银催化邻炔基苯甲醛腙合成多取代异喹啉偶极子

将含有不同取代基团的邻炔基苯甲醛腙化合物在乙酸银催化下,以二氯甲烷作溶剂,室温下自身发生环化反应合成N,N-异喹啉偶极子化合物。通过质谱(MS)、核磁共振波谱仪(NMR)等技术手段表征化合物的结构。考察了不同催化剂及其用量、原料配比、溶剂、温度对反应的影响。在最优条件下,反应收率为60%,在底物适应性上最高可达到85%。该方法具有操作简单,反应条件简单温和,产物收率高以及底物适用性好等优点。本文通过对实验条件、底物适用性等方面的探索,解决了以往合成异喹啉偶极子方法学中存在的多步进行、反应温度过高、底物适应性较低等不足与缺点,为制备含此类骨架的化合物提供了新的实验方法。     

N,N-二取代甘氨酸四乙酰基葡萄糖酯的合成与表征

在碳酸钾和十六烷基三甲基溴化铵存在下, 将N-(N-乙酰基-N-芳氨基乙酰基)-N-芳氨基乙酸与全乙酰化α-溴代葡萄糖反应合成出了7个新的N,N-二取代甘氨酸四乙酰基葡萄糖酯(5a～5g), 并利用IR, 1H NMR, MS和元素分析对其结构进行了表征.     

铜催化的α-氨基丙二腈的脱氰氧代反应：一种合成叔酰胺的新方法

新反应、新试剂的发展是有机合成化学的重要研究内容,基于前期在α-氨基丙二腈合成方法学方面的工作基础,我们发展了一例铜催化的α-氨基丙二腈的脱氰氧代反应.通过将甲酰胺转化为α-氨基丙二腈后,借助其亲核属性来合成α-氨基丙二腈底物,而后将底物重新转化为酰胺,从而实现形式上的氨基甲酰负离子的亲核加成(取代)反应.该工作首次完成了形式上的甲酰胺碳原子的极性反转,实现了将α-氨基丙二腈作为氨基甲酰负离子替代物的反应新模式,为叔酰胺化合物的合成提供了新的思路和方法,且具有反应条件简单,底物适用性广及适合克级规模制备等特点.     

非对映选择性合成威士忌内酯

报道威士忌内酯的非对映选择性合成，该合成路线包括5步反应，从巴豆酸甲酯出发制得重要中间产物3－甲酰基丁酯互，利用3－甲酰基丁酸甲酯的两个羟基与金属离子的螯合作用来控制其与正丁基溴化镁的加成反应，立体选择性地得到威士忌内酯，经气相色谱测定表明，产物反，顺异构体之比为92：8。     

Synthesis and Antimicrobial Activity of N,N-Disubstituted 3-Allyloxy-1-amino-2-propanethiols

3-Allyloxy-1,2-epithiopropane was synthesized; its treatment with amines yielded N,N-disubstituted 3-allyloxy-1-amino-2-propanethiols, which were tested for antimicrobial activity.     

Facile and Versatile Room-Temperature Synthesis of N,N-Disubstituted Cyanoacetamides from Malonic Ester Chloride

A general method for the synthesis of various N,N-disubstituted cyanoacetamides from readily available methyl malonyl chloride and secondary amines, including sterically demanding aliphatic and aromatic amines, is described.     

Reaction of ketenes with N,N-Disubstituted 2-Aminomethylenecycloalkanones III. Synthesis of N,N-Disubstituted 3,3-Diehloro-4-amino-5,6-polymethylene-3,4-dihydro-α-pyrones

The reaction of dichloroketene with N,N-Disubstituted 2-aminomethylenecyclopentanones, cyclohexanones, cycloheptanones and cyclooctanones gave the 1,4-cycloadducts, namely N,N-Disubstituted 3,3-dichloro-4-amino-5,6-polymethylene-3,4-dihydro-α-pyrones. The structures of these products were determined by uv, ir and nmr spectral data, as well as by dehydrochlorination of the adduct, 3,3-dichloro-4-diphenylamino-5,6-tetramethylene-3,4-dihydro-α-pyrone, which led to 3-chloro-4-diphenylamino-5,6-tetramethylene-α-pyrone. The by-product of the cycloaddition reaction was the N,N-Disubstituted dichloroacetamide, the formation of which varies according to the substituents on the nitrogen atom.     

