盐酸奈法唑酮的合成

盐酸奈法唑酮是一类新型抗抑郁药.先用间氯苯胺与二乙醇胺环化合成1-(3-氯苯基)哌嗪,再与1-溴-3-氯丙烷反应制得1-(3-氯丙基)-4-(3-氯苯基)哌嗪盐酸盐,最后与5-乙基-4-(2-苯氧乙基)-1,2,4-三唑-3-酮反应得到盐酸奈法唑酮.产物结构经IR,MS,1H NMR及13C NMR确证.     

氧氟沙星的核磁共振波谱性质研究

结合1H, 13C NMR, DEPT, COSY, HSQC, HMBC谱和碳氟偶合裂分行为, 对酸性及碱性溶液中氧氟沙星(Ofloxacin, OFL)的1H和13C谱分别进行归属, 研究了哌嗪环亚甲基构成的AA'BB'复杂自旋体系中各H的化学位移. 发现噁嗪环上的甲基处于直立键; 5H在酸性溶液中化学位移移向低场, 这可能与形成C—H…O弱氢键有关; 在碱性溶液中, OFL的羧基变为羧酸根, 造成羧基和羰基周围碳原子上π电子重新分布, 导致相应C的化学位移和碳氟偶合常数发生明显变化.     

Genistein complexes with amines. Part II: ab initio study of the complexes with piperazine and triethylamine

The piperazine and triethylamine complexes of genistein, exhibiting high immunosuppressant activity, were ab initio modeled at RHF/6-31G^** level and results were compared with those obtained for genistein–morpholine complexes by X-ray, NMR, and theoretical methods. The most stable genistein–piperazine complex is formed due to hydrogen bonding of genistein's OH group at position C7 to piperazine's nitrogen atom. In the most stable genistein–triethylamine complex genistein's OH group at position C4′ (position para to phenyl substituent) and trimethylamine nitrogen atom are engaged in hydrogen bond formation. The calculations confirmed our previous NMR conclusion that piperazine is more strongly complexed by genistein than is morpholine or triethylamine. The theoretical ¹³C NMR spectra correlate fairly well with the experimental spectra.     

Novel 2-Hydroxypropyltrimethyl Ammonium Chitosan Derivatives: Synthesis,Characterization, Moisture Absorption and Retention Properties

Recent years have seen a steady increase in interest and demand for the use of humectants based on biodegradable natural polymers in many fields. The aim of this paper is to investigate the moisture absorption and retention properties of 2-hydroxypropyltrimethyl ammonium chitosan derivatives which were modified by anionic compounds via ion exchange. FTIR, ¹H NMR, and ¹³C NMR spectroscopy were used to demonstrate the specific structures of chitosan derivatives. The degrees of substitution for objective products were calculated by the integral ratio of hydrogen atoms according to ¹H NMR spectroscopy. Meanwhile, moisture absorption of specimens was assayed in a desiccator at different relative humidity (RH: 43% and 81%), and all target products exhibited enhanced moisture absorption. Furthermore, moisture retention measurement at different relative humidity (RH: 43%, 81%, and drier silica gel) was estimated, and all target products possessed obviously improved moisture retention property. Specifically, after 48 h later, the moisture retention property of HACBA at 81% RH was 372.34%, which was much higher than HA (180.04%). The present study provided a novel method to synthesize chitosan derivatives with significantly improved moisture absorption and retention properties that would serve as potential humectants in biomedical, food, medicine, and cosmetics fields.     

Solution and solid state 13C NMR and X-ray studies of genistein complexes with amines. Potential biological function of the C-7, C-5, and C4'-OH groups

Parent genistein and its new amine complexes with morpholine and piperazine were studied comparatively in the solid and liquid states by X-ray crystallography and 13C and 15N NMR spectroscopy. Biochanine A and its complexes were used as reference. Secondary deuterium isotope effects on 13C chemical shifts in solution were studied in parent isoflavones and their morpholine and piperazine complexes to aid in evaluation of the electronic distribution in both systems. In addition, to quantify the extent of proton transfer as well as to establish strong hydrogen bonding of the 7-OH group in a morpholine complex, proton transfer from the 7-OH group to the piperazine nitrogen atom was also confirmed by 13C NMR in the solid state and by X-ray studies. The effect of 7-OH deprotonation yields a high frequency shift of 7-8 ppm on the C-7 carbon atom of the piperazine complex whereas it is as large as 12 ppm in the morpholine complex in the solid. The former trend is confirmed from solution state concentration studies which also show that the isoflavones have a strong tendency to form complexes with bases. Depending on the pKa difference between the isoflavones and the base this leads either to proton transfer and ion-pair formation or, in the case of a larger pKa difference, to a hydrogen bonded ion pair. The concentration studies show formation of a 1:1 genistein-piperazine complex in DMSO. Addition of water leads to formation of solvent separated ions. The C-5 OH group is involved in strong intramolecular hydrogen bonding leading to a pseudo aromatic ring extending the aromatic part of the drug pharmacophore. The analysis also suggests the way that both the C-7 and C-4' hydroxyl group of genistein may participate in stabilising the ternary inhibitor complexes of tyrosine-specific kinases or DNA topoisomerase II.     

