Reaction of Malonic Acid Derivatives with Acetylenic Diphosphonates

The primary addition products in the reactions of malonic esters, cyanoacetic esters, and malononitrile with acetylenediphosphonates in acetonitrile in the presence of anhydrous potassium carbonate are potassium derivatives, viz. esters and nitriles of the corresponding 2-alkoxycarbonyl(or 2-cyano) -3,4-bis(di-alkoxyphosphinoyl)-2-potassiobut-3-enoic acid. Further hydrogen replacement for potassium in the nitriles is accompanied by isomerization involving double-bond shift and geometry change. (E)- and (Z)-3,4-bis(dial-koxyphosphinoyl)-2-cyano-2-potassiobut-3-enenitriles (the alkoxy groups are CH₃O and C₂H₅O) are crystalline compounds; they were isolated and characterized.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 1, 2005, pp. 11–20.Original Russian Text Copyright © 2005 by Shekhadeh, Didkovskii, Dogadina, Ionin.     

Reaction of 3-Methyleneisocamphanone with Derivatives of Malonic Acid

Reaction of 3-methyleneisocamphanone with malononitrile, ethyl cyanoacetate or diethyl malonate in the presence of catalytic quantities of alkali or under catalysis with tetramethylguanidine in ethanol proceeds according to classical scheme of the Michael reaction and gives rise to 3-exo-(2,2-dicyanoethyl)-, 3-exo-(2-cyano-2-ethoxycarbonylethyl)-, or 3-exo-(2,2-diethoxycarbonylethyl)isocamphanone respectively. When the reaction with ethyl cyanoacetate and diethyl malonate is carried out in methanol occurs transalkylation of the ester groups resulting in the corresponding methyl esters, and in THF occurs hydrolysis to form carboxylic acids. In ethanol or methanol in the presence of equimolar or excess amounts of alkali compounds with cyano groups suffer cyclization into the corresponding 2-alkoxy-3-cyano- or 1-alkoxy-3-alkoxycarbonyl-7,7,8-trimethylbicyclo[2.2.1]hepteno[2.3-b]pyridines. In THF partially form analogous tricyclic 2-hydroxypyridines.     

Microwave Enhanced Knoevenagel Condensation of Malonic Acid on Basic Alumina

Abstract: An improved Knoevenagel condensation of malonic acid and aldehydes can be achieved by microwave irradiation over alumina. A number of diacids were prepared in good yields in very short reaction times.     

Changing Perspectives on the Strategic Use of Microwave Heating in Organic Synthesis

This Personal Account describes collaborative investigations into apocryphal microwave effects in organic chemistry. Focused research on microwave‐assisted organic synthesis has been fraught with confusion, controversy, and misinformation. Microwave heating is an undoubtedly useful tactic for organic synthesis, but whether or not it can offer strategic advantages remains an open question in the minds of many people. (Ironically, those who do not consider it an open question are split as to whether it has been resolved affirmatively or negatively.) Our research in this area is guided by the hypothesis that microwave heating can alter reaction kinetics in ways distinct from what is observable under conventional heating. Here we provide a succinct record of the origins of our interests, our initial queries and associated controversies, and recent efforts to identify, quantify, and begin to leverage selective microwave heating for strategic advantage in organic synthesis.     

Microwave Heating in Synthesis: Preparation of Allyldiphenylphosphine Oxide

A new one-pot synthesis of allyldiphenyl-phosphine oxide has been developed using a tandem Sn2′ / Michaelis-Arbuzov sequence. The application of microwave heating lowers the reaction time significantly.     

Selective Decarboxylation: A Facile Synthesis of 3-Pyridinecarboxylic Acid Derivative

A convenient synthesis of 5-trifluoromethyl-3-pyridinecarboxylic acid was developed, involving palladium-catalyzed carbonylation, hydrolysis, and decarboxylation. This novel route features inexpensive starting material and easy operations.     

Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives Catalyzed by p-Dodecylbenezenesulfonic Acid in Water

With the increasing concerns of the environment, more and more chemists are devoted to the research of the "green synthesis" which means that the reagent, solvent and catalyst are environmentally friendly in the organic chemical reactions. The importance of aqueous reaction is now generally recognized, and development of carbon-carbon bond-forming reactions that can be carried out in aqueous media is now one of the most challenging topics in organic synthesis.[1]Herein, we report a clean synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxo-octahydroxanthene derivatives from aromatic aldehyde and 5,5-dimethyl-1,3-cyclohexadione using p-dodecylbenezenesulfonic acid (DBSA) as the catalyst in water.This method provides several advantages such as high yield, simple work-up procedure and environmental friendliness and water was chosen as a green solvent. All the products were characterized by m.p., 1H NMR, IR and elemental analyses.     

