Synthesis Of Heterocyclic Systems Research Articles

ChemInform Abstract: Synthesis of Various Heterocyclic Compounds via Multi‐Component Reactions in Water

AbstractReview: 279 refs.

Synthesis of various heterocyclic compounds via multi-component reactions in water

Due to special effects of water such as abundant, environmentally benign, hydrogen bonding in the transition state and high cohesive energy density as well as negative activation volume; the use of water as a green solvent is emphasized in green chemical processes. Heterocyclic compounds play an important role in the treatment of many diseases and also are effective in biological processes. Multi-component reactions are powerful synthetic methods in construction of new organic molecules because in these methods product is formed as one-pot and reduced number of reaction separation steps. For these reasons, the synthesis of heterocyclic systems using a simple multi-component approach in water is investigated greatly in the recent years. In this review, multi-component reactions that have been used for the synthesis of heterocyclic compounds in aqueous media during the last two decades are described.

ChemInform Abstract: Enamino Esters in the Synthesis of Heterocyclic Systems. Transformation of Dimethyl Acetone‐1,3‐dicarboxylate into Polysubstituted 1,6‐Naphthyridine‐8‐carboxylates.

Abstract8 Title compounds of type (V) are prepared.

Enamino Esters in the Synthesis of Heterocyclic Systems. Transformation of Dimethyl Acetone-1,3-dicarboxylate into Polysubstituted 1,6-Naphthyridine-8-carboxylates

Enamino Esters in the Synthesis of Heterocyclic Systems. Transformation of Dimethyl Acetone-1,3-dicarboxylate into Polysubstituted 1,6-Naphthyridine-8-carboxylates

Enamino esters in the synthesis of heterocyclic systems. Transformation of diethyl acetone-1,3-dicarboxylate into poly-substituted 1,2,7,8-tetrahydro-2,7-naphthyridine-4-carboxylates

A simple three step synthesis of aminosubstituted 1,2,7,8-tetrahydro-2,7-naphthyridine-4- carboxylates is described. Ethyl (3-cyano-6-ethoxy-2-oxo-1,2-dihydropyridin-4-yl)acetate 3, formed by the condensation of diethyl acetone-1,3-dicarboxylate with malononitrile, was transformed with N,N-dimethylformamide dimethylacetal (DMFDMA) into (E)-ethyl 2-(3- cyano-6-ethoxy-2-oxo-1,2-dihydropyridin-4-yl)-3-(dimethylamino)propenoate 4. In further reaction the dimethylamino group was substituted with amino, hydroxy or substituted hydrazino group, followed by cyclisation to afford substituted 1-amino-7,8-dihydro-2,7-naphthyridine-4- carboxylate 6b, 1-imino-7,8-dihydro-1H-pyrano(3,4-c)pyridine-4-carboxylate 8, and 1-imino-2- aminosubstituted 1,2,7,8-tetrahydro-2,7-naphthyridine-4-carboxylates 13a-i.

ChemInform Abstract: Dialkyl Acetone‐1,3‐dicarboxylates and Their Mono‐ and Bis(dimethylamino)methylidene Derivatives in the Synthesis of Heterocyclic Systems

AbstractReview: about 100 refs.

ChemInform Abstract: Methyl 2-Benzoylamino-3-dimethylaminopropenoate in the Synthesis of Heterocyclic Systems. A Simple Synthesis of Amino Derivatives of Isomeric Naphthopyranones and Naphthodipyranones.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Amino Acids in the Synthesis of Heterocyclic Systems. A Novel Synthesis of Fused Pyridinones.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Utility of thiocarbohydrazide in heterocyclic synthesis

This review describes the synthesis and properties of thiocarbohydrazide and its utility as a building block for the synthesis of heterocyclic systems with pharmacological interest.

Synthesis of Heterocyclic Systems by Transition Metal Catalyzed Cyclization—Migration Reactions — A Diversity‐Oriented Strategy for the Construction of Spirocyclic 3(2H)‐Furanones and 3‐Pyrrolones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Synthesis of Heterocyclic Systems by Transition‐Metal‐Catalyzed Cyclization‐Migration Reactions – A Diversity‐Oriented Strategy for the Construction of Spirocyclic 3(2H)‐Furanones and 3‐Pyrrolones

