Design, Synthesis, and Hypnotic Activity of Pyrazolo [1,5-a]pyrimidine Derivatives

On the basis of the Zaleplon structure, novel pyrazolo[1,5-a]pyrimidines were designed and prepared for studies on their hypnotic activity. This paper reported the synthesis of twelve new 5-methyl-7-substituted-pyrazolo[1,5-a]pyrimidine-3-carbonitrile derivatives by using simple starting materials such as propane dinitrile and triethyl orthoformate. The structures of the derived target compounds were confirmed by their IR and ^1H-NMR spectroscopic data. The preliminary pharmacological evaluations indicated that some compounds showed hypnotic activity, whilc derivative 1c was the most potent one.     

La和Nd在其氯化物熔体中的电化学腐蚀

稀土金属在其氯化物熔盐中的自腐蚀是导致电解制备稀土金属时电流效率降低的一个重要原因。但由于实验技术上的困难,有关这方面的研究报道不多。本文将在水溶液体系中常用的电化学弱极化测量腐蚀速度及电化学参数的方法用之于La、Nd在其氯化物熔盐体系中的腐蚀,表明同样适用。     

用3,6-双[(2-胂羧基苯)偶氮]-4,5-二羟基-2,7-萘二磺酰苯胺改性硅胶富集、分离痕量元素的研究

本文介绍了3,6-双[(2-胂羧基苯)偶氮]-4,5-二羟基-2,7-萘二磺酰苯胺(偶氮胂-DAL)改性硅胶的制备方法,研究了它的性质及其富集,分离Ti(Ⅳ),Zr(Ⅳ)、Hf(Ⅳ)的工作。研究结果表明,偶氮胂-DAL改性硅胶在6mol/L HClpH4.0的溶液中是稳定的;其对Zr(Ⅳ)的最大吸附量为20.9μmol/g;在1mol/L HCl介质中,经偶氮胂-DAL-SG柱预富集处理后,可将Zr(Ⅳ)、Hf(Ⅳ)与Ti(Ⅳ)、贵金属、常见过渡元素,稀土元素等金属离子直接分离,用普通分光光度法测定人工水样中Zr(Ⅳ)的下限可达10~(-9)g/g。     

11α-羟基-16,17α-环氧黄体酮的间接电解氧化

用媒质(Mediator)进行间接电解氧化有已许多报道与综述。该法与直接电解氧化法相比有以下优点:1.能在较低的电极电势下电解,从而既可抑制副反应;2.又可提高选择性(如媒质选择恰当);3.电流密度也可提高;4.底物在阳极不易产生树酯化;5.电流效率与化学收率高;6.媒质也可以循环再生利用等。     

THE INTEGRAL AS A FUNCTlON OF THE UPPER LIMIT AND DEPENDING ON A PARAMETER TO SOLVE DRAWING THROUGH IDLING ROLLS

ＴＨＥＩＮＴＥＧＲＡＬＡＳＡＦＵＮＣＴｌＯＮＯＦＴＨＥＵＰＰＥＲＬＩＭＩＴＡＮＤＤＥＰＥＮＤＩＮＧＯＮＡＰＡＲＡＭＥＴＥＲＴＯＳＯＬＶＥＤＲＡＷＩＮＧＴＨＲＯＵＧＨＩＤＬＩＮＧＲＯＬＬＳＺｈａｏＤｅ－ｗｅｎ（赵德文）；ＺｈａｏＺｈｉ－ｙｅ（赵志业）；...     

Iridoid glucosides from Allamanda neriifolia

<正>A new iridoid glucoside,allamanoid(1),was isolated from the aerial parts of Allamanda neriifolia,together with three known glucosides,plumieride,protoplumericin,and nicotiflorin.Their structures were elucidated by 1D and 2D spectroscopic analyses, hydrolysis,and comparison with literature data.     

Three new compounds from the leaves of Acanthopanax senticosus Harms

<正>Three new compounds named(2E)-prenyl benzoate-4-O-α-L-arabinopyranosyl(1→6)β-D-glucopyranoside(1),7-methoxy-8- O-β-D-glucopyranosyl coumarin(2),and 3,4'-dihydroxy-3'-methoxy benzenepentanoic acid(3) were isolated from the leaves of Acanthopanax senticosus Harms.The structures of new compounds were determined by means of 2D NMR experiments and chemical methods.     

A new dammarane-type triterpene saponin from Gynostemma pentaphyllum

<正>One new dammarane-type triterpene saponin,named(20S)-3β,20,21-trihydroxydammar-24-ene 3-O-[α-L-rhamnopyranosyl- (1→2)][β-D-xylopyranosyl(1→3)]-β-D-glucopyranoside(1),was isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino.Its structural elucidation was accomplished mainly on the basis of the interrelation of spectroscopic methods, such as IR,HR-TOF-MS,NMR.     

Ureido-modification of the resin-bound LHRH analogue with N,N''-carbonyldiimidazole

The ureido-modification of the resin-bound a luteinizing hormone releasing hormone (LHRH) analogue was investigated by CDI-activating method. The amino group at the side chain of LHRH analogue could be transformed into various substituted urea moieties in high yields. However, its terminal amino group was partially converted to a hydantoin structure due to the attack of the N atom of the adjacent amide bond.