Structural and conformational study of ortopramides derived of the tropane system

Several 3(substituted benzamido)N-substituted-nortropane compounds have been synthesized and their molecular structures determined by IR, ¹H NMR and ¹³C NMR methods. From the IR data a molecular association was deduced for these compounds in the solid state. From the ¹H NMR and ¹³C NMR, the following general features were deduced: All compounds studied adopt a slightly flattened chair conformation in CDCl₃ or DMSO solution. In all cases, only the epimer with the amido group in the exo position was isolated.     

13C NMR spectroscopic studies of the behaviors of carbonyl compounds in various solutions

¹³C NMR spectroscopic studies were performed for carbonyl compounds having a hydroxyl group, a carboalkoxy group, an acetoxy group, or a carboxyl group in various solvents with different polarities for observation of their behaviors of ¹³C NMR chemical shifts of carbonyl carbons in solutions. It was found that the chemical shifts of the carbonyl carbons in ¹³C NMR have good correlation with the empirical parameter for solvent polarities, E_T^N, depending on the structures. Inter- or intramolecular hydrogen bonding and dipolar-dipolar interactions appear to play a key role in this observation.     

酰基硫脲衍生物的合成、结构表征及生物活性研究

在超声波辐射下, 以PEG-400为固-液相转移催化剂, 用芳胺与双酰基异硫氰酸酯反应, 合成出了15种新的结构不对称的双酰基硫脲类化合物(6和6')和9种新的分子中含酰胺基团的单酰基硫脲类化合物(7和7'). 利用元素分析, IR, ¹H NMR, ¹³C NMR, APT, 1D NOE及2D NMR技术确定了所合成化合物6和6'及7和7'的结构, 并对它们NMR谱中低场C, H进行了归属. 杀菌、杀虫和除草活性筛选测定实验结果表明, 所测试化合物对瓜炭疽病菌均具有抑制作用, 其中6e抑制率最高, 达到62.4%; 目标化合物7a对黄瓜白粉病菌有一定的抑制作用. 单胺氧化酶活性测定实验表明：大部分目标化合物对单胺氧化酶具有一定的抑制活性, 其中浓度在1×10^－3 mol•L^－1时目标化合物6'c和6'd的抑制活性较强, 明显高于其它化合物. 目标化合物没有抗惊厥活性.     

Synthesis of saccharidyl N,N-bis(2-chloroethyl)phosphoramidates and their antitumor activity

In order to search for novel antitumor drugs with high activity and low toxicity, a series of new compounds, galactopyranosyl (or glucofuranosyl) N,N-bis(2-chloroethyl) phosphoramidates, have been synthesized. The structures of all compounds prepared were proved by ¹H NMR, ³¹P NMR, IR, and MS spectroscopy and by elemental analyses. The existence of diastereoisomers was detected by ³¹P NMR and ¹H NMR spectra. One of the two isomers of 3a and also one of 4b , i.e., 3a′ and 4b′ , respectively, were obtained by recrystallization. The absolute configurations of 3a′ and 4b′ were determined by single-crystal X-ray diffraction analysis. The results of the preliminary biological tests indicated that some of these compounds have certain inhibitory activities against L₁₂₁₀ cells.     

Preparation and 31P NMR spectra of N-thiocyanato derivatives of some organophosphorus(III) halides

The compounds RP(NCS)₂ (R = Ph, Me, Et or C₆F₅) have been prepared, and ³¹P NMR data have been recorded both for them and for their precursors RPX(NCS) (X = Cl or Br). They are all thermally unstable, particularly the alkylphosphorus compounds, thus accounting for some discrepancies with literature NMR data. The NCS group has been shown to be N-bonded in each instance by means of IR spectroscopy.     

The synthesis of new cyclic thioquinone derivatives

New bis(thio)substituted, S‐,O‐substituted, and S‐,S‐substituted benzoquinone compounds were synthesized from the reaction of p‐chloranil ( 1 ) with S‐,O‐substituted thiols, dithiols, and monothiols. The ¹³C NMR spectra and the IR spectra of heterocyclic compounds 3 , 4 and 7 , 8 showed different behavior; that of 3 , 7 showed a carbon signal and a >CO group band for the carbonyl group and that of 4 , 8 showed two carbon signals and split bands for the carbonyl group. The structures of the novel compounds were characterized by microanalysis, FT‐IR, ¹H NMR, ¹³C NMR, MS, and UV–vis spectroscopy. The crystal structure of 2,3,5,6‐tetrakis(4‐fluorobenzylthio)cyclohexa‐2,5‐diene‐1,4‐dione ( 15 ) was determined by the X‐ray diffraction method. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:446–452, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20634     

One Pot Synthesis of Some New Heteroylselenoglycolic Acids and Their Biological Activity

Abstract

A convenient one pot three-stage synthesis was used for obtaining new heteroylselenoglycolic and di-heteroylselenoglycolic acids by nucleophilic substitution reaction of the starting compounds pyridineselenol, pyridazineselenol, and quinolineselenol with α-chloro- or α,α-dichloroacetic acids for 1-h stirring. The newly synthesized compounds were screened biologically for anti-microbial and anti-oxidant activities. The structure of all new compounds was confirmed by ¹H NMR, ¹³C NMR, Mass, and IR spectroscopy and elemental analyses.     