Synthesis of Branched Hydrazones by Reaction of N-(2,3-Epoxypropyl) Derivatives of Hydrazones with Benzenediols

A series of branched hydrazones have been prepared by reaction of N-(2,3-epoxypropyl) derivatives of 9-ethyl-3-carbazolecarbaldehyde and 4-diethylamino-benzcarbaldehyde phenylhydrazones with 1,2-, 1,3-, and 1,4-benzenediols. It was found that the reaction rate depends on the polarity of solvents.     

Reactions of N,N-Disubstituted 5-Arylmethylidene-2-amino-thiazol-4(5H)-ones with CH Acids

Summary.  N,N-Disubstituted 5-arylmethylidene-2-aminothiazol-4(5H)-ones reacted with diethyl malonate, ethyl benzoylacetate, acetylacetone, or cyclopentadiene in refluxing toluene and in presence of powdered sodium to give the respective 5-arylmethylidene-2′-amino-2,5′-bithiazolylidene-4,4′-dione derivatives in moderate yields. 5-Benzylidene-2-morpholin-4-yl-2-thiazol-4(5H)-one reacted with malononitrile in toluene and in presence of powdered sodium under mild conditions to afford the 1:1 adduct, benzylmalononitrile, and 2-morpholin-4-yl-2-thiazol-4(5H)-one. However, similar treatment of 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-one with malononitrile yielded the 2,5′-bithiazolylidene-4,4′-dione derivative together with 4-methoxyphenylmethylidene malononitrile. Treatment of 5-benzylidene- and 5-(4-methoxyphenylmethylidene)-2-morpholin-4-yl-2-thiazol-4(5H)-ones with 3-phenyl-4-oxo-2-thioxo-1,3-thiazolidine in refluxing toluene and in presence of powdered sodium produced 5-arylmethylidene-3-phenyl-4-oxo-2-thioxo-1,3-thiazolidines in good yields. The structures of all products were deduced from microanalytical and spectroscopic data, mechanistic details are discussed. Corresponding author. E-mail: kamalkandeel@hotmail.com Received November 5, 2001. Accepted (revised) December 17, 2001     

The Synthesis of (3,5-DI-tert-butyl-4-hydroxyphenyl)methyl-(3-pyridylalkyl)-ethers via 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)methyl Pyridinium Salts.

The rearrangement of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)methyl pyridinium salts under basic conditions is described. A method for the synthesis of (3,5-di-tert-butyl-4-hydroxyphenyl)methyl-(3-pyridylalkyl)-ethers is elaborated.     

A New Synthetic Method for N-Mono- and N,N-Disubstituted Selenoamides

N-Mono and N,N-disubstituted selenoamides are synthesized in a one-pot procedure from nitriles, selenium metal and NaBH₄ followed by the amine group exchange of the intermediate primary selenoamide with an amine.     

Preparation and Characterisation of Bis (η5-Cyclopentadienyl) N,N-Disubstituted Dithiocarbamato Chloro Oxotungsten (VI) Complexes

Bis (η⁵-cyclopentaienyl) N,N-disubstituted dithiocarbamato chloro oxotungsten (VI) complexes of the type η⁵-Cp₂WO(S₂CNR₂)Cl and η⁵-Cp₂WO(S₂CNRR')Cl (where R=Me, Et and i-Pr and R'=Cyhx) have been prepared by the reaction of bis (η⁵-cyclopentadienyl) oxotungsten (VI) dichloride with sodium salts of dithiocarbamic acids in refluxing tetrahydrofuran. Infrared spectral studies demonstrate that in these complexes dithiocarbamate ligands are bidentate. Therefore, tungsten (VI) atom may be assigned a coordination number 6 in all these complexes. Elemental analyses of these compounds have also been carried out. Electronic spectra have been recorded for all the six complexes.     

