Methoden zur Darstellung von 4-Azido-2(1H)-chinolonen

4-Hydroxy-2-quinolones1 are generally found to be converted to the 4-azidocompounds3 via the 4-chloroquinolones2, the 4-tosyloxyquinolones6, or the 4-aminoquinolones4, respectively. Choice of the reaction conditions and yields depend on the substituent in position 3 of the quinoline nucleus. For comparison the O-analogous coumarin derivatives9 have been studied to give the 4-azidoderivatives11 via the 4-chlorocoumarins10.

     

Zur Reaktion von 4-Alkylaminodihydro-2(1H)-pyridinthionen bzw. -onen mit Ethylmalonsäure-bis-trichlorphenylester

4-Alkylamino-2(1H)-pyridinethiones (1) react with bis-trichlorphenylethylmalonate (3) to give four isomeric products: 5-thioxo-1,6-naphthyridine-2(1H)-ones (4), 7,7-dimethyl-4H-thiopyrano[2,3-b]pyridine-4-ones (6), 2,2-dimethyl-2H-thiopyrano[2,3-b]pyridine-5,7-dioles (7) and 2,2-dimethyl-2H-thiopyrano[2,3-b]pyridine-5(3H)-ones (8). On treatment with alkali the thioxogroup of4 is hydrolyzed and 1,6-naphthyridinediones (5) are formed. Compound5 can also be synthesized by heating the alkylaminopyridones (2) together with3.6 can be hydrolyzed to 2-thioxo-3-pyridylpropylketones (12). On treatment with diluted alkali or conc. acid the aminogroup of7 and8 is hydrolyzed and10 is formed. By heating in 20% NaOH10 is transformed to the dihydroxymercapto-3-pyridylmethylketone (11).

Herrn Prof. Dr.Erich Ziegler mit den besten Wünschen zum 70. Geburtstag gewidmet.     

Facile Iodine(III)-Mediated Approach for the Regioselective Chlorination of 2-Aryl-2,3-dihydro-4(1H)-quinolones

Oxidation of 2-aryl-2,3-dihydro-4(1H)-quinolones (1) with 1.5 equivalents of (dichloroiodo)benzene in dichloromethane at room temperature leads to regioselective chlorination, thereby offering an efficient method for the synthesis of new 2-aryl-6-chloro-2,3-dihydro-4(1H)-quinolones (3).     

Preparation of Resin-Bound Bismethylene Cyclic Malonic Acid Ester and Facile Solid-Phase Synthesis of 2-Alkylthio-4(1H)-quinolone and 2-Alkyl-4(1H)-quinolone

Abstract

The resin-bound bismethylthiomethylene cyclic malonic acid ester 3 was built up efficiently. Resin 3 can react with arylamines and subsequent thermal cyclizations give 2-alkylthio-4-(1H)-quinolones. Furthermore, conjugate addition of Grignard reagents to the resin 3 forms the resin 6 which was reacted with aryl amines and subsequent thermal-cyclization-cleavages afford the 2-alkyl-4-(1H)-quinolones.     

Eine einfache Synthese von 11H-Indolo[3,2-c]chinolin-6-onen

11H-Indolo[3,2-c]quinolin-6-ones, which are containing the -carboline ring system, can be easily synthesized from 4-azido-3-phenyl-2(1H)-quinolones, which are obtained in a two step reaction from 4-hydroxy-3-phenyl-2(1H)-quinolones. Cyclization of the azides can be realized by irradiation or thermal reaction.

     

Zur Ringumwandlung von 2-Amino-thiophen-3-carbonsäureestern: Pyridon- und Pyridazinon-Derivate

Whereas treatment of the ethyl 5-acetyl-2-amino-4-methyl-thiophene-3-carboxylate (1) with potassium hydroxide yields the 2-hydroxy-thiophene-3-carbonitrile4 its hydrazone2 is converted into the 1-amino-5-mercapto-2-pyridone derivative6. The transformation of the 2-amino-5-phenylazo-thiophene derivative9 by potassium hydroxide yields the substituted 3-mercapto-pyridazin-6(1H)one10, with sodium ethoxide the 5-phenylhydrazono-2-oxo-thiolen-3-carbonitrile11 is formed. From6 the 5-mercapto-2-pyridone derivatives7 d,e can be obtained.

     

A facile synthesis of 4-aryl-2H-1-benzopyran-2-ones

Reaction of 2-hydroxybenzophenones (1,3,7,8) with ethoxycarbonyl-methylenetriphenylphosphorane affords 4-aryl-2H-1-benzopyran-2-ones (2,4–6) in excellent yields.

