Hypervalent Iodine(III) Sulfonate Mediated Synthesis of Imidazo[1,2‐a]pyridines

A direct and efficient method for the conversion of alkyl aryl ketones to imidazo[1,2‐α]pyridines has been developed based on initial formation of α‐organosulfonyloxy ketones and their subsequent cyclocondensation by 2‐aminopyridines in one‐pot conditions.     

Synthesis of an Anti-1,3-Diol Type Chiral Building Block

Duringthelastdecade,1,3-dioltypechiralbuildingbIocksofvariousconfigurationshavebeensynthesizedandappliedwidelyinthetotalsynthesisofnaturalpolyenemacrolideantibiotics1'2andla,25-dihydroxyvitaminD3analogues'.RecentlyWeigandandBrucker4synthesizedachiralbuildingblock(4R,6R)-2,2-dimethyl-5-tert-butyldip4-hydroxymethyl-l,3-dioxane1inlOsteps.Herein,wereportasyntheticrouteofnewbuildingblock(4S,6S)-2,2-dimethyl-5-tert-butyldip2,anenantiomerofl,startingfromreadilyavailableandinexpensiveD( )-xylose3i…     

Pu（^7Fg）＋H2（X^1∑g^＋,0,0）的分子反应动力学

基于PuH_2分子基态(X~7A_1)的分析势能函数，用准经典的Monte-Carlo轨线法 对Pu(~7Fg)+H_2(X~1∑_g~+，0，0)的分子反应动力学过程进行了计算。结果表明 ：Pu(~7F_g)与H_2(X~1∑_g~+，0，0)碰撞是弹性碰撞。     

Synthesis of ansa -zirconocenes based on 2-(phenylethynyl)-1 H -indene. The crystal and molecular structure of the complex [μ-CH2CH2(η5-2-PhC≡CInd)2]ZrCl2 (Ind is inden-1-yl)

Alkynyl-substituted indene was first used as a ligand for the synthesis of transition metal complexes. ansa-Zirconocenes containing ethylene and dimethylsilylene bridges were synthesized starting from 2-(phenylethynyl)-1H-indene. The structure of the former compound was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68–73, January, 2007.     

~(19)F-NMR法测定聚醚多元醇中伯羟基的相对含量

<正> 聚醚多元醇是聚氨酯材料的主要原料之一.多元醇中伯羟基含量的多少对反应活性有着直接的影响,因此,准确地测定伯羟基含量已成为许多研究者关心的课题,并已报道了不少测定方法,其中主要包括化学动力学方法、~1H-核磁共振(NMR)法和~(19)F-NMR法,~1H-NMR法系利用不同的酰化剂,将聚醚多元醇酰化后测其酰化物的~1H-NMR谱,从伯、仲羟基相应的酯基氢的积分比例来计算伯羟基的相对含量,但由于体系中存在其它含氢基因,且是大量的,使测量困难或应用受到限制.~(19)F-NMR法测伯羟     

Synthesis and crystal structure of 4-acetoxy-5,6-dihydro-5,5-dinitro-2H-1,3-oxazineN-oxide

A novel heterocyclic compound, 4-acetoxy-5,6-dihydro-5,5-dinitro-2H-1,3-oxazineN-oxide, has been synthesized by the reaction of the dipotassium salt of 1,1,5,5-tetranitro-3-oxapentane with aqueous acetic acid. The synthesized compound has been studied by X-ray diffraction analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2207–2210, December, 1994.We would like to thank G. V. Lagodzinskaya (Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences) for recording and interpreting¹H NMR spectra, A. M. Korolev (Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences) for helpful discussion, and V. I. Fetisov (Institute of Physiologically Active Compounds, Russian Academy of Sciences) for performing quantum-chemical calculations by the AM1 SCF MO LCAO method.     

预富集电感耦合等离子体质谱法测定地下水中超痕量稀土元素及钪、钇

以P507萃淋树脂为固定相，HCl/EDTA为流动相，建立了地下水中超痕量稀土元素及钪、钇的ICP－MS测定的新方法。详细探讨了稀土元素（REEs）、Sc、Y与基体元素的分离、EDTA小体积洗脱的实验条件及ICP－MS工作参数。在pH2.6时上柱，大部分Ca、Mg，其体可不经淋洗而直接与REEs分离；以100mmol的EDTA洗脱，5mL淋洗体积REEs、Y、Sc回收率为96％－98.5%。详细考察了La、Ce、Pr的氧化物离子及氢氧化物离子的干扰及校正方法。分析方法的检测限为0.7-10.1ng/L，加标回收率为95％－99％。用于实际地下水及人工模拟水样的分析，结果令人满意。     

熔融萃取法富集痕量铂和铑─石墨炉原子吸收光谱测定

本文报道以２－硫基苯并噻唑（ＭＢＴ）为络合剂，用熔融萘萃取痕量的铂和铑，继用石墨炉原子吸收光谱法直接测定之。文中曾对一些有关参数作了试验，并找出各参数的最优值，对共存离子的允许量也作了试验。最后用国家标样和部级管理样核对本法，结果令人满意。     

2，6－二氨基吡啶与苦基氯的反应历程研究

对２，６－二氨基吡啶与苦基氯的反应历程进行了研究。通过二氨基吡啶与几种多硝基卤代苯的反应、溶剂效应、ＮａＦ的促进作用和紫外光谱吸收，证实该反应属于芳香族亲核取代反应类型，按加成－消除历程进行，反应过渡态涉及一个Ｍｃｉｓｅｎｈｅｉｍｅｒ络合物。     

HPLC－化学发光法测定痕量仲胺的研究

研究了测定仲胺的ＨＰＬＣ柱后化学发光检测的高灵敏分析方法。用Ｃ＿（１８）反相３μｍ色谱柱，乙腈＋水（６３．５＋３６．５）流动相，ｐＨ为６．５，对六种仲胺丹酰化衍生物实现了良好分离。研究了２－ＮＰＯ／Ｈ＿２Ｏ＿２体系的稳定性及发光条件。首次用这一体系检测了仲胺（亚硝胺的前体）。