Rearrangement of 2—Benzothiazolylthioacetyl hidrazide in Ethanol Solution of Potassium Hydroxide：Synthesis of s—Triazolo[3,4—b] benzothiazol—3—thiol and Its Derivatives

A novel rearrangement reaction about 2-benzothiazolylthioacetyl hydrazide (1) to produce s-triazolo[3,4-b] benzothiazol-3-thiol (3) in the presence of KOH and CS2 was described.Other way to synthesize 3 from 2-benzothiazolyl-hydrazine (2) under the same condition was compared and the Mannich reaction of compound 3 was reported too.Their structures were established by elemental analyses,IR,^1H nmr and MS spectra.     

A New Solution—phase Parallel Synthesis of 2—Alkyamino—3—aryl—5—phenylmethylene—3,5—dihydro—4H—imidazol—4—ones

Thirteen new 2-alkylaminoimidazolones(4) wre rapidly synthesized by a new solution-phase parallel synthetic method,which includes aza-Wittig reaction of iminophosphorane(1) with aromatic isocyanate to give carbodi-imide(2) and subsequent reaction of 2 with various aliphatic primary amine in a parallel fashion.The products were confirmed by ^1H NMR,MS,IR and X-ray crystallographic analysis.The unusual selectivity of the cyclization was probably due to the deometry of the guanidine intermediate.     

Preparation of p—1,1,3,3—Tetramethylbutylphenol by Using Nafion—H Catalyst

p-1,1,3,3-Tetramethylbutylphenol was prepared by the alkylation of the phenol with Nafion catalyst in extremely high yield. Various reaction conditions were investigated, including the reaction temperature,reaction time, ratio of the starting material, amount of the Nafion catalyst and the recycle times of the catalyst.     

Studies on Hydroiodination and Deconjugation of 5—Aryloxy—（thiophenyl）—3—pentyn—2—one

One-pot hydroiodination and deconjugation of 5-aryloxy(or thiophenyl)-3-pentyn-2-one with a reagent system of sodium iodide/trimethylsilyl chloride/water in acetonitrile at 25℃ have been described.The plasuible mechanism was discussed.The reaction provided a simple and useful method for the preparation of (Z)-β-substituted β，γ-enones and (Z)-β-substituted α，β-unsaturated ketones.     

Synthesis of （1H）—3,4—Dithydropyrrolo[2,1—c][1,4]oxazin—1—one Derivatives

In search of new anti-inflammatory and analgesic agents,(1H)-3,4-dihydro-pyrrolo [2,1-c][1,4]oxazin-1-one(3) and its acyl derivatives were designed and prepared .Compound 3 was prepared by treatment of methyl 1-(2-bromoethyl) pyrrole-2-carboxylate with silver oxide and its derivatives were obtained by Friedel-Carftes reaction.Nine of 6-acyl derivatives of compound 3 were prepared.     

Synthesis and Crystal Structure of 2,5—Bis（morpholino）—3,4—bis（p—chlorophenyl）thiophene

1 INTRODUCTION -Thiocarbonylthioformamide synthesized in 1980[1, 2] is a class of stable and almost unexplored compounds[3]. We have reported the reaction of - thiocarbonylthioformamides in our previous paper[4]. Here, we will report a novel synthesis of 2 by the reaction of 1 and trimethyl phosphite in refluxing xylene. In order to determine the structure of 2, X- ray crystallographic study was carried out. 2 EXPERIMENTAL 2. 1 Preparation of the title compound Trimethyl phosph…     

A New Technique of Synthesizing 10—Hydroxy—5—methyl—5,10—dihydrophenophosphazine 10—Oxide

10-Hydroxy-5-methyl-5,10-dihydrophenophosphazine 10-oxide(1)was prepared by a new technique of treating 10-methoxy-5,10-dihydrophenophosphazine 10-oxide(2)with an equivalent of NaH in anhydrous DMF,and then at 120℃ for 3-4h,which not only avoided poisonous and expensive methyl iodide used in literature,but made the consumption of NaH greatly decrease as well.The possible reaction mechanism was also described.The chemical structure of 1 was confiremed by IR,NMR,and mass spectroscopy.     

