二环吡唑啉衍生物的合成及其抗炎活性

设计合成了１３个二环吡唑啉及其衍生物，其中９个为未见文献报道的新化合物，初步抗炎实验表明，大部分化合物都有程度不同的抗炎活性，部分化合物的抗炎活性与布洛芬相当。     

Synthesis of HC toxin and related cyclopeptides containing the (L-Ala-D-Ala-L-Ada-D-Pro) sequence

In studies leading to HC toxin synthesis, a phytotoxic cyclic tetrapeptide with the sequence cyclo (L-Ala-D-Ala-L-Aoe-D-Pro), we have determined optimal conditions for the cyclization which constitutes one of the most important steps in the synthesis of the toxin. All four possible sequences containing an optically active precursor, i.e. L-Ada = (2 S)-2-amino-9-decenoic acid instead of Aoe, have been prepared and subjected to cyclization. Owing to the differences in racemization risk during activation of the terminal carboxyl aminoacid different cyclization procedures have been applied. Cyclopeptide yields and selectivity between cyclomonomer and dimer both containing the title sequence are mainly controlled by the linear precursor sequence. The cyclic tetrapeptide is only obtained with D-proline in the C-terminal position, the best yield reached by the -ONSu activation method. Starting from the peptide, the (9S, 9R) HC toxin epimer on the epoxidic carbon atom has been further synthesized in two steps.     

Cyclization studies with a model pentapeptide

A pentapeptide with the sequence Gly-Ala-d -Val-Leu-Ile was designed for a study of cyclization. Isoleucine was selected as the C -terminal residue in order to determine, from the amount of alloisoleucine in the cyclic product, the extent of racemization during activation and ring closure. The insolubility of cyclo (glycyl-alanyl-d -valyl-leucyl-isoleucyl) in the commonly used solvents facilitated its isolation and thus the evaluation of comparative experiments. Because of its thermal stability the cyclopentapeptide could be purified by sublimation in vacuo. The results of cyclization experiments carried out with this model suggest that separation of the steps of activation and coupling is preferable to cyclization with the help of coupling reagents, that is to the execution of activation and ring closure in a single operation.     

依替巴肽一级结构的确证

目的:对合成的依替巴肽一级结构进行确证。方法:采用串联质谱序列分析法测定了氨基酸序列,采用 ESI-MS/MS 对依替巴肽的相对分子质量和肽链环化结构进行了确证,采用~1 HNMR 进一步确定了依替巴肽的结构。结果:串联质谱序列分析法,证实合成肽氨基酸序列和非天然氨基酸结构正确;ESI-MS/MS 测得样品准确的相对分子质量为831.48,与依替巴肽的参照品及理论值(831.96)完全一致;质谱分析确证合成依替巴肽分子内形成了一个正确的二硫键;~1 HNMR 进一步确定了依替巴肽分子的一级结构。结论:本文对依替巴肽的氨基酸序列以及一级结构全序列进行了确证。     

CONFORMATIONAL CHARACTERIZATION OF CYCLOPENTAPEPTIDE,LVAL-LPRO-GLY-LVAL-GLY: A REPEATING ANALOGUE OF ELASTIN

The cyclopentapeptide, ·L·Val¹-L· Pro²-Gly³-L· Val⁴-Gly⁵, was synthesized and its conformational characterization was carried out using n.m.r. and theoretical energy calculations. The n.m.r. studies indicated the existence of a cis Val¹-Pro² peptide bond in water and a very strong intramolecular H-bond between the Val¹ NH and Gly³ C=O groups. This H-bond forms a β-turn (type II) placing Val⁴ Gly⁵ residues within the turn. Two minimum energy conformations were derived, one of which agrees very well with the solution conformation.     