Synthesis of Polysubstituted‐1,2,4‐Triazoles

A new series of substituted 1,2,4‐triazole derivatives have been synthesized using substituted imido derivatives and isonicotinyl hydrazine (or 4‐nitrobenzoylhydrazine) as the key intermediates. These compounds include different donor or acceptor substituents on the 1,2,4‐triazole derivatives. The structures of these compounds were confirmed by FTIR, ¹H‐NMR, ¹³C‐NMR, and elemental analysis.     

One-pot multicomponent synthesis of indol-3-yl-hydrazinyl thiazoles as antimicrobial agents

A series of novel mono- and bis(indol-3-yl)hydrazinyl thiazole derivatives were efficiently synthesized via one-pot cyclocondensation of mono- or bis(indole-3-carbaldehyde), thiosemicarbazide, and phenacyl bromides. The structure of the products was confirmed by Fourier-transform infrared (FT-IR), ¹H nuclear magnetic resonance (NMR), and ¹³C NMR spectra. All synthesized compounds were evaluated for in vitro antibacterial activity against Gram-positive (Bacillus subtilis and Micrococcus luteus) and Gram-negative bacteria (Pseudomonas aeruginosa and Salmonella enteritis). Among the compounds screened, a few were found to be highly effective antibacterial agents. The bis-compounds with OCH₃ donating group exhibited good activity against the Gram-positive bacteria.     

合成硅氧醚的新方法：Silyltriflimides与醇或与醚反应

首次利用silyltriflimides［双－（三氟甲磺酰）－亚胺基硅烷］与醇或醚反应合成了一系列非环链状或环状的硅氧醚,反应产率较好。其中反应物silyl triflimides很容易由相应的苯基硅烷或丙烯基硅烷与HNTf2通过质子脱硅化反应得到。合成的新化合物的结构用1H NMR, 13C NMR, MS, IR 和HRMS等进行了表征.     

Synthesis and insecticidal activity of 6,8-dichloro-quinazoline derivatives containing a sulfide substructure

A series of 6,8-dichloro-quinazoline derivatives bearing a sulfide group was synthesized and characterized via ¹H NMR, ¹³C NMR, IR and elemental analyses. All the compounds were tested for their insecticidal activity against Plutella xylostella in vitro. The results indicate that the synthesized compounds possess good insecticidal activity. Among these compounds, Vc, Vi, Vj, Vk and Vm displayed 75 %, 85 %, 80 %, 70 % and 63 % activities, respectively. These may prove useful as insecticidal agents.     

穿心莲中两个黄酮苷的波谱学研究

研究了穿心莲中抗血栓的活性成分. 应用AB-8大孔吸附树脂、聚酰胺柱色谱及薄层色谱进行分离, 应用波谱学(¹H NMR, ¹³C NMR, DQFCOSY, TOCSY, HMQC, HMBC, NOESY等)方法进行结构鉴定. 分离得到两个黄酮苷类化合物, 确定了¹H NMR, ¹³C NMR信号的全归属. 化合物1鉴定为5,4'-二羟基-7-甲氧基黄酮-6-O-β-D-葡萄糖苷, 化合物2鉴定为5,4'-二羟基-7-甲氧基黄酮-8-O-β-D-葡萄糖苷, 化合物1为首次从该植物中分得, 首次对两个化合物的碳谱和氢谱进行了全归属.     

Synthesis,characterization and catalytic properties of cationic N-heterocyclic carbene silver complexes

Three new dibenzimidazolium salts bridged by 2-methylenepropane-1,3-diyl group were synthesized. Their dinuclear N-heterocyclic carbene Ag(I) complexes were prepared by the reactions of these salts with Ag₂O. The structures of the synthesized compounds were defined by nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), elemental analysis, and LC-MSMS (for complexes) techniques. Stability of the silver complexes was confirmed by ¹H NMR spectroscopy. Catalytic activities of Ag(I) compounds were tested for three-component coupling reaction of some aldehydes, amines, and phenylacetylene.     

