．实测结果采用Wilson方程、NRTL方程进行关联,以及UNIFAC功能团法…     

Bifunctional Inhibitors of Influenza Virus Neuraminidase: Molecular Design of a Sulfonamide Linker

The growing resistance of the influenza virus to widely used competitive neuraminidase inhibitors occupying the active site of the enzyme requires the development of bifunctional compounds that can simultaneously interact with other regulatory sites on the protein surface. When developing such an inhibitor and combining structural fragments that could be located in the sialic acid cavity of the active site and the adjacent 430-cavity, it is necessary to select a suitable linker not only for connecting the fragments, but also to ensure effective interactions with the unique arginine triad Arg118-Arg292-Arg371 of neuraminidase. Using molecular modeling, we have demonstrated the usefulness of the sulfonamide group in the linker design and the potential advantage of this functional group over other isosteric analogues.     

Curing of epoxy resins with citric acid–piperazine salt

Citric acid–piperazine salt was prepared with a molar ratio of acid–piperazine of 2.9. The salt was characterized by thermal calorimetry, ¹³C NMR and IR spectroscopy. The piperazine content in the salt was 52%. A typical formulation was achieved by mixing the salt with the diglycidyl ether of bisphenol A (DGEBA). The heat of reaction was measured by a calorimeter and the evaluated peak resulted from the simultaneous endothermic salt decomposition and exothermic network formation. The heat of reaction value was −ΔH = 18kJ/eq. for the stoichiometric ratio, and the glass transition temperature, T_g, was 95°C. The heat of reaction evolved and the T_g value of piperazine–epoxy were determined for comparison with the salt–epoxy system.     

Solubility advantage of sulfanilamide and sulfacetamide in natural deep eutectic systems: experimental and theoretical investigations

Objective: The aim of this study was to explore the possibility of using natural deep eutectic solvents (NADES) as solvation media for enhancement of solubility of sulfonamides, as well as gaining some thermodynamic characteristics of the analyzed systems.

Significance: Low solubility of many active pharmaceutical ingredients is a well-recognized difficulty in pharmaceutical industry, hence the need for different strategies addressing this problem. Among such strategies, those that are environmentally and economically beneficial are of particular interest.

Methods: The solubility of sulfanilamide and sulfacetamide in 21 different NADES compositions comprising choline chloride with sugars or sugar alcohols was measured spectrophotometrically. Thermodynamic parameters describing the studied systems were determined using the COSMO-RS computational protocol.

Results: All of the considered NADES compositions gave an increase in solubility of the studied sulfonamides, with the highest solubilities obtained for the system comprising choline chloride and glycerol in unimolar proportions, which gave a solubility advantage of 83.7 and 73.8 for sulfanilamide and sulfacetamide, respectively. Theoretical studies indicated that the dissolution of both considered sulfonamides has a low endothermic character, with the lowest enthalpy values obtained for the most optimal, i.e. unimolar, proportions. The non-monotonous trend of enthalpy of dissolution was also discussed in terms of intermolecular interactions.

Conclusions: The obtained results show the feasibility of using NADES as solubility enhancers for sulfonamides and encourage for further exploration in this field.     

分子印迹固相萃取高效液相色谱联用检测猪肉中的磺胺类兽药残留

采用本体聚合法,以磺胺二甲基嘧啶作为模板分子,甲基丙烯酸作为功能单体,甲基丙烯酸羟乙酯作为亲水性功能单体,乙二醇二甲基丙烯酸酯和3-（三甲氧基甲硅烷基）丙基丙烯酸酯同时作为交联剂,偶氮二异丁腈作为引发剂,合成磺胺二甲基嘧啶分子印迹聚合物,印迹聚合物对模板分子的饱和吸附量可以达到11.37 mg/g,选择性实验中印迹聚合物对磺胺类的吸附量明显大于竞争物,对7种磺胺类药物（磺胺二甲基嘧啶、磺胺嘧啶、磺胺甲氧嗪、磺胺异噁唑、磺胺噻唑、磺胺对甲氧嘧啶、磺胺甲基嘧啶）均具有特异性吸附效果。同时建立了固相萃取与高效液相色谱联用的方法检测猪肉中痕量磺胺类药物含量,结果表明该方法对加标的7种磺胺类药物检测限为1.7⁴.5μg/L,回收率可达73.9%⁸5.4%,且该检测方法简单、便捷、灵敏度高。      

哌嗪合成催化剂研究进展

综述了单一金属催化剂、复合型金属催化剂、分子筛催化剂以及固体酸催化剂在哌嗪合成中的应用,提出开发反应条件温和、可直接得到无水哌嗪的催化剂是哌嗪合成催化剂的研究开发重点.     

1,4-二(5,5-二甲基-1,3-二氧-2-磷环己基膦酰基)哌嗪的合成研究

以新戊二醇、三氯氧磷、哌嗪为原料,用酐法合成了无卤膨胀型阻燃剂1,4-二(5,5-二甲基-1,3-二氧-2-磷环己基膦酰基)哌嗪,得出其最佳工艺条件为新戊二醇磷酸酐和哌嗪的摩尔比为1∶1,以二甲苯做溶剂,在140℃下回流分水反应8h,产率达91.6%。并用红外、核磁对结构进行了表征。     

1-(4-羟基苯基)-4-(4-硝基苯基)哌嗪的合成概述

三唑类药物是目前抗真菌药的主流,特别是用于治疗深部真菌感染。1-（4-羟基苯基）-4-（4-硝基苯基）哌嗪是其重要的药物中间体,作为新-代抗真菌药关键中间体其的合成已成为研究热点。较全面地介绍了1-（4-羟基苯基）-4-（4-硝基苯基）哌嗪的各种合成路线。其合成途径基本上是先制备单N-芳基取代哌嗪,产物继续和适当的芳基卤化物进行N’-芳基化反应,得到1-（4-羟基苯基）-4-（4-硝基苯基）哌嗪。     

胶体金免疫层析法检测食品中的磺胺类药物残留

建立了一种用于快速检测动物源性食品中五种磺胺类药物,磺胺异噁唑(SIZ)、磺胺噻唑(STZ)、磺胺对甲氧嘧啶(SME),磺胺甲二唑(SMT)、磺胺氯哒嗪(SCPA)残留的胶体金免疫层析方法.采用柠檬酸三钠还原法制备粒径为20nm的胶体金,将对磺胺类药物具有广谱特异性的多克隆抗体-肢体金复合物喷涂在玻璃纤维上,并将人工合...     

Palladium‐Catalyzed Mono‐Selective ortho C?H Arylation of Aryl Sulfonamides in Water: A Concise Access to Biaryl Sulfoamide Derivatives

A green atom‐economical method for the synthesis of biaryl sulfonamide derivatives via palladium(II)‐catalyzed C H bond activation by employing an amino acid moiety as the bidentate directing group has been developed. The protocol proceeded efficiently in water; high yields and broad substrate scope were achieved. The reaction shows good functional group compatibility and proceeds in a highly selective manner at the ortho position of arenes connected to sulfonamide sulfur atoms. This auxiliary can be easily removed either by acidic hydrolysis, or converted into primary biaryl sulfomamides with a 30 mol % amount of CuO as catalyst. Mechanistic studies show that the present bidentate directing group is essential for promoting ortho C H bond activation of arenes connected to sulfonamide sulfur atoms.