Fragmentation Mechanism of Trans—α—Aryl—β—enamino Esters

Electron impact-induced fragmentation mechanism of Trans-α-Aryl-β-enamino esters were investigated using mass-analyzed ion kinetic energy (MIKE) spectrometry and high resolution accurate mass data It was found that the main characteristic fragmentations of compounds studied were:an odd electron ion M^ -EtOH was formed by losing a neutral molecule of ethanol;and the skeletal rearrangements took place;and the ring opening reaction happened after losing a carbon monoxide;and the typical McLafferty rearrangement underwent in ester group.The cycliztion reation caused by losing neutral molecule of TsNH2 due to the ortho-effects of substituted group of gromatic ring was also observed.     

Dramatic Solvent Effect in the Reduction of 2,3—Allenoic Acid Esters.A Simple Synthesis of 2,3—Allenols from 2,3—Allenoates

2，3－Allenols were prepared conveniently from the reduction reaction of 2,3-allenoates with DIBAL-H(Diisobutylaluminum hydride) in toluene.A dramatic solvent effect was observed for this reaction.     

Regioselective Bromination of 3,4—Dimethoxytoluene with N—Bromosuccinimide

The selective brominationsd of 3,4-dimethoxytoluene with N-bromosuccinimide were reported.The nuclear and side-chain brominated products were obtained under different reaction conditions.The mechanism was also discussed.     

溶液中甲醇和二氯亚砜的化学反应

用B3LYP方法和SCIPCM模型(模拟溶剂效应)研究了甲醇和二氯亚砜在两种非极性(ε<15)和两种极性(ε>15)溶剂中的反应(最终产物为氯代甲烷和二氧化硫). 反应过程由反应(1)和反应(2)组成, CH3OS(O)Cl是反应(1)的主要产物和反应(2)的反应物. 反应(2)有“前面取代”(经过渡态TS3f)和“背后取代”(先经CH3OS(O)Cl的电离, 再经过渡态TS3b)两种机理. 计算表明, 在气相和四种溶剂中反应(1)和(2)都是放热反应, 反应(1)具有相同的反应途径(经过渡态→中间体→过渡态), 溶剂的极性对反应(2)有很大的影响. 在气相和非极性溶剂中, TS3f的能量比(CH3OSO++Cl-)离子对(中间体IM2)的能量低, 反应(2)应为前面取代机理; 在极性溶剂中, IM2和TS3b的能量都比TS3f低, 反应(2)应为背后取代机理.     

SiO2在CH3ONO→CH3O+NO解离中作用的理论研究

利用B3LYP方法,在6-31 G^ 基组下研究了在SiO2存在下的CH3ONO→CH3O NO解离反应．计算了全优化下的解离反应,以及固定SiO2的键长和键角做部分优化下的解离反应．在反应中SiO2与CH3ONO相接近,O-N键逐渐伸长,生成复合物,放出热量,进一步促进了CH3ONO中NO的解离．     

阳离子光固化活性单体氧杂环丁烷的合成及表征

以3-乙基-3-羟甲基氧杂环丁烷为原料，与甲基磺酰氯磺酰化，得到3-乙基-3-甲磺酰基甲基氧杂环丁烷；在碱性条件下，以PEG600作相转移催化剂，用3-乙基-3-甲磺酰基甲基氧杂环丁烷与乙二醇醚化得到2-[（3-乙基-3-氧杂环丁基）甲氧基]乙醇；然后与甲基丙烯酸甲酯进行酯交换得到目的产物2-[（3-乙基-3-氧杂环丁烷）甲氧基]甲基丙烯酸乙酯。3-乙基-3-羟甲基氧杂环丁烷与3-溴丙烯反应，生成3-乙基-3-[（2-丙烯-1-基氧基）甲基]氧杂环丁烷，然后在氯铂酸的催化下，与三乙氧基硅烷反应得到3-乙基-3-[[3-（三乙氧基硅）丙氧基]甲基]氧杂环丁烷。产物经红外光谱和核磁共振谱表征得到确证。     

Highly selective hydrohalogenation reaction of substituted 2,3-allenoates

The hydrohalogenation reaction of 1-alkyl substituted 1,2-allenyl carboxylic acid esters (1) with MX (M= Na, or Li, X= Cl, Br, I) afforded a mixture of (5,7-unsaturated 3-halo-3-alkenoates (2) and α,β-unsaturated 3-halo-2-alkenoates (3) in HOAc, while using a mkture of HOAc-CF3CO2H (1:1) or CF3CO2H as the reaction medium the corresponding reaction cleanly produced β,γ-unsaturated 3-halo-3-alkenoates (2) as the sole products in high yields. The subsequent coupling reactions were studied.     