The investigation of the electronic effects of polyfluoro-aryl group by means of nmr spectroscopy

The relationship between NMR ¹⁵N, ¹⁷O, ³¹P, ⁷⁷Se, ¹³C spectral parameters and electronic structure of number of polyfluoroaromatic compounds has been discussed. The increase of the nuclei shielding has been found in all classes of investigated polyfluorinated compounds in respect to the corresponding hydrocarbon analogues. That effect has been discussed in terms of decrease of the conjugation between the unshared electron density of heteroatoms and the π-system of polyfluorinated benzene ring. The conductivity of substituent electronic effects on the π-system of the polyfluoroaryl group by the heteroatom has been estimated from NMR ¹³C data. The sensitivity of nuclei shielding towards interamolecular electronic effects has been noticed to increase from oxygen to selenium and the analysis of the influence of the intramolecular electronic effects on the ¹⁷O and ⁷⁷Se shifts has been given. The influence of the substituents either in pentafluorophenyl ring or adjacent to heteroatom have been shown to correspond those in the hydrocarbon analogues.The conclusion about the influence of polyfluoroaryl group on the character of bonds between different atoms in functional group has been made from the NMR ¹⁷O and ¹⁵N data for aromatic nitro-derivatives. Polyfluorophenyl group in respect to phenyl one deshields the oxygen atom and shields the nitrogen atom. The same effect of pentafluorophenyl group has been observed by other spectral methods.The different screening of ¹⁷O, ¹⁵N, ³¹P and ⁷⁷Se nuclei due to the action of substituents adjacent to the element and variation of the coordination number of heteroatom have been used to the solvation of a number of problems in chemistry of the heteroanalogues of carbenium ions and the detail investigation of the mechanism of electrophylic substitution in the field of polyfluoroaromatic compounds.     

Synthesis and biological studies of some new acrylic acid ethyl esters of quinolinone

Abstract  

A series of new acrylic acid ethyl esters of quinolinones were synthesized from 4-(bromomethyl)quinolinones and screened for in vitro antimicrobial and in vivo analgesic and anti-inflammatory activities. Most of the compounds with chloro substitution at the C-6 or C-7 position in the quinolinone moiety and a methoxy group in the aryloxy moiety showed potent antibacterial and antifungal activities when compared with non-halogenated quinolinones and the quinolinones bearing a CH₃ at the C-8 position. In a pharmacological evaluation, the halogen substitution at the C-6 or C-7 position in quinolinones was found to enhance both analgesic and anti-inflammatory activities of the molecule when compared with a simple unsubstituted (non-halogenated) quinolinone. The structures of all newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and FAB-MS.     

焦脱镁叶绿酸的Knoevenagel反应及其杂环取代衍生物的合成

以焦脱镁叶绿酸-d甲酯(MPPd)为起始原料, 通过其醛基与连有五元杂环的β-二酮、α-氰基酮和丙二腈的活性亚甲基进行Knoevenagel反应, 完成3-位五元杂环取代的焦脱镁叶绿酸-a甲酯衍生物. 所合成的新化合物均经UV, IR, ¹H NMR及元素分析证明其结构.     

Synthesis and Complexation Behavior Studies of Novel Bis-crown Ethers

The novel unique structures of bis-crown ethers were successfully synthesized from tri (propylene glycol) di-acrylate with amino- and aza-crown ethers through Michael addition. The crown ethers contained the primary and the secondary amine group such as 2-aminomethyl crown ethers, 4-aminobenzo crown ethers and 1-aza crown ethers. The newly synthesized bis-crown ethers were characterized by elemental analyses, IR, ¹H NMR, ¹³C NMR, mass spectrum, respectively. The newly synthesized host compounds of bis-crown ethers showed complex ability with various sizes of alkali metal cations such as Na⁺, K⁺, Rb⁺ and Cs⁺. The complexation behavior was examined by ¹H NMR spectroscopy and UV spectrometry.     

Synthesis and mesomorphism study of star‐shaped carbohydrate liquid crystals containing glucosyl and glutamyl residues

A series of novel star‐shaped carbohydrate derivative liquid crystals was synthesized with glucose as the chiral core structure. Glutamyl mesogenic moieties, l‐R‐{n‐[4‐(cholesteryloxycarbonyl)benzoyloxy]alkoxy}glutamic acid, were introduced to the five hydroxy groups of glucose by direct esterification. The chemical structures of the target liquid crystalline compounds were confirmed by element analysis and Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy. The mesomorphic behaviour and thermal properties of target liquid crystalline compounds were investigated with differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, X‐ray diffraction and specific rotation. All the target compounds exhibit a cholesteric liquid crystalline phase. These compounds demonstrate a wide mesogenic region and high thermal stability. The effect of flexible spacer group length of the target compounds on the molecular structure and thermal properties is discussed.     

Wide- and narrow-rim functionalised calix[4]arenes: synthesis and characterisation

Functionalisation of calix[4]arene at both the wide and narrow rims leads to the formation of compounds containing bipyridyl, via an amide linkage, at the wide rim and having either a butyl chain, a benzyl group or an alkyl ester functionality at the narrow rim. All compounds were characterised using ¹H and ¹³C NMR spectroscopies. Initial binding studies with Ru(bipy)₂Cl₂ are reported.