N‐Nitrosation of Secondary Amines Using Supported Perchloric Acid on Silica Gel and Stereoselectivity Study of Nitrosated Products

N‐Nitrosation of different types of secondary amines has been proceeded using supported perchloric acid on silica gel and sodiume nitrite under heterogeneous conditions. The operational system is simple and high pure products can be easily isolated with good to high yields.     

Reaction of Elemol with Acetic Acid/Perchloric Acid: Characterization of a Novel Oxide and (+)‐β‐Cyperone

The minor unidentified compounds of the acetic acid/perchloric acid dehydration of elemol ( 1 ) were fully characterized. The structure and relative configuration of the less polar fragrant compound 2 , named elemoxide, was deduced by 1D‐ and 2D‐NMR data including C,C‐connectivity, NOE, and NOESY experiments. The absolute configuration was established as (3S,3aR,7aR)‐1,3,3a,4,7,7a‐hexahydro‐6‐isopropyl‐1,1,3,3a‐tetramethylisobenzofuran ( 2 ) on the basis of its preparation from elemol ( 1 ). (+)‐β‐cyperone ( 3 ), a known sesquiterpene, was also identified as a minor product of the reaction. A plausible mechanistic explanation for the formation of elemoxide ( 2 ) and (+)‐β‐cyperone ( 3 ) is presented.     

Efficient and Green Preparation of 2-Amino-4H-chromenes by a Room-Temperature,Na2CO3-Catalyzed,Three-Component Reaction of Malononitrile,Benzaldehydes, and Phloroglucinol or Resorcinol in Aqueous Medium

The preparation of substituted 2-amino-4H-chromenes by a Na₂CO₃-catalyzed reaction of malononitrile, benzaldehydes, and phloroglucinol or resorcinol in aqueous medium and at room temperature is reported. The merits of this procedure include limited use of organic solvents, easy workup technique, and high purity of products. The 2-amino-4H-chromenes were prepared in yields of 54–96%.     

三乙基苄基氯化铵(TEBA)催化下水中9-芳基多氢吖啶衍生物的合成

芳醛、5 ,5 二甲基 1,3 环己二酮与醋酸铵在三乙基苄基氯化铵 (TEBA)催化下以水作为溶剂反应 ,生成一系列 3 ,3 ,6,6 四甲基 1,8 二氧代 9 芳基 1,2 ,3 ,4,5 ,6,7,8,9,10 十氢吖啶 ,与其它溶剂相比 ,水作为该反应的溶剂具有价格便宜 ,不易燃和无毒等优点 ,而且产率较高 ,产物的结构通过单晶X射线确证     

An Efficient and Green One‐pot Synthesis of 12‐Aryl‐8,9,10,12‐tetrahydrobenzo[a]xanthen‐11‐one Derivatives Promoted by Sulfamic Acid in [BMIM]BF4 Ionic Liquid

An efficient and green procedure for the synthesis of novel 12‐aryl‐8,9,10,12‐tetrahydrobenzo[a]xanthen‐11‐one derivatives has been described through one‐pot condensation of 2‐naphthol, arylaldehyde and 5,5‐dimethyl‐cyclohexane‐1,3‐dione in the presence of sulfamic acid (NH₂SO₃H) in ionic liquid 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIM]BF₄). These reactions proceed with good yields under short reaction time. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.     

Studies on the Total Synthesis of Crotocembreneic Acid and Neocrotocembreneic Acid:A Perchloric Acid-induced Lactonization Reaction of Epoxy Ester

Cembranoids, a large family of diterpenoid natural products characterized by the presence of fourteen-membered ring, have been isolated from various marine sources as well as some terrestrial organisms since the 1960's1. Crotocembraneic acid 1 and neocrotocembraneic acid 2 have been isolated from the stem bark of Croton oblongifolius Roxb. (Euphorbiaceae)2. In our studies on the total synthesis of 1 and 2, we find a novel perchloric acid-induced lactonization reaction of epoxy ester 9 (Scheme…     

3,6-二甲基-9-芳基-1,8-二氧代-2,7,10-三氧杂蒽的合成及晶体结构

以芳醛、6 甲基 4 羟基 2 吡喃酮为原料 ,醋酸酐为溶剂合成了一系列 3 ,6 二甲基 9 芳基 1,8 二氧代 2 ,7,10 三氧杂蒽 ,产物的结构经红外、核磁、元素分析及X射线衍射法表征 ;并对反应过程提出了可能的机理     