Ga2O3催化剂上CO2气氛中丙烷脱氢反应的研究

考察了Ga2O3对于丙烷脱氢和CO2气氛脱氢反应的催化性能,结果表明,Ga2O3具有较高的催化活性,其性能优于传统的Cr2O3脱氢催化剂,催化反应可能经过了一个丙烷异裂的过程,其中CO2是通过逆水煤气反应和Boudouard反应来促进催化剂性能的,在高于823K时该促进作用更为明显,催化剂的催化活性和其表面酸密度密切相关,在Ga2O3结构中,四配位Ga^3＋是其酸位的来源,并通过质子与氧化物的共同作用促进反应进行,催化剂的失活是由于表面的积碳和活性氧的消耗共同造成的,同时还对Ga2O3作为丙烷脱氢反应的催化剂的催化反应机理进行了初步探讨。     

Pt/Al2O3和Pt-Cu/Al2O3催化CCl4氢化脱氯反应

制备了Al2O3负载Pt单金属催化剂和负载Pt-Cu双金属催化剂,比较了二者不同还原温度对其催化CCl4氢化脱氯反应性能的影响。 单金属Pt催化剂上主要生成CHCl3,而双金属Pt-Cu催化剂上产物随催化剂制备时的还原温度不同而异,当催化剂经400 ℃用H2还原后产物主要为CHCl3,而当催化剂经800 ℃用H2还原后产物主要为CCl2CCl2。 由于CCl4氢化反应是强放热反应,催化剂表面局部过热使得在反应中生成的C2等产物聚合结焦,覆盖了催化剂的活性中心,导致催化剂失活。 因此,通过加入甲醇作为稀释剂以带走部分反应热可提高催化剂的稳定性。 同时也降低了CHCl3的选择性,提高了CCl2CCl2的选择性。     

CH_3自由基和O（~3P）反应机理的量子化学研究

用分子轨道从头计算MP2（full）方法和密度泛函理论（DFT）中的B3LYP方法 研究了CH_3自由基和三线态O原子反应的微观机理，优化得到了反应途径上的反应 物、过渡态、中间体和产物的几何构型，通过振动分析对过渡态和中间体构型进行 了确认，在G3不平上计算了能量，同时用经典过渡态理论对该反应的绝对速率常数 进行了理论计算。研究结果表明：CH_3自由基与O（~3P）反应有四条不同的放热反 应通道，主反应通道为IM1→TS1→CH_2O + H，同时反应可彻底裂解生成CO, H_2 及H。     

Rearrangement of 2-Benzothiazolylthioacetyl Hydrazide in Ethanol Solution of Potassium Hydroxide: Synthesis of s-Triazolo[3,4-b]benzothiazol-3-thiol and Its Derivatives

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三氯乙烷与氟原子的反应机理研究和速率常数计算

采用双水平直接动力学方法研究了反应CH3CCl3+F→CH2CCl3+HF的反应机理和动力学性质;在MPW1K/6-311+G(d,p)水平上优化了所有稳定点的几何构型,并通过频率分析进行了验证;随后在MCG3-MPWPW91//MPW1K水平上进行了能量校正,并利用变分过渡态理论,在MCG3-MPWPW91//MPW1K/6-311+G(d,p)水平上计算了反应在200～2 000K温度区间内的速率常数.结果表明,反应物CH3CCl3属于Cs点群,-CH3基团上的3个H原子等同,反应存在单个氢迁移反应通道.     

Selective Metallation of 3-Halothiophenes: Practical Methods for the Synthesis of 2-Bromo-3-formylthiophene

Selective lithiation of 3-bromothiophene was accomplished under controlled conditions without formation of undesired thienyllithium compounds. A thienyl Grignard reagent derived from 2-bromo-3-iodothiophene was transformed into 2-bromo-3-formylthiophene in high selectivity by formylation with dimethylformamide (DMF) at optimal reaction temperature.