Synthesis and Identification of New N,N-Disubstituted Thiourea,and Thiazolidinone Scaffolds Based on Quinolone Moiety as Urease Inhibitor

Synthesis of thiazolidinone based on quinolone moiety was established starting from 4-hydroxyquinol-2-ones. The strategy started with the reaction of ethyl bromoacetate with 4-hydroxyquinoline to give the corresponding ethyl oxoquinolinyl acetates, which reacted with hydrazine hydrate to afford the hydrazide derivatives. Subsequently, hydrazides reacted with isothiocyanate derivatives to give the corresponding N,N-disubstituted thioureas. Finally, on subjecting the N,N-disubstituted thioureas with dialkyl acetylenedicarboxylates, cyclization occurred, and thiazolidinone derivatives were obtained in good yields. The two series based on quinolone moiety, one containing N,N-disubstituted thioureas and the other containing thiazolidinone functionalities, were screened for their in vitro urease inhibition properties using thiourea and acetohydroxamic acid as standard inhibitors. The inhibition values of the synthesized thioureas and thiazolidinones exhibited moderate to good inhibitory effects. The structure−activity relationship revealed that N-methyl quinolonyl moiety exhibited a superior effect, since it was proved to be the most potent inhibitor in the present series achieving (IC₅₀ = 1.83 ± 0.79 µM). The previous compound exhibited relatively much greater activity, being approximately 12-fold more potent than thiourea and acetohydroxamic acid as references. Molecular docking analysis showed a good protein−ligand interaction profile against the urease target (PDBID: 4UBP), emphasizing the electronic and geometric effect of N,N-disubstituted thiourea.     

Liquid Chromatographic and Mass Spectral Analysis of N,N-Disubstituted 3,4-Methylenedioxyamphetamines

Abstract

The tertiary amine N,N-disubstituted derivatives of 3,4-methylenedioxyamphetamine (MDA) were prepared and their liquic chromatographic and mass spectral properties compared to other analogues of 3,4-methylenedioxyamphetamine. The N-methyl-N-ethyl, N-methyl-N-i-propyl and N-methyl-N-n-propyl MDA derivatives were separated in a reversed-phase system consisting of a C₁₈ stationary phase and a mobile phase of pH 4 phosphate buffer-acetonitrile (55:45). The mass spectral fragmentation of these amines is similar to that observed for the secondary amine MDA derivatives and can be used for their specific structural identification.     

Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2-Trifluoroethyl)arenes

Reacting hydrazones of arylaldehydes with Togni's CF₃-benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal-free.     

Synthesis of Novel Saccharide Hydrazones

Synthesis of important heterocyclic hydrazine derivatives N-aminopyrrolidine, N-aminopiperidine, and N-aminoazepane from hydrazine hydrate and dihalogenides were examined and optimized. These heterocyclic hydrazine derivatives were used in condensation reactions with six different monosaccharides to form corresponding hydrazones. Biological evaluations of these novel compounds, which are simple acyclic nucleoside analogs, were done. L-Arabinose N-aminoazepane hydrazone showed minor anti-HIV activity, giving a starting point for further structural modifications.     

二硝酸(N,N,N',N'-四正丁基丁二酰胺)合铀(Ⅱ)酰配合物的合成和结构

合成的配合UO~2[Bu~2NCO(CH~2)~2CONBu~2](NO~3)~2的晶体属四方晶系,a=b=3.3207(8),c=1.0711(4)nm,α=β=γ=90.00(0)°,V=11.811(7)nm^3,D~c=1.65g.cm^-3,Z=16,空间群为14~1/\α.配合物分子中铀酰离子由六个氧原子配位,其中四个来自两个硝酸根,另外两个来自有机配体的两个羰基,两个硝酸根被七原子环排斥而挤在一边,以铀原子为中心的六方双锥结构受到扭曲.