新型N-芳基哌嗪取代苯并呋喃衍生物的合成

以5-二甲氨基水杨醛和2-溴-4'-氟苯乙酮为原料,经缩合和取代反应制得中间体6-二乙氨基-2-[4'-(N-哌嗪基)苯甲酰基]苯并呋喃(2);2与卤代烃反应合成了6个新型的N-芳基哌嗪取代苯并呋喃衍生物(4a~4f),收率76%~93%,其结构经1H NMR,13C NMR和HR-MS(ESI-TOF)表征。     

两种基于哌嗪阳离子的磺酸功能化离子液体的合成及其结构表征和物理性质测定

以哌嗪、1,4-丁磺酸内酯及硫酸或磷酸为原料,合成了两种基于哌嗪阳离子的磺酸功能化酸性离子液体硫酸氢盐([(HSO3-b)2pi]2+.2[HSO4]-)和1,4-二(4-磺酸基丁基)哌嗪磷酸二氢盐([(HSO3-b)2pi]2+.2[H2PO4]-);利用傅立叶变换红外光谱、核磁共振氢谱和碳谱表征了两种产物的结构,并测定了其熔点、黏度、电导率、热稳定性等物理性质.     

Conjugated vinyl derivatives of chitooligosaccharide: Synthesis and characterization

The introduction of a conjugated vinyl group to chitooligosaccharide (COS) has been easily accomplished by the coupling of glycidyl methacrylate (GMA) to COS in aqueous solution without an additional catalyst. Depolymerization of chitosan was carried out by deaminative cleavage using sodium nitrite. The average degree of polymerization of COS could be controlled by varying the molar ratio of sodium nitrite and the amino group of chitosan. The degree of substitution (percentage), as determined by ¹H NMR, of GMA to COS increased up to 60% at a reaction time of 48 h. The structure of products (COS‐GMAs) were identified by Fourier transform infrared spectroscopy, ¹H NMR, and ¹³C NMR. The resulting COS‐GMAs were readily soluble in neutral water, like the original COS, and exhibited an excellent antimicrobial activity. The reactivity of COS‐GMA was investigated by the reaction with poly(vinyl alcohol) (PVA). The reaction products were found to have a lower crystallinity than PVA because of the introduction of the COS‐GMA units. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 880–887, 2001     

2-氰基-2,3-二甲基-3-甲基羰甲基-5-硫酮-吡咯烷的合成

2-氰基-2;3-二甲基-3-甲基羰甲基-5-硫酮-吡咯烷的合成;双甲基环并内酯;双甲基环并内酰胺-内酯;氰基吡咯烷酮;氰基吡咯烷硫酮     

Inorganic–organic hybrid chitosan‐based Schiff base–Ni complex as a novel,highly efficient and recyclable heterogeneous catalyst for synthesis of pyrazolophthalazinediones

A Schiff base based on chitosan was synthesized through treatment of chitosan and p ‐dimethylaminobenzaldehyde in methanol solution. This biopolymeric Schiff base was used to prepare a new first row transition metal complex of Ni(II). The biopolymeric Schiff base and the synthesized tetra‐coordinated complex were characterized using Fourier transform infrared, ¹H NMR and ¹³C NMR techniques. Then, an efficient synthetic method for functionalized 1H –pyrazolo[1,2‐b ]phthalazine‐5,10‐diones was successfully developed using one‐pot domino reaction of ninhydrin and malononitrile with 3‐arylamino‐5,5‐dimethyl‐2‐cyclohexenones catalysed by the chitosan‐based Schiff base complex of Ni(II) at room temperature. The advantages of this protocol are easy work‐up, short reaction times and high yield of products and also the catalyst can be readily isolated from the reaction mixture and recycled without loss of catalytic activity.     