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Eine einfache Synthese für 4-Aryl-2H-1-benzopyran-2-one

Zusammenfassung Die Reaktion der 2-Hydroxybenzophenone1,3,7 und8 mit Ethoxycarbonyl-methylentriphenylphosphoran ergab die 4-Aryl-2H-1-benzopyran-2-one2 und4–6 in ausgezeichneten Ausbeuten.

     

Synthese von 3,3a-Dihydro-2H,5H-azeto[2,1-b]benzo[d]1,3-oxazin-2,5-dionen, 2. Mitt.

Starting from the thioformimidates4 a, b, c and substituted acetylchlorides, the 3R*/4S* 4-methylthio-2-azetidinones5, 13 a, b, c are synthesized.5 is dehalogenated to6. Debenzylation of6 leads to7 and10, which undergo ring closure to9 and12 by the action of chlorine inDME. Hydrazinolysis of13 a, b, c and acylation of the intermediates14 a, b, c afford15 a, b, c. Removal of the protective groups leads to16 d, e, f. The diastereomeric mixtures17 d, e, f, which are obtained by the chlorolysis of16 d, e, f, undergo ring closure to the 3R*/4S* isomers of the title compounds18 d, e, f either spontaneously or by action of silvertetrafluoroborate/silveroxide. Chlorolysis of19 yields the diastereomeric mixture20. Treatment of20 with silvertetrafluoroborate/silveroxide gives21 and22.

Herrn Professor Dr.Hermann Bretschneider zum 80. Geburtstag gewidmet.     

Saturated heterocycles, 68. Application of theSeth-Paul-Van Duyse equation,IX

The C=O stretching frequencies of 32 5,6-polymethylenepyrimidin-4(3H)-one (1a–1w) andcis-5,6-polymethylene-5,6-dihydropyrimidin-4(3H)-one (2a–2h) derivatives were measured in tetrachlormethane and in chloroform and correlated with the substituent constantsX ⁺ (R) in the sense of the modified and extendedSeth-Paul-Van Duyse equation. It was found that the C=O stretching frequency and the transmission of substituent effects through the heterocyclic ring are significantly influenced by the size of the fused hydrocarbon ring. Evidence was obtained that in molecules linked by intermolecular hydrogen bonds the substituent effects are transmitted to the C=O group predominantly via the C=N–C=C part of the pyrimidinone ring. In the free molecules the transmission of substituent effects takes place mainly through the NH group.

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Gesättigte Heterocyclen, 68. Mitt.: Anwendung der Seth-Paul-Van Duyse-Gleichung, IX. Die C=O-Streck-Frequenzen und Substituenteneffekte bei 5,6-Polymethylenpyrimidin-4(3H)-on Derivaten

Zusammenfassung Es wurden die C=O-Streck-Frequenzen von 32 5,6-Polymethylenpyrimidin-4(3H)-onen (1a–1w) undcis-5,6-polymethylen-5,6-dihydropyrimidin-4(3H)-onen (2a–2h) in CCl₄ und CHCl₃ gemessen und mit den SubstituentenkonstantenX ⁺ (R) im Sinn der modifizierten und erweitertenSeth-Paul-Van Duyse-Gleichung korreliert. Es wurde festgestellt, daß die C=O-Streck-Frequenzen und die Übertragung von Substituenteneffekten durch den heterocyclischen Ring von der Größe des kondensierten Kohlenwasserstoffringes signifikant beeinflußt werden. Es konnte belegt werden, daß in Molekülen, die mit Wasserstoffbrücken verbunden sind, die Substituenteneffekte vorwiegend über den C=N–C=C-Teil des Pyrimidinonringes zur C=O-Gruppe übertragen werden. In den freien Molekülen erfolgt die Übertragung der Substituenteneffekte hauptsächlich über die NH-Gruppe.

     

A short synthesis of 2,3,4-trihydrodibenzofuranes

Summary Treatment of 2-phenoxypropionic acid with polyphosphoric acid gave substituted benzofuran-3-ones (2a–h), which were converted into 2,3,4-trihydrodibenzofuran-3-ones (4a–h)via the compounds3a–h.Clemmensen reduction of the compounds4a–h gave the 2,3,4-trihydrodibenzofuranes (5a–h).

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Eine einfache Synthese von 2,3,4-Trihydrobenzofuranen

Zusammenfassung Behandlung von 2-Phenoxypropionsäure mit Polyphosphorsäure lieferte die substituierten Benzofuran-3-one (2a–h), welche über3a–h in die 2,3,4-Trihydrodibenzofuran-3-one (4a–h) übergeführt wurden. DurchClemmensen-Reduktion von4a–h wurden die gewünschten 2,3,4-Trihydrobenzofurane (5a–h) erhalten.

