Ylide von Heterocyclen,VIII Reaktionen von Iodonium-Yliden mit Säuren

The reaction of various organic and inorganic acids (HX) with iodonium ylides2 leads to nucleophilic substitution of the iodobenzene substituent by the anionX ^– to yield the heterocycles5. Some of them are hydrolyzed to the hydroxy compounds3 or reduced to the starting compounds1 under the reaction conditions. Reaction of the iodonium ylide2b with monomethyl sulfate gives the salt9, which with bases undergoes nucleophilic substitution to compounds8 and10–12, respectively, or is converted to2b again.

     

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).     

Isochinolino[4,3-c]chinolone aus Phenylmalonylheterocyclen

The reaction of 3-Phenyl-4-hydroxy-2-quinolones (1) and benzylammonium chloride yields the 4-aminocompounds2 as main products. The isoquinocondensed quinolones3 are formed as by-products. Thermolysis of 4-benzylamino-2-quinolones (4) affords also3. Better yields of3 are obtained by condensing the 4-aminoquinolones2 with benzaldehyde followed by thermal cyclodehydrogenation of the benzylidenamino compound6.

Hern Prof. Dr.E. Ziegler zur Vollendung seines 70. Lebensjahres gewidmet.     

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.     

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.

     

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.     

On theMichael type addition of dipeptides to 4-oxo-4-phenyl-2-butenoic acid derivatives

The title reaction afforded the adducts3 in variable selectivity, but the isomers of (S,S,S)-configuration were easily isolated; the reversibility of the reaction permits the recovery of the starting materials from the mother liquor. High selectivity has been observed in one case only.

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ZurMichael-ähnlichen Addition von Dipeptiden an Derivate der 4-Oxo-4-phenyl-2-butensäure (Kurze Mitteilung)

Zusammenfassung Die Titelreaktion liefert die Addukte3 in unterschiedlicher Selektivität; die Isomeren mit (S,S,S)-Konfiguration konnten jedoch einfach isoliert werden, und die Reversibilität der Reaktion ermöglicht die Rückgewinnung der Ausgangsstoffe. Eine hohe Selektivität wurde nur in einem Fall beobachtet.

     

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.     

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.

     

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.

     

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      

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).

     

A new naphthalenone isolated from the green walnut husks of Juglans mandshurica Maxim.

Phytochemical study of green walnut husks of Juglans mandshurica Maxim. led to the isolation of a new naphthalenone, (4R)-3,4-dihydro-4-butoxy-5-hydroxy-naphthalen-1(2H)-one (1), together with 16 known compounds. Compounds 4–6, 13, 14 and 17 were isolated from the genus Juglans for the first time, and their chemotaxonomic significance was also evaluated.     

Zur Synthese des 6,7-Dihydro-15-hydroxy-7,7-dimethylbenzo[2,3] (1,6)-naphthyridino[5,6-b]chinazolin-9-ons

The reaction of1,1-dimethyl-3-oxobutylisothiocyanate1 with methyl anthranilate takes place via the 2-(2-thioxopyrimidine-1)-benzoic methylester2 a, which is rearranged to the methyl thioxopyridineanthranilate3 a. 3 a is alkylated by methyl anthranilate to the corresponding methylthio-product4 a, which reacts with anthranilic acid via5a to the benzo [1,6]naphthyridino[5,6-b]-chinazoline6. 6 can also be synthesized by condensation of 2-methylthiopyridines9 a, b with anthranilic acid and 4-dimethylaminpyridine-2-thione8a with methyl anthranilate resp.

     

Über Reaktionen von Alkylbiguaniden mit Benzoin beimpH der Biguanidbasen

Summary Alkylbiguanides2 a–e react with benzoin (1) at thepH of the base in different ways.1 undergoes in presence of2 a, c oxidation to benzoic acid which reacts with the bases2 a, c to yield 4-phenyl-1,3,5-triazinamines3 c, 4 c; in presence of2 b 1 is transformed to benzil, which reacts with2 b under rearrangement to yield 1-(4-oxo-5,5-diphenyl-2-imidazolin-2-yl)-3,3-dimethylguanidine (5 b). However, the cycloalkylbiguanides2 d, e, react in presence of nitrogen as well as oxygen with1 to yield piperidine-1-[N-(4,5-diphenylimidazol-2-yl)-carboxamidine] (7 d), resp. morpholine-4-[N-(4,5-diphenylimidazol-2-yl)-carboxamidine] (7 e). The structure of7 e was established by means of an X-ray structure analysis. All proton- and carbon resonances were assigned on the basis of 2-dimensional NMR data.

     

Über die Struktur der Acrylnitril-Guanidin-Kondensate Über Heterocyclen, 78. Mitt.

Repetition of the work ofSugino andTamaka ¹ showed that acrylonitrile and guanidine react inDMF to yield not only 3,4,6,7-tetrahydro-2H-pyrimido[1,2—a]pyrimidine-2,8(1H)-diimine (1), but a mixture (F) of1 (as a main product) and 2-amino-4-imino-1,4,5,6-tetrahydropyrimidine-1-propionitrile (7) besides one or two bases not identified so far.1 and7 were isolated as picrates. For the prove of their structures,1- and7-picrate were also prepared by an unequivocal synthesis starting from iminodipropionitrile hydrochloride8 · HCl: The latter on reaction with cyanamide gave9 which cyclized to afford a mixture of1,7 and 2-amino-4-oxo-1,4,5,6-tetrahydropyrimidine-1-propionitrile (10). The picrates of1 and7 were identical with those prepared from the acrylonitrileguanidine-condensateF. This result supports the prior proposed¹ structures of pyrimidopyrimidine1 and of4,5 and6, obtained by hydrolysis of1. Nmr-, ir-and some of the mass spectra of1,4,7–10 (and their salts) are reported.

     

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.

     

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.

     

Investigation of the Addition of Benzenethiol to p-Chlorophenylphenylacetylene

The addition of benzenethiol to p-chlorophenylphenylacetylene results in the formation of a mixture of two pairs of diastereomeric (E)- and (Z)-1-p-chlorophenyl-2-phenyl-1-phenylthioethylenes (1 and 2) and (E)- and (Z)-1-p-chlorophenyl-2-phenyl-2-phenylthioethylenes (3 and 4). The configurations of these compounds have been established by ¹ H NMR studies, by their preparation from benzyl p-chlorophenyl ketone and p-chloro-benzylphenyl ketone, and by the oxidation of the thioethylenes 1, 2, 3, and 4 to the corresponding sulphonylethylenes 5, 6, 7, and 8, respectively.     

Synthesis of partially saturated N-substituted 4H-3,1-benzothiazine-2(1H)-thiones

Summary Acid-catalyzed reaction of 2-arylidenecyclohexanones1 with N-substituted dithiocarbamic acids2 gave open-chain addition products3 and4. Dehydration of3 and4 afforded only one of the three possible isomeric N-substituted 4H-3,1-benzothiazine-2(1H)-thiones5 and6.

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Synthese von partiell gesättigten N-substituierten 4H-3,1-Benzothiazin-2-(1H)-thionen

Zusammenfassung Die säurekatalysierte Reaktion von 2-Arylidencyclohexanonen1 mit N-substituierten Dithiocarbaminsäure2 ergab die offenkettigen Additionsprodukte3 und4. Die Dehydratation von3 und4 führte ausschließlich zu einem der drei möglichen N-substituierten 4H-3,1-Benzothiazin-2(1H)-thion-Isomeren5 und6.