The interaction of 3-methyl-4-nitro-3-thiolene-1,1-dioxide with aliphatic amines

The reactions of 3-methyl-4-nitro-3-thiolene-1,1-dioxide with highly basic amines (pK _a of HB⁺ = 8.97–13.27), morpholine, piperazine, piperidine, cyclohexylamine, diphenylguanidine, and guanidine, proceed via deprotonation of methylene group at the C² atom of sulfolene ring with formation of ammonium thiolene nitronates. The products were characterized by IR, UV, and NMR (¹H, ¹³C, ²D) spectroscopy methods.     

A large sample volume magic angle spinning nuclear magnetic resonance probe for in situ investigations with constant flow of reactants

A large-sample-volume constant-flow magic angle sample spinning (CF-MAS) NMR probe is reported for in situ studies of the reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions. In our approach, the reactants are introduced into the catalyst bed using a fixed tube at one end of the MAS rotor while a second fixed tube, linked to a vacuum pump, is attached at the other end of the rotor. The pressure difference between both ends of the catalyst bed inside the sample cell space forces the reactants flowing through the catalyst bed, which improves the diffusion of the reactants and products. This design allows the use of a large sample volume for enhanced sensitivity and thus permitting in situ(13)C CF-MAS studies at natural abundance. As an example of application, we show that reactants, products and reaction transition states associated with the 2-butanol dehydration reaction over a mesoporous silicalite supported heteropoly acid catalyst (HPA/meso-silicalite-1) can all be detected in a single (13)C CF-MAS NMR spectrum at natural abundance. Coke products can also be detected at natural (13)C abundance and under the stopped flow condition. Furthermore, (1)H CF-MAS NMR is used to identify the surface functional groups of HPA/meso-silicalite-1 under the condition of in situ drying. We also show that the reaction dynamics of 2-butanol dehydration using HPA/meso-silicalite-1 as a catalyst can be explored using (1)H CF-MAS NMR.     

哌嗪取代查尔酮衍生物的合成及其细胞毒活性

以4-甲氧基苯甲醛与2-溴-4’-氟苯乙酮为原料,经羟醛缩合脱水、取代反应生成4-甲氧基-4’-(1-哌嗪基)查尔酮(2),再通过酰化反应合成了10个新型含哌嗪的查尔酮衍生物,其结构经~1H NMR、~(13)C NMR及HRMS确证。采用MTT法初步测试了目标化合物的体外细胞毒活性,结果表明,化合物3e和4d对肿瘤细胞株Hela和A549均表现出较好的细胞毒活性,可做进一步研究。     

Influence of ultraviolet-irradiated oxygen on depolymerization of chitosan

In the present paper, the depolymerization of chitosan was carried out by the ultraviolet-irradiated oxygen treatment. Influence of reaction conditions on depolymerization of chitosan was investigated. The chemical structure of the depolymerized chitosan was characterized by FT-IR and ¹³C NMR spectra. The FT-IR and ¹³C NMR spectra suggested that there was no obvious modification of chemical structure of the depolymerized chitosan. The X-ray diffraction analysis showed that crystalline structure of chitosan can be destroyed by ultraviolet-irradiated oxygen. The use of depolymerization of chitosan by ultraviolet-irradiated oxygen treatment can be a convenient, timesaving, and cost-efficient method for replacing the expensive and time-consuming enzymatic or chemical methods that are currently used to depolymerize chitosan.     

Synthesis of Hydroxypropyltrimethyl Ammonium Chitosan Derivatives Bearing Thioctate and the Potential for Antioxidant Application

Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) is one of the most important water-soluble chitosan derivatives; its derivatives have gained growing attention due to their potential biomedical applications. Here, hydroxypropyltrimethyl ammonium chitosan derivatives bearing thioctate (HACTs), with different degrees of substitution of thioctate, were prepared using HACC and α-lipoic acid as the reaction precursors, using an ion exchange method. The structural characteristics of the synthesized derivatives were confirmed by FTIR, ¹H NMR, and ¹³C NMR spectroscopy. In addition, their antioxidant behaviors were also investigated in vitro by the assays of reducing power, and scavenging activities against hydroxyl radicals and DPPH radicals. The antioxidant assay indicated that HACTs displayed strong antioxidant activity compared with HACC, especially in terms of reducing power. Besides, the antioxidant activities of the prepared products were further enhanced with the increase in the test concentration and the degrees of substitution of thioctate. At the maximum test concentration of 1.60 mg/mL, the absorbance value at 700 nm of HACTs, under the test conditions, was 4.346 ± 0.296, while the absorbance value of HACC was 0.041 ± 0.007. The aforementioned results support the use of HACTs as antioxidant biomaterials in food and the biomedical field.     

