Multicomponent Reaction for Synthesis of N-Arylsulfonyl Pyrazoles

A synthesis of functionalized N-arylsulfonyl pyrazoles from the multicomponent reaction of arylsulfonyl hydrazones and dialkyl acetylenedicarboxylates in the presence nucleophilic compounds such as pyridine, isoquinoline, or triphenylphosphine, in good yields, is described.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]     

Synthesis of Quinoline Derivatives by Multicomponent Reaction Using Niobium Pentachloride as Lewis Acid

The aim of this work was to investigate the use of NbCl₅ as a Lewis acid in multicomponent reactions between benzaldehyde, aniline derivatives and phenylacetylene in the synthesis of quinoline derivatives. The effects of the temperature and substituents in the aromatic ring of the aniline were also evaluated. The reactions were carried out at low concentration of niobium and in relatively short reaction times, resulting in yields ranging from 67 to 96%.     

Three-Component Reaction of Triphenylphosphine,Dimethyl Acetylenedicarboxylate,and Aldehyde Benzoylhydrazones: An Efficient One-Pot Synthesis of Stable Phosphorus Ylides

Protonation of the reactive 1:1 intermediate produced in the reaction between dimethyl acetylenedicarboxylate and triphenylphosphine by benzoylhydrazones leads to vinylphosphonium salts, which undergo Michael addition with the conjugate base of the NH acid to produce highly fanctionalized, salt-free phosphorus ylides in excellent yields.     

Synthesis of Ethylenetetracarboxylic Acid Derivatives

Summary. The three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylate and isocyanides with isocyanates is described. The reaction afforded the corresponding special type of ethylenetetracarboxylic acid derivatives in good yields.     

多组份一锅法合成新型2-取代噻唑-4-甲酸衍生物

以甲醇为溶剂,以醛、胺、硫代乙酸和3-(二甲氨基)-2-异氰基丙烯酸甲酯为原料,经四组份一锅法反应合成了9个新型的2-取代噻唑-4-甲酸衍生物,产率25%~54%,纯度90.3%~100%,其结构经1H NMR,13C NMR和LC-MS表征。     

三苯基锡与邻氨基苯甲酸型Schif碱配合物的合成及表征

合成了两种新的三苯基锡与邻氨基苯甲酸型Ｓｃｈｉｆ碱的配合物，经元素分析、ＵＶ、ＩＲ、１ＨＮＭＲ测定，对其结构进行了表征。结果表明，两种配合物具有不同的结构。在三苯基锡与水杨醛缩邻氨基苯甲酸Ｓｃｈｉｆ碱的配合物中，锡原子是六配位的，存在着酚羟基氧和亚氨基氮与锡的配键。在三苯基锡与２－羟基－１－萘醛缩邻氨基苯甲酸Ｓｃｈｉｆ碱的配合物中，锡原子是五配位的，酚羟基氧和亚氨基氮均未与锡配位，但存在着羰基氧与锡的配键     

氨基苯甲酸修饰的DTPA螯合物及其弛豫性能

用邻-、对-氨基苯甲酸修饰二乙三胺五乙酸(DTPA),分别得到两种分子中携带芳香基团的双酰胺型DTPA衍生物,合成了它们的顺磁性金属离子螯合物,并研究了其中部分螯合物的inuitroNMRT₁弛豫率(R₁).结果表明,Gd(Ⅲ)DTPA-B4ABA^2-和GdDTPA-B2ABA^2-对水质子的弛豫率R₁分别为5.5和5.4L·mmol^-1·s^-1,接近相应的母体螯合物GdDTPA^2-的R₁值5.2L·mmol^-1·s^-1.     

Multicomponent reactions involving zwitterionic intermediates for the construction of heterocyclic systems: one pot synthesis of aminofurans and iminolactones

The reaction of 1:1 zwitterionic intermediate generated in situ from dimethyl acetylenedicarboxylate (DMAD) and cyclohexyl isocyanide with aldehydes and quinones is described. The reaction of stoichiometric amounts of DMAD, isocyanide and aldehydes afforded 2-aminofurans in good yields, while the reaction with quinones gave iminolactones.     

Reaction of Dimethyl Acetylenedicarboxylate With 2-Mercaptoperimidine and 2-Mercaptobenzimidazole

A mixture of equimolar quantities of dimethyl acetylenedicarboxylate ( 2 ) with either 2-mercaptoperimidine ( 1 ) or 2-mercaptobenzimidazole ( 5 ) was heated in absolute benzene in the presence of triphenylphosphine as a catalyst under reflux conditions for 1 h (the reaction was monitored by TLC until the consumption of the starting materials). The solvent was concentrated under vacuum and the residue was subjected to chromatographic plates using toluene-ethylacetate (2:1) as an eluent. The products in each reaction were separated as two migrating zones. Each zone was removed from the plate and recrystallized from the appropriate solvent. The products of the first reaction are 10-methoxy-11-oxo-11H-8-thia-7,11a-diaza-benzo[de]anthracene-9-carboxylic acid methyl ester ( 3 ) and 8-thia-7,10a-diaza-cyclopenta[a]phenalene-9,10-dicarboxylic acid dimethyl ester ( 4 ), while the products of the second reaction are 3-methoxy-4-oxo-4H-1-thia-4a,9-diaza-fluorene-2-carboxylic acid methyl ester ( 10 ) and benzo[4, 5]imidazo[2,1-b]thiazole-2,3-dicarboxylic acid dimethyl ester ( 11 ). The mechanisms of the observed reactions are suggested.     