3,6-双(1氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪的合成与表征

研究了低感度高氮化合物3,6-双(1氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪的合成,其结构经元素分析,IR,^1H NMR和^13C NMR表征。     

PMAA纳米水凝胶的水相制备

利用表面活性剂间的疏水作用以及表面活性剂与单体间的氢键作用,促使甲基丙烯酸(MAA)单体在原位生成的聚甲基丙烯酸甲酯(PMMA)种子乳胶表面的选择性聚合,实现了PMAA纳米水凝胶的水相"绿色"制备。利用动态光散射、傅里叶红外光谱、透射电子显微镜表征了PMAA纳米水凝胶的尺寸、组成、形貌和pH响应性。研究了聚氧乙烯失水山梨醇单月桂酸酯(吐温20)的用量、N,N’-亚甲基双丙烯酰胺(MBA)的用量、MAA的用量和加入方式、十二烷基硫酸钠(SDS)的补加速率等对PMAA纳米水凝胶的尺寸和溶胀性能的影响。结果表明:PMAA纳米水凝胶为核-壳结构;随着MBA用量的减小、吐温20用量的增加、MAA用量的增加,PMAA纳米水凝胶的尺寸和溶胀比均增大;当采用半连续加入MAA时,PMAA纳米水凝胶的尺寸和溶胀比变小;当SDS的补加时间由60min延长到100min时,PMAA纳米水凝胶的尺寸逐渐变小。PMAA纳米水凝胶具有良好的pH响应性,当介质的pH从1增加到6时,其流体力学体积扩张了64倍。     

Microwave-Assisted One-Pot Synthesis of 3-Amino-1-aryl-8-bromo-2,4-dicyano-9H-fluorenes in Water

A series of novel 3-amino-1-aryl-8-bromo -2,4-dicyano-9H-fluorenes derivatives were prepared using arylaldehyde, 4-bromo-indanone, malononitrile, and sodium hydroxide as the reactants in water via one-pot synthesis under microwave irradiation. A green and efficient method was successfully developed via microwave irradiation. The method possesses several advantages, such as environmental friendliness, shorter reaction time, and simple workup procedure.      

水相中磷钼酸催化三组分合成烯丙基胺

以磷钼酸作为催化剂，芳香醛、胺和三丁基烯丙基锡三组分在水作为溶剂，室温下高产率的得到相应的烯丙基胺。     

Synthesis and degradabilities of polyesters from 1,4:3,6-dianhydrohexitols and aliphatic dicarboxylic acids

Six different polyesters ( 6a–6c and 7a–7c ) were prepared by the bulk polycondensations of the respective combinations of 1,4:3,6-dianhydro-D-glucitol ( 3 ) and 1,4:3,6-dianhydro-D-mannitol ( 4 ) with succinyl dichloride ( 5a ), glutaryl dichloride ( 5b ), and adipoyl dichloride ( 5c ) at 140–180°C. Polyesters having number average molecular weights up to 2.6 ×10⁴ were obtained in high yields. Only polyester 7a based on 4 and 5a was partially crystalline, whereas all the other polyesters were amorphous. Thin films of these polyesters except that of 7a were spontancously hydrolyzed in a neutral phosphate buffer solution at 50°C, whereas they were reluctant to be hydrolyzed at 27°C. The polyesters were more or less degraded at 27°C by treatment with an activated sludge or by prolonged burial in soil. © 1995 John Wiley & Sons, Inc.     

Synthesis and Crystal Structure of 3,6-Bis(4,4,4-trifluorobutane-1,3-dione)-9-n-butylcarbazole

A novel bis(β-diketonate) derivate, 3,6-bis(4,4,4-trifluorobutane-1,3-dione)-9-n- butylcarbazole 1, was synthesized and structurally characterized by single-crystal X-ray diffrac- tion. The crystal belongs to the monoclinic system, space group P21/c with a = 10.961(6), b = 22.942(13), c = 9.408(6) , α = 90, β = 109.663(9), γ = 90o, V = 2228(2) 3, Z = 4, Dc = 1.489 g/cm3, C24H19F6NO4, Mr = 499.40, F(000) = 1024 and μ = 0.134 mm–1. The structure was refined to the final R = 0.0699 and wR = 0.1627 for 3744 independent reflections (Rint = 0.1288) and 1349 observed reflections (I > 2σ(I)). Compound 1 consists of carbazole unit and two terminal diketonate groups, in which carbazole and its two adjacent diketonate rings are almost coplanar. Moreover, compound 1 was characterized with IR, elemental analysis, 1H NMR, MS, electronic absorption, and single-photon fluorescence.     