硫基氯试剂在双键加成和环化反应中的应用

综述了硫基氯试剂在合成环胺,内酰胺,内酯和环状氨基酸中的应用。苯硫基氯可由硫酚或二苯基二硫化物与硫酰氯或 N-氯代琥珀酰亚胺反应制得。     

Kinetic Investigation of the Condensation Reaction of Activated Ester–Amides Containing Oligo(oxyethylene) Segments

The kinetics of polycondensation of activated ester–amides, namely pentachlorophenyl α‐amino‐ω‐oligo(ethyleneglycol)succinate hydrochlorides (PSPnNH) having a degree of oligomerization n = 1–3, were investigated in solution in dichloromethane in the presence of excess triethylamine. The large extinction coefficient of the pentachlorophenate formed during the reaction allowed the use of the stopped flow technique. Experimental data resulted in agreement with the existence of concurrent first‐ and second‐order processes, attributable to the intramolecular cyclization and intermolecular polycondensation reactions, respectively. The relative incidence of the cyclization reaction decreased on increasing the monomer concentration and on decreasing the number of oxyethylene units in the monomer. These hypotheses were confirmed by SEC, TLC, FT‐IR, and NMR characterization of the reaction products. The kinetics of PSP3NH are in very good agreement with the predictions of both the collision theory and the condensation theory of linear systems at equilibrium. However, the behavior of shorter chain monomers was opposite to that of the theoretical one, demonstrating that other parameters, such as steric hindrance and solvent interactions, must be taken into proper account. The reported findings clearly evidenced that polymerization of the investigated ester‐amides must be performed in bulk in order to suppress the cyclization reaction and to obtain high‐molecular‐weight polymers.

SEC traces of PSP3NH condensation products obtained at different monomer concentrations (Runs P7–P9).     

3,5-二甲基-2-(3'''',5''''-二氟苯基)-2-吗啉醇盐酸盐的合成

目的：合成抗抑郁药安非他酮类似物3，5-二甲基-2-（3’，5’-二氟苯基）-2-吗啉醇盐酸盐。方法：以3，5-二氟苯丙酮为原料，经溴代、胺化、环合、酸化合成了目标产物。结果：合成目标产物的总收率为77．3％，中间体和产物经红外光谱和核磁共振谱确证。结论：以溴化铜为α-溴代反应溴化剂进行澳代反应，选择性高，产物易于分离。在非质子极性溶剂中进行胺化反应，反应时间短，溶剂无毒性，具有较高的应用价值。     

Facile Synthesis of Ladder‐Type Polyacenes with Perylene‐Fused‐Pyrene Structures

Ladder‐type polyacene (FP2) and model compounds (1c and 2c) with perylene‐fused‐pyrene structures are achieved in high yields by using a Pd(PPh₃)₂Cl₂‐catalyzed Suzuki reaction followed by cyclization with FeCl₃. The obtained model compounds and polyacene display desirable solubility in commonly used solvents and high thermal stability. Fluorescence peak at 614 nm is observed in diluted CH₂Cl₂ solution containing polyacene. Furthermore, the as‐prepared model compound (2c) and polyacene (FP2) are employed as acceptors in bulk‐heterojunction (BHJ) solar cells with PTB7‐Th as electrodonor cells. The 2c‐based solar cell demonstrates a power conversion efficiency of 3.25%.     

Polycondensations of Bisphenol‐A with Diphosgene or Triphosgene in Water‐Free Organic Solvents

Summary: Bisphenol‐A was polycondensed with diphosgene and excess pyridine in a mixture of dry dichloromethane and 1,4‐dioxane. The stoichiometry was varied to optimize the molecular weight. According to MALDI‐TOF mass spectra the fraction of cyclic polycarbonates increased with higher molecular weights. Analogous results were obtained with triphosgene. When pyridine was replaced by triethylamine, diethyl carbamoyl chloride was formed and an excess of diphosgene (plus triethylamine) yielded polycarbonates having one or two diethylcarbamate endgroups. However, the content of cycles increased again with the molecular weight and peaked for the sample with the maximum molecular weight. ¹H NMR endgroup analyses confirmed the interpretation of the MALDI‐TOF mass spectra. SEC measurement indicated high polydispersity indices (around 7) for samples rich in cycles.