AbstractTwo platinum(II)‐catalyzed heterocyclization‐migration reactions that provide five‐membered heterocycle products are described. With 5 mol‐% of PtCl2 as a catalyst, 2‐alkynyl‐2‐hydroxy carbonyl compounds 1 are converted into 3(2H)‐furanones 2 at 80 °C in moderate to excellent yields under very mild reaction conditions. The reaction is proposed to proceed through an oxonium ion intermediate B, which triggers a stereospecific 1,2‐shift analogous to an α‐ketol rearrangement. When exploited in a different manner, the 2‐alkynyl‐2‐hydroxy carbonyl compounds 1 afford 3‐pyrrolones 3 in 33–81 % yield. For this purpose, the starting compounds 1 are treated with primary amines in the presence of 5 mol‐% of PtCl2 at 100 °C in a convenient one‐pot process. These cyclization‐migration reactions give novel access to 3(2H)‐furanones and 3‐pyrrolones in which the 2‐position bears aryl or alkyl substituents. Synthetically challenging spirocyclic compounds can be prepared in this fashion by ring contraction. Studies that define the scope and limitations of the cyclization‐migration synthesis of heterocyclic systems are also described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The synthesis of functionalised chiral bicyclic lactam and lactone N-oxides using a tandem Cope elimination/reverse Cope elimination protocol

Functionalised hydroxylamine derivatives of ( S)-proline and ( R)-pipecolic acid have been prepared using a Cope elimination. These undergo reverse Cope elimination onto a pendant double bond to give bicyclic lactam and lactone N-oxides containing three contiguous chiral centres, this extends the scope and applicability of the reverse Cope elimination in the synthesis of heterocyclic systems by incorporation of the lactone and lactam structural motifs.

Heterocyclic Chemistry of Sulfur Chlorides — Fast Ways to Complex Heterocycles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Application of Gold Catalysis in the Synthesis of Heterocyclic Systems

AbstractFor Abstract see ChemInform Abstract in Full Text.

The Use of 4‐(Bromomethylene)‐5,5‐dimethyl‐1,3‐dioxolan‐2‐one as “Masked” α‐Bromo‐α′‐hydroxy Ketone in the Synthesis of Heterocyclic Systems.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Oxalic Acid: A Very Useful Brønsted Acid in Organic Synthesis

The title compound oxalic acid is available in anhydrous and dihydrate forms and exhibits several features which have made it particularly attractive as a reagent in organic synthesis. Oxalic acid is a mild Brønsted acid, which finds application in the Beckmann reaction, [1] protection and deprotection of carbonyl compounds, [2-4] and various selective cleavage and hydrolytic reactions. It is frequently used as a mild acidic quench for a variety of reactions including oxidations. [5] Oxalic acid has also been used as an acidic agent in a number of condensation processes such as conden­sation of allylic alcohols with aromatic rings, [6] carbonyl compounds and hydrazines, [7] aromatic amines and aldehydes, [8] and it has been utilized as a bifunctional condensation partner in the synthesis of heterocyclic systems. [9]

The Use of 4-(Bromomethylene)-5,5-dimethyl-1,3-dioxolan-2-one as “Masked” -Bromo- '-Hydroxy Ketone in the Synthesis of Heterocyclic Systems

4-(Bromomethylene)-5,5-dimethyl-1,3-dioxolan-2-one was obtained on the basis of the readily obtainable 4-methylene-5,5-dimethyl-1,3-dioxolan-2-one. It forms 2-imidazo[1,2-a]pyridin-2-yl-2-propanol with 2-aminopyridine, 11a-hydroxy-1,1-dimethyl-3-oxo-1,5,11,11a-tetrahydro[1,3]oxazolo[3,4-a]pyrido[1,2-d]-10-pyrazinium bromide with 2-(aminomethyl)pyridine, and the corresponding derivative of 4-hydroxyoxazolidin-2-one with 2-(3,4-dimethoxyphenyl)ethylamine. The last product was converted by intramolecular amidoalkylation without isolation into 10b-(bromomethyl)-8,9-dimethoxy-1,1-dimethyl-1,5,6,10b-tetrahydro[1,3]oxazolo[3,4-a]isoquinolin-3-one.

Novel Solution‐ and Solid‐Phase Syntheses of Heterocyclic Systems

AbstractFor Abstract see ChemInform Abstract in Full Text.

Simple One‐Step Syntheses of Heterocyclic Systems from (4Z)‐2‐Phenyl‐4‐(thien‐2‐ylmethylene)‐1,3(4H)‐oxazol‐5‐one.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Heterocyclic Systems by the Reaction of Zwitterionic Compounds with Isocyanates and Thiophosgene.

AbstractFor Abstract see ChemInform Abstract in Full Text.