Aqueous Synthesis of N-Phenyl/alkyl-2-quinolinone-3-carboxylic Acids from Coumarin-3-carboxylic Acids

An efficient, ecofriendly aqueous synthesis of aromatic/aliphatic amines with coumarin-3-carboxylic acid in a one pot reaction in a sealed tube or InCl₃/ H₂O in open vessel to afford N-phenyl/alkyl-2-quinolinones is achieved. This method provides high yield of products in shorter time, making it a useful process for the synthesis of structurally diversified 2-quinolinones from corresponding coumarins.     

Practical synthesis of a functionalized 1-oxo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid

The synthesis of a functionalized 1-oxo-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid has been performed in 10 steps from the readily available dimedone. Only three purifications by flash chromatography are required through the whole sequence. The key step is the reaction between a dimedone derivative and a chlorotetrolic ester, that gives a tetrasubstituted benzene ring (through a Diels-Alder/retro- Diels-Alder process) bearing the substituents in the suitable positions for further functionalization.     

5-卤代-1H-1,2,4-三氮唑-3-羧酸乙酯及其衍生物的合成

以5-氨基-1H1,2,4-三氮唑-3-羧酸乙酯为原料,经Sandmeyer反应合成了5-X-1H-1,2,4-三氮唑-3-羧酸乙酯(X=C1,Br,I)(1a-1c),1a-1c再分别与α-2′,4′-二氟苯乙酮反应合成了3个5-卤代-1-1H-1,2,4-三氮唑-3-羧酸乙酯衍生物(2a-2c),其结构通过元素分析,IR,UV和^1H NMR进行了表征。     

Silica Sulfuric Acid: A Versatile and Reusable Catalyst for Synthesis of Coumarin-3-carboxylic Acids in a Solventless System

Synthesis of substituted coumarin-3-carboxylic acid via Knoevenagel condensation of meldrum's acid with ortho-hydroxyaryl aldehydes in solventless system is described.     

The One-Pot Synthesis and Diels-Alder Reactivity of 2,5-Dihydrothiophene- 1,1-dioxide-3-carboxylic Acid

Abstract

A one-pot preparation of 2,5-dihydrothiophene-1,1-dioxide-3-carboxylic acid (3-sulfolene-3-carboxylic acid) is reported. The carboxylation of 3-sulfolene, exclusively at the 3-position, using CO₂ and DBU proceeds to >90% conversion. A rapid workup gives 3-sulfolene-3-carboxylic acid, a stable precursor to 1,3-butadiene-2-carboxylic acid. High conversions to Diels-Alder adducts were obtained upon treatment of 3-sulfolene-3-carboxylic acid with various dienophiles.     

Choline Chloride/Urea Ionic Liquid Catalyzed a Convenient One-Pot Synthesis of Indole-3-propanamide Derivatives

A sequential three-component reaction of aromatic aldehydes with Meldrum's acid and N-methyl indole in the presence of choline chloride/urea ionic liquid as green catalyst has been described. In this one-pot multicomponent reaction, a series of indole-3-propanamide derivatives were synthesized with good to excellent yields. This methodology shows several advantages including fast reaction, easy isolation, operational simplicity that make it a useful and attractive option for the library generation of indole-3-propanamides (5a–l) for drug discovery.

[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.]     

A Practical Synthesis of 1—Oxo—1,2,3,4—tetrahydroisoquinoline—3—carboxylic Acid Esters

A practical synthetic method for methyl 1-oxo-1,2,3,4-tetrahy-droisoquinoline3-3carboxylate was developed by menas of triphosgene,Several analogues were prepared by this new method.     

Rapid Synthesis of Novel and Known Coumarin‐3‐carboxylic Acids Using Stannous Chloride Dihydrate under Solvent‐Free Conditions

Various coumarin‐3‐carboxylic acid (=2‐oxo‐2H‐1‐benzopyran‐3‐carboxylic acid; CcaH) derivatives have been synthesized in good yields using catalytic amounts of SnCl₂?2 H₂O under solvent‐free conditions. This inexpensive, nontoxic, and readily available catalytic system (10 mol‐%) efficiently catalyzes the Knoevenagel condensation and intramolecular cyclization of various 2‐hydroxybenzaldehydes or acetophenones with Meldrum's acid. High product yields, use of inexpensive and safe catalyst, and solvent‐free conditions display both economic and environmental advantages.     

双Schiff碱的合成与表征

以5－氨基－1H－1，2，4－三氮唑－3－羧酸分别与对苯二甲醛，乙二醛和戊二醛反应合成了3个新的双Schiff碱化合物，结构经元素分析，IR，UV和1H NMR表征。     

Synthesis and characterization of Boc-protected 4-amino- and 5-amino-pyrrole-2-carboxylic acid methyl esters

Syntheses of Boc-protected 4-amino- and 5-amino-pyrrole-2-carboxylic acid methyl esters have been achieved and the structures of these compounds have been fully characterized by detailed NMR studies.     