蜜蜂外激素9－ODA和9－HDA的合成

６－溴－２－己酮在Ｌｉ２ｃｕＣｌ４催化下与γ－溴代巴豆酸甲酯进行格氏偶联，合成了蜂王物质９－羰基－（Ｅ）－２－癸烯酸（９－ＯＤＡ），将其还原得到另一蜂王物质９－羟基－（Ｅ）－２－癸烯酸（９－ＨＤＡ）。该法是合成９－ＯＤＡ和９－ＨＤＡ的新路线。     

接枝环氧树脂水分散液的合成、分离与表征

控制不同的反应条件,采用甲基丙烯酸、苯乙烯与环氧树脂在丙二醇丁醚/正丁醇溶剂中接枝共聚,合成了粒径在87～104nm范围的环氧树脂水分散液。通过环己烷/乙醇和丙酮两步萃取,对接枝共聚产物进行分离,用FTIR表征,并估算了接枝共聚物的组成。实验结果表明,所制备的粒径为纳米级的环氧树脂水分散液,具有良好的机械稳定性、冻融稳定性及贮存稳定性。ξ电位测定表明,产物在pH>8的条件下更为稳定。     

Perchloric Acid–Silica (HClO4⋅SiO2)‐Catalyzed Synthesis of 14‐Alkyl‐ or 14‐Aryl‐14H‐dibenzo[a,j]xanthenes and N‐[(2‐Hydroxynaphthalen‐1‐yl)methyl]amides

The synthesis of 14‐aryl‐ or 14‐alkyl‐14H‐dibenzo[a,j]xanthenes 3 involving the treatment of naphthalen‐2‐ol ( 1 ) with arenecarboxaldehydes or alkanals 2 in the presence of HClO₄?SiO₂ as a heterogeneous catalyst was achieved (Table 1), and this reaction was extended to the preparation of N‐[(2‐hydroxynaphthalen‐1‐yl)methyl]amides 5 by a three‐component reaction with urea ( 4a ) or an amide 4b – d as a third reactant (Table 2).     

Synthesis, characterization and quantum chemistry study of 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine

3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)- 1,2,4,5-tetrazine (BTATz) was synthesized by the condensation of triaminoguanidinium nitrate with 2,4-pentanedione, followed by oxidation and substitution reaction. The product was characterized by elemental analysis, IR, NMR spectrometry and DSC analysis. Instead of nitrogen dioxide/N-methylpyrrolidone, acetic acid/sodium nitrite was used as the oxidizer during the oxidation. Thus, the cost was reduced and the process was simplified. The theoretical properties of BTATz were estimated by a B3LYP method based on a 6-31G(d,p) basis set, and the stable geometric configuration and bond order were obtained. The vibrational frequencies, IR spectrum and thermodynamic properties under different temperatures were obtained from vibrational analysis and the relationship between temperature and thermodynamics properties was deduced. Pyrolysis mechanism of BTATz was discussedand the transition state and activation energy of ring opening reaction of the tetrazole were deduced. __________ Translated from Chinese Journal of Organic Chemistry, 2008, 28(3) (in Chinese)     

水中N-羟基吖啶衍生物的一步合成

N-Hydroxylacridinedione derivatives were synthesized by three-component reaction of aromatic aldehydes, 1,3-dicarbonyl compounds and hydroxylamine hydrochloride using triethylbenzylammonium chloride （TEBA） as the catalysis in water. The reaction has many advantages including good yields, easy to be separated and environmental friendliness.     

3,6-二甲基-9-对硝基苯基-1,8-二氧代-2,7,10-三氧杂蒽的合成和晶体结构

标题化合物C19H13NO7 是由对硝基苯甲醛, 6-甲基吡喃酮在微波辐射下反应而得, 反应在五分钟内完成。结构通过单晶 X-射线衍射法测定, 其晶体属单斜晶系,空间群P21/c, a = 10.669(1), b = 11.544(1), c = 14.045(2) ? b = 105.98(1) , V = 1663.0(3) ?, Mr = 367.30, Z = 4, Dc = 1.467g/cm3, l = 0.71073 ? m(MoKa) = 0.114 mm-1, F(000) = 760, R = 0.0380, wR = 0.0944。在分子结构中存在一个大的共轭体系。     

水溶液中一步合成二吡咯甲烷类化合物

在水相中,以磷钨酸为催化剂,吡咯与羰基化合物为底物,室温下一步合成了二吡咯甲烷类化合物,反应产物纯度高,无需进一步纯化.该方法具有明显的环境友好、产率高和操作过程简便的优点.