Palladium-Catalyzed Synthesis of Substituted Hydantoins—A New Carbonylation Reaction for the Synthesis of Amino Acid Derivatives

One-step synthesis of substituted hydantoins can be achieved by the palladium-catalyzed “ureidocarbonylation” of aldehydes with urea derivatives and carbon monoxide [Eq. (1)]. This surprisingly selective protocol converts substituted ureas into 1,5- and 1,3,5-substituted hydantoins in yields of up to 93 %.     

Synthesis of Betulonic Acid Derivatives Containing Amino-Acid Fragments

New derivatives of betulonic acid containing on C-28 fragments of amino acids or their methyl esters were prepared as potential biologically active agents.     

Reaction of diaryltriazenes with dimethyl acetylenedicarboxylate and PPh<Subscript>3</Subscript> as a method for synthesis of polyfunctional trisubstituted triazenes

A series of triazene derivatives with polyfunctional substituents, such as the ylide moiety and ester groups, were synthesized by the reaction of dimethyl acetylenedicarboxylate with 1,3-diaryl-1-triazenes in the presence of triphenylphosphine in ethyl acetate. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 512–514, March, 2007.     

Synthesis of Nicotinic Acid Derivatives by the Reaction of Salts of 1-Alkyl-4,6-dimethyl-2-pyrimidinylacetic Acid Esters with Amines

A study was carried out on the enamine rearrangement of iodoalkylates of the ethyl ester of 4,6-dimethyl-2-pyrimidinylacetic acid to give ethyl esters of 2-alkylamino-4,6-dimethylnicotinic acid, which proceeds upon the action of various amines. The reaction with amines containing an alkyl substituent different from that at the quaternized nitrogen atom of the pyrimidinium salt leads to the formation of products of rearrangement and transamination. In the presence of water, the rearrangement is accompanied by the formation of the ethyl ester of 1,2-dihydro-2-oxo-4,6-dimethylnicotinic acid.     

A Facile,One-Pot Synthesis of Azoic Compounds and Anthraquinone Derivatives Containing Dialkyl Phosphoryl Moieties in Multicomponent Reactions

Protonation of the reactive 1:1 intermediates produced in the reactions between triphenylphosphine and dialkyl acetylenedicarboxylates by 1-amino-anthraquinone or 1,5-diphenylcarbazone as a core dye leads to vinyl phosphonium salts, which undergo Michael addition with conjugate base of NH compounds to produce stable phosphorus ylides as novel dyes in fairly good yields. These ylides can exist in two geometrical isomers (Z) and (E) for 3, because the negative charge of the ylide moiety of these compounds are strongly conjugated with the adjacent carbonyl group. Rotation around the carbon–carbon double bond is slow in the (Z) and (E) geometrical isomers on the NMR time scale at ambient temperature. These compounds are assigned by their IR, ¹H, ¹³C NMR spectral data as well as their mass spectroscopic data.     

Stereoselective Synthesis of 1-Aminocyclopropanecarboxylic Acid Derivatives via Ylide Cyclopropanation of Dehydroamino Acid Derivatives

1‐Aminocyclopropanecarboxylic acid derivatives are synthesized from readily available dehydroamino acid derivatives via sulfur ylide. A range of different ylides are employed and the corresponding aminocyclopropanes are afforded with reasonable diastereoselection in good yields.     

Efficient,One-Pot Synthesis of Triazolothiadiazinyl-pyrazolone and Pyrazolyl-triazolothiadiazine Derivatives via Multicomponent Reaction

A one-pot, multicomponent reaction of 3-(2-bromo acetyl)coumarins, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and different derivatives of ethyl 2-(2-(aryl)hydrazono)-3-oxobutanoates provide an efficient and direct method for the synthesis of 4-(arylydrazono)-3-methyl-1-(6-(coumarin-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-1H-pyrazol-5(4H)-ones (4a–h). A similar methodology was also developed for the synthesis of pyrazolyl-triazolothiadiazines (9a–f) using acetyl acetone, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and different derivatives of phenacylbromide. The resulting products were characterized by analytical and spectral data.     

基于Ugi多组分反应的海藻酸酰胺衍生物改性二氧化硅纳米粒子的制备

采用海藻酸酰胺衍生物通过Ugi多组分反应制备了新颖的聚合物-二氧化硅(Oct-Alg-Si O_2)纳米粒子.通过氢核磁共振波谱(~1H NMR)和X射线光电子能谱(XPS)对Oct-Alg-Si O_2的结构和表面元素组分进行了表征.采用透射电子显微镜(TEM)、Zeta电位和激光粒度分析仪对Oct-Alg-Si O_2的形貌、粒径和胶体性能进行了探索.结果表明,海藻酸酰胺衍生物共价接枝到氨基二氧化硅(Si O_2-NH_2)纳米粒子的表面,提高了其平均直径,调控了其Zeta电位,在水介质中能够表现出良好的分散稳定性.以10%的液体石蜡为油相,采用Oct-Alg-Si O_2制备了Pickering乳液.在油水界面能够形成液滴粒径为5.7μm的稳定Pickering乳液.随着水相p H值的增大,乳液体积分数增大,稳定性增强.细胞相容性实验结果表明,Oct-Alg-Si O_2纳米粒子具有极好的生物相容性.     

新型2,4-二取代四氢吡咯-3-羧酸衍生物的合成

N-三甲硅甲基苯甲醛亚胺为非稳定型亚甲胺基叶立德前体,在磷酸催化下与取代噁唑烷酮烯烃经1,3-偶极环加成反应合成了10个具有cis-trans立体结构的新型2,3,4-三取代四氢吡咯-3-羧酸衍生物（3a~3j）,收率65%~75%,其结构经¹H NMR, ¹³C NMR和HR-MS表征。3b的立体结构经X-单晶衍射确证。