Ionic conductivity and tensile properties of hydroxyethyl and hydroxypropyl chitosan membranes

Hydroxyethyl chitosan and hydroxypropyl chitosan were prepared through the reaction of alkali‐chitosan with 2‐chloroethanol and propylene epoxide, respectively. Fourier transform infrared and ¹³C NMR measurements were made to examine the substitution on the chitosan unit. According to a comparison of the peak areas between the modified chitosan and unmodified chitosan and the integration of peak areas of ¹H NMR spectra, for both modified chitosans, the maximum degree of substitution was less than 25%. The ionic conductivity and mechanical properties of modified chitosan membranes were investigated. In comparison with the unmodified chitosan membrane, hydrated hydroxyethyl and hydroxypropyl chitosan membranes with a higher degree of substitution showed an increase in ionic conductivity of about one order of magnitude; moreover, the crystallinity of hydroxyethyl and hydroxypropyl chitosan membranes was remarkably reduced, and their swelling indices increased significantly. However, these modified membranes did not exhibit significant changes in their tensile strength and breaking elongation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1379–1397, 2004     

羟基中环二胺接枝壳聚糖的合成与表征

以具有环氧活性基的壳聚糖与3-羟基-1，5-二氮杂环庚烷或3-羟基1，5-二氮杂环辛烷反应，合成了两种含羟基的氮杂冠醚壳聚糖衍生物，其组成及结构经元素分析，IR，X-射线粉末衍射及^13C NMR等方法确证。     

Dithiocarbamated chitosan as a potent biopolymer for toxic cation remediation

The biopolymer chitosan was chemically modified with dithiocarbamate, characterized by elemental analysis, IR, (13)C NMR and TG, and applied for lead, copper and cadmium removal. Based on sulfur elemental analysis an amount of 2.66 mmol g(-1) of pendant chain was incorporated in the original biopolymer, as also demonstrated through the appearance of a signal at 201 ppm in the (13)C NMR in the solid state. The TG curve demonstrated that the final product is more stable than the precursor chitosan. The sorption capacity of modified biopolymer was determined through a batchwise methodology, with maximum capacities of 2.24; 1.14 and 0.84 mmol g(-1) for divalent lead, copper and cadmium from aqueous solution, respectively. The highest sorption capacity for lead reflects the soft cation/sulfur interaction. The experimental data were adjusted to the Langmuir, the Freundlich and the Temkin sorption isotherm models using both linear and nonlinear regression analysis.     

Spectroscopic characterization and preparation of low molecular,water‐soluble chitosan with free‐amine group by novel method

Low molecular, water‐soluble chitosan (LMWSC) with a free amine group was prepared by the novel salts‐removal method described in this study. A weight‐average molecular weight and degree of deacetylation (DDA) of LMWSC were determined by viscometry and Kina titration, resulting in 18,579 Da and 93% DDA, respectively. In the Fourier transform infrared spectroscopic, ¹H NMR, and ¹³C NMR spectra the absorption band by the carboxyl group derived from lactic acid and the impurities formed in the enzymatic process disappeared or were significantly lower than that of the control chitosan. Also, from the ¹H NMR and ¹³C NMR spectra the empirical value for the area ratio of the proton and carbon corresponds nearly to its theoretical values. The matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum identified the difference in the two adjacent peaks as 161. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3796–3803, 2002     

Co(II) anchored glutaraldehyde crosslinked magnetic chitosan nanoparticles (MCS) for synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetrasubstituted imidazoles

A simple, highly efficient and green synthesis of 2,4,5‐trisubsituted and 1,2,4,5‐tetrasubstituted imidazoles was developed using a novel MCS‐GT@Co(II) magnetically recoverable and recyclable catalyst under refluxing conditions with ethanol as a solvent. The catalyst was prepared by immobilization of chitosan onto Fe₃O₄ using glutaraldehyde as crosslinker followed by Co(II) ion immobilization via cobalt acetate. The catalyst was characterized using various techniques. For organic products determination, ¹H NMR, ¹³C NMR and Fourier transform infrared spectroscopies were used. The reaction was also tried with individual components of the catalyst, but the synergistic effect of the components in the prepared catalyst showed the highest yield and shortest reaction time.