Reaction of Barbituric, 2-Thiobarbituric Acids and Their Derivatives with 2-Carboxybenzaldehyde and Opianic Acid: Synthesis and Tautomerism of 5-(3'-Oxo-1',3'-dihydroisobenzofuran-1'-yl)barbituric Acids and Their 2-Thio Analogs

The reaction of barbituric, N-alkylbarbituric acids, and their 2-thio analogs with carboxybenzaldehyde and 2-carboxy-3,4-dimethoxybenzaldehyde leads to the formation of the corresponding 5-(3'-oxo-1',3'-dihydroisobenzofuran-1'-yl)barbituric and 2-thiobarbituric acids, the structures of which were studied by ¹H and ¹³C NMR spectroscopy and mass spectrometry. In DMSO the derivatives of barbituric acid exist in the form of mixtures of the ketone and enol tautomers, while their 2-thio analogs exist in the enol form. In chloroform the tautomeric equilibrium is displaced fully toward the ketone form.     

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

1 INTRODUCTION Chiral amino acids and their versatile derivatives are very useful compounds in many fields[1]. In com- parison with well-documented chiral α and β amino acids and amino alcohols, the studies of chiral γ, δ… ω amino acids and amino alcohols deserve more attention. For example, there have been numerous reports on versatile functions of γ aminobutyric acid (GABA) produced from L-glutamic acid in the presence of L-glutamate decarboxylase (GAD)[2]. However, the stereo…     

1H-吲唑-3-羧酸的合成

综述了1H-吲唑-3-羧酸的合成方法,并评述了其优缺点;同时介绍了作者在寻找其新合成方法中的一些探索。参考文献28篇。     

取代吲哚-3-甲酸类化合物的合成

吲哚-3-甲酸是一种重要的有机中间体,被广泛应用于医药与农药的合成.以取代邻硝基甲苯为原料,与N,N-二甲基甲酰胺二甲基缩醛(DMFDMA)反应制得取代2-硝基-β-二甲氨基苯乙烯,再经铁粉和冰乙酸还原环合生成取代吲哚,取代吲哚与三氟乙酸酐经酰化、碱性条件下水解制得5种取代吲哚-3-甲酸类化合物,该合成方法操作简单,条件温和,收率较高.     

Uncatalyzed solventless Diels-Alder reaction of 2-amino-3-nitroacrylate: synthesis of new epimeric 2-amino-3-nitro-norbornene- and norbornane-2-carboxylic acids

A highly diastereoselective Diels-Alder reaction between cyclopentadiene and ethyl (Z)-2-N-Boc-amino-3-nitroacrylate in neat conditions affords the ethyl 2-t-butoxycarbonylamino-3-endo-nitro-bicyclo[2.2.1]hept-5-ene-2-exo-carboxylate: a new constrained carbocyclic amino acid. Catalytic hydrogenation of this cycloadduct gave the corresponding reduced norbornane derivative. A preliminary investigation into the chemistry of these two amino acids was performed. In particular, the epimerization to their corresponding 3-exo-nitro compounds by treatment both with acid and base was studied. From this study, valuable information on the endo/exo process at the C-3 carbon atom, as well as on the stability of the different stereomers, was obtained. The stability is closely related to the presence or the absence of the double bond in the ring and to the substitution pattern. Finally, deprotection of the amino acid function has been performed.     

4-Hydroxyquinol-2-ones. 87. Unusual Synthesis of 1-R-4-Hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic Acid Pyridylamides

4-Chloro-2-oxo-1,2-dihydroquinoline-3-carboxylic acids and their esters react with aminopyridines in refluxing DMF to give the corresponding 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid pyridylamides. Their structures were proved by ¹H NMR and mass spectroscopy, counter synthesis, and by X-ray analysis. A possible mechanism is proposed for the indicated chemical reaction. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1362–1371, September, 2005.     

Facile and efficient synthesis of quinoline-4-carboxylic acids under microwave irradiation

<正>A facile and efficient method for the preparation of 2-non-substituted quinoline-4-carboxylic acids is described via the Pfitzinger reaction of isatins with sodium pyruvate following consequent decarboxylation under microwave irradiation.     

Silver-catalyzed facile decarboxylation of coumarin-3-carboxylic acids

A simple and highly efficient protocol with mild reaction conditions has been developed that allows the smooth protiodecarboxylation of diversely functionalized coumarin-3-carboxylic acids. In the presence of catalytic amounts of Ag₂CO₃ and acetic acid, even un-activated coumarin-3-carboxylic acids were converted in good to excellent yields and with great preparative ease to the corresponding coumarin derivatives.     

Synthesis and anticancer properties of 7α-chloro-3-methyl-1,1-dioxoceph-3-em-4-carboxylic acid esters

The tert-butyl esters of 3-azidomethyl-, 3-isocyanatomethyl-, 3-chloromethyl-, and 3-p-nitrophenylvinyl-7α-chloro-1,1-dioxoceph-3-em-4-carboxylic acid, and also esters of 7α-chloro-3-methyl-1,1-dioxoceph-3-em-4-carboxylic acid, and of 7α-chloro-3-methyl-2-dimethylaminomethylene-1,1-dioxoceph-3-em-4-carboxylic acid have been synthesized. Results of cytotoxic screening of these compounds in relation to cancer and normal cells in vitro are correlated and analyzed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 259–273, February, 2007.     

4-hydroxy-2-quinolones. 153*. Synthesis of hetarylamides of 4-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylic acid

4-Methyl-2-oxo-1,2-dihydroquinoline-3-carboxylic acid hetarylamides can be prepared by two fundamentally different routes with allowance made for the thermal stability of the starting hetarylamines. * For Communication 152 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 426–432, March, 2009.