Microwave Activation in Organic Synthesis

Data on the effect of microwave irradiation on organic reactions are reviewed. Possible mechanisms of microwave activation are discussed, and some examples of acceleration of organic reactions and change of their direction and selectivity as compared to traditional thermal activation are described. Specific aspects of the application of microwave activation to various fields of organic synthesis are considered. The review covers mainly the data published over the last 5 years.     

微波辐射下无催化剂一锅法合成N-甲基十氢吖啶-1,8-二酮化合物

为了研究从简单易得的原料在无催化剂的条件下一锅法合成N-甲基十氢吖啶-1,8-二酮化合物，我们以各类醛（脂肪醛、芳香醛、二醛）、达咪酮或1,3-环己二酮和甲胺为原料，以乙二醇或水为溶剂，经微波辐射，一步反应得到了一系列N-甲基十氢吖啶-1,8-二酮化合物。反应时间从传统热反应的4-5小时缩短至2-10分钟，产率较高（56-95%），并且不需要使用催化剂。该反应后处理方便，只需要简单洗涤，环境友好，为合成此类化合物提供了一种简便、有效的合成方法。该方法不仅适用于一元脂肪醛、芳香醛，还适用于芳香二醛，因此可以合成含有一个或两个十氢吖啶结构单元的杂环化合物。     

微波促进下2-芳氧甲基苯并咪唑-1-乙酸衍生物的合成及生物活性研究

采用微波辐射和相转移催化技术, 在K₂CO₃存在下利用PEG-400作相转移催化剂, 经过N-烷化、水解和酸化等步骤合成了10种尚未见文献报道的2-芳氧甲基苯并咪唑-1-乙酸衍生物. 经元素分析, FT-IR, ¹H NMR和¹³C NMR确证了其结构. 生物活性实验结果表明该系列化合物对小麦幼苗根系和芽的生长均有明显的调节活性.     

Microwave Assisted Synthesis of Pyridone Derivatives

A series of pyridone derivatives were synthesized by the reaction of aromatic aldehydes, 1,3‐dicarbonyl compounds and ammonium acetate under microwave irradiation in the absence of solvent. The reactions were completed within 3‐5 min to give the desired products in 72.4‐86.2% yields.     

Efficient One-Pot Synthesis of Polyhydroquinoline Derivatives Using Silica Sulfuric Acid as a Heterogeneous and Reusable Catalyst Under Conventional Heating and Energy-Saving Microwave Irradiation

An efficient Hantzsch four-component condensation reaction for the synthesis of polyhydroquinoline derivatives was reported under two conditions: solvent-free conventional heating and energy-saving microwave irradiation. The process is simple and environmentally benign, and the use of a heterogeneous and reusable catalyst, high yields, and short reaction times are the key features of this protocol.     

藤黄酸衍生物的合成

以具有抗癌活性的藤黄酸为原料,通过酯化和酰胺化反应修饰其30-CO2H,合成了8个藤黄酸衍生物,其结构经1H NMR,IR和MS确证。     

Synthesis of Cinnamic Acid Derivatives Using Ethanol as Solvent or Microwave Assisted Method.

A comparison study about some parameters which influence the condensation of veratraldehyde with malonic acid in the presence of piperidine using ethanol as solvent and microwave irradiation was done, the obtainment of several substituted cinnamic acids are reported.     

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.     

含吡啶基的L-酒石酸衍生物的合成

以L-酒石酸为原料,合成了一端是羧酸、另一端是吡啶基的手性配体(4R,5R)-2,2-二甲基-5-[(4-吡啶氨基)羰基]-1,3-二氧戊环-4-甲酸和两端都是吡啶基的手性配体(4R,5R)-2,2-二甲基-N,N'-(吡啶-4-基)-1,3-二氧戊环-4,5-二甲酰胺,其结构经1H NMR,IR和MS表征.     

甘草次酸衍生物的合成

以甘草次酸为原料,合成了4个甘草次酸衍生物.其结构经<'1>H NMR,IR和MS确证.     

Synthesis of Tetradecapentaenoic Acid Derivatives

Russian Journal of General Chemistry - A 12-stage method for the stereoselective synthesis of tetradecapentaenoic acid derivatives using phosphoric reagents was developed. The key step in the...