Synthesen von Heterocyclen, 135. Mitt.: Chinolizine und Indolizine,VI: eine Synthese von 2-Hydroxy-benzo[a] chinolizin-4-onen

Zusammenfassung 2-Hydroxy-6,7-dihydro-4H-benzo[a]chinolizin-4-one (3a—p) werden durch Kondensation von 1-Alkyl-3,4-dihydro-isochinolinen (1a—g) mit Malonsäure-bis-2,4,6-trichlorphenylestern (2a—e) erhalten. Die Ausbeuten sowie die erforderlichen Reaktionszeiten und Temperaturen sind stark von der Art der Substituenten abhängig.

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Syntheses of heterocycles, CXXXV: Quinolizines and indolizines, VI. A synthesis of 2-hydroxy-4H-benzo[a]quinolizin-4-ones

The condensation of 1-alkyl-3.4-dihydro-isoquinolines (1a tog) with 2.4.6-trichlorophenyl malonates (2a—e) yields 2-hydroxy-6,7-dihydro-4H-benzo[a]quinolizin-4-ones (3a—p). Yields, required reaction-periods and temperatures are depending on the nature of the substituents