     

The green synthesis of 2,3-dihydroquinazolin-4(1H)-ones via direct cyclocondensation reaction under catalyst-free conditions

ABSTRACT

A simple and environmentally benign method is described for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by direct cyclocondensation of 2-aminobenzamide with aromatic aldehydes using water as the reaction medium. The parameters such as temperature, substrate molar ratio and reaction time were examined to establish the optimal synthetic process. The present procedure has advantages of low cost, mild reaction conditions, simple workup process, simply purification, excellent yields and no use of catalyst and hazardous organic solvents.     

Facile synthesis and characterization of novel pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one and pyrido[2′,3′:3,4]pyrazolo[1,5-a]pyrimidine incorporating 1,3-diarylpyrazole moiety

4-(3-(4-Hydroxyphenyl)-1-phenyl-1H-pyrazol-4-yl)-6-phenyl-2-thioxo-1,2-di hydro-pyridine-3-carbonitrile (1) reacted with ethyl chloroacetate (2) in ethanolic sodium acetate solution to yield the corresponding ethyl (3-cyanopyridin-2-ylsulphanyl)acetate derivative 3. Intramolecular cyclization of compound 3 was achieved by its heating in DMF containing potassium carbonate to afford the corresponding ethyl 3-aminothieno[2,3-b]pyridine-2-carboxylate derivative 4 which reacted with hydrazine hydrate in refluxing pyridine to yield the starting material 3-aminothieno[2,3-b]pyridine-2-carbohydrazide derivative 7. Compound 7 reacted with different reagents such as triethylorthoformate, formic acid, acetic acid and acetic anhydride to afford the target molecules pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidin-4(3H)-one derivatives 8–10, 12 and 13 in good to excellent yields. On the other hand, pyridine-2(1H)-thione derivative 1 reacted with hydrazine hydrate in refluxing pyridine to give the other starting material 3-amino-1H-pyrazolo[3,4-b]pyridine derivative 20 which reacted with acetylacetone under reflux to afford the target molecule pyrido[2′,3′:3,4]pyrazolo[1,5-a]-pyrimidine derivative 21 in a good yield. The structures of target molecules were elucidated using elemental analyses and spectral data.     

Molecular Iodine as a Versatile Reagent for the Synthesis of Thiazoloquinoline—A Potential Antibacterial Agent

Abstract

A series of 3-(2-aminothiazol-4-yl)quinolin-2[1H]-ones 3 was prepared by neat reaction of quinolin-2[1H]-ones 1 with thioureas 2 in the presence of molecular iodine. The synthesized compounds were evaluated for their in vitro antimicrobial activities against Escherichia coli, Paedococcus sp., Lactobacillus, Yersinia enterocolitica, and Staphylococcus aureus. The green chemical approach for the synthesis of thiazoloquinolinone 3 was performed under neat conditions using molecular iodine as catalyst as well as reaction medium.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT      

Zur Chemie der Thioladdition an 2,3-Dihydro-3-ethylidendipyrrin-1(10H)-one—eine Modellstudie zur kovalenten Chromophor-Protein-Bindung in Biliproteiden

Addition of benzylmercaptan to 2,3-dihydro-3-ethylidenedipyrrin-1(10H)-one (Z,Z)-3 was found to be a model reaction with regard to the thioether linkage of protein and chromophore in biliproteins. Isolation and characterization of the main product4 reveals the ethylidene double bond to be attacked first by thiol according to the principles of the acid catalysed nucleophilic addition.

     

Über N1- und N2-substituierte 2-Amino-5,6-dihydro-4(1H)-pyrimidinone

The reactions of the monosubstituted guanidines2 b-h with methyl acrylate in dimethylformamide or ethanol as solvent preferentially afford 1-substituted 2-amino-5,6-dihydro-4(1H)-pyrimidinones6 b-h. The structures of 1-hexyl- and 1-benzyl-4-pyrimidinones6 c, e and of the picrate of 1-phenylpyrimidinone6 g were proved by comparison with authentic samples, which were prepared from N-substituted ethyl 3-amino-propionates14 c, e andg and cyanamide. Accordingly,6 g is not identical with authentic 2-phenylaminopyrimidinone7 g (prepared from 2-methylthio-4-pyrimidinone10 and 2-thioxo-4-pyrimidinone12 respectively, compare¹⁰).N,N-Disubstituted guanidines2 i-m react with methyl acrylate in dimethylformamide as solvent to afford N²,N²-disubstituted 2-amino-5,6-dihydro-4-(1H)-pyrimidinones7 i-m. Action of morpholine-4-carboxamidine (21) on methyl acrylate in ethanol yields 2-morpholinopyrimidinone71 as byproduct and 3-ethoxy-N-[morpholino(amino)methylene]propionamide (91) as mainproduct.

Herrn Prof. Dr.Robert Ott mit den besten Wünschen zum 60. Geburtstag gewidmet.     

Synthesis of 4-hydroxy-2(1H)-pyridones from azomethines and substituted dialkylmalonates

Summary The reaction of azomethines4 with substituted dialkyl malonates5 leads to the formation of 3-substituted 4-hydroxy-2(1H)-pyridones6 in moderate yields. The azomethines4 are preparedvia arylaminopropionitriles3 or in the conventional way by acid catalyzed condensation of ketones1 with anilines2. Chlorination of pyridones6 with sulfuryl chloride leads to compounds8–10.

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Synthese von 4-Hydroxy-2(1H)-pyridonen aus Azomethinen und substituierten Dialkylmalonaten

Zusammenfassung Umsetzung der Azomethine4 mit den substituierten Dialkylmalonaten5 ergibt die in 3-Stellung substituierten 4-Hydroxy-2(1H)-pyridone6 in mäßigen Ausbeuten. Die Azomethine4 werden entweder über dieStrecker-Verbindungen3 oder konventionell über durch Säuren katalysierte Kondensation der Ketone1 mit den Aminen2 hergestellt. Chlorierung der Pyridone6 mit Sulfurylchlorid führt zu den Verbindungen8–10.

     

Reactions with pyrrolidine-2,4-diones,II: New approaches to the synthesis of substituted 5,6-dihydropyrrolo[3,4-d][1,2,3]triazol-4(2H,4H)ones

Summary Approaches leading to 5,6-dihydro-5,6-diphenyl-2-substituted-pyrrolo[3,4-d][1,2,3]-triazol-4(2H,4H)-ones (10) are described. The first approach consists of cyclodehydrating 3(or 4)-hydroxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (4,7) with boiling acetic anhydride. The second approach involves cyclization of 3(or 4)-acetoxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (8,9) with elimination of acetic acid upon treatment with sodium hydroxide.Part of the work has been presented at the 8^th International Congress of Heterocyclic Chemistry (August 1981), Graz, Austria     

Pictet-Spengler reactions of Tryptamine and tryptophan with cycloalkanones and ketonicMannich bases

APictet-Spengler reaction of Tryptamine (1) with cyclopentanone under physiological conditions gave 3-(cyclopentylideneaminoethyl)indole (3), which was cyclized to the 1-spirocyclic 1,2,3,4-tetrahydro-2-carboline (4). Treatment of (±)-tryptophan with cyclopentanone and cyclohexanone in acidic medium afforded the spirocyclic systems5 and6, respectively. ThePictet-Spengler reaction was extended further using ketonic bis-Mannich bases, to give compounds7 and8. The possibility of using other types of ketonic bases was investigated.

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DiePictet-Spengler-Reaktion von Tryptamin and Tryptophan mit Cycloalkanonen und Keto-Mannich-Basen

Zusammenfassung DiePictet-Spengler-Reaktion von Tryptamin (1) mit Cyclopentanonen ergab unter physiologischen Bedingungen 30(Cyclopentylidenaminoethyl)indole (3), die zu den spirocyclischen Tetrahydro-2-carbolinen4 cyclisiert wurden. Die Behandlung von (±)-Tryptophan mit Cyclopentanon oder Cyclohexanon in saurem Milieu ergab die spirocyclischen Systeme5 oder6. DiePictet-Spengler-Reaktion wurde auch auf Keto-Bis-Mannich-Basen zur Synthese der Verbindungstypen7 und8 ausgeweitet. Die Möglichkeiten zur Nutzung anderer Keto-Basen wurde untersucht.

     

Synthese von chinolin-kondensierten 2-Chinolonen und Cumarinen via Azidoverbindungen

Coumarins and 2-quinolones (1), having a 4-azido-3-benzyl-moiety, can easily by cyclized by thermo- or photolysis to 3,4-fused quino-coumarins and quino-2-quinolones (2,3).

     

Synthese von 3,3a-Dihydro-2H,5H-azeto[2,1-b]benzo[d]-1,3-oxazin-2,5-dionen,I

The thioformimidates4, which may be obtained by S-alkylation of the thioformamides3, react with chloroacetylchloride/triethylamine to yield the (3R, 4S/3S, 4R)-3-chloro-4-methylthio-2-azetidinones5. Dehalogenation of5 leads to6, which undergoes ring closure by the action of mercuric oxide. Treatment of8, which may be synthesized by chlorolysis of7, with triethylamine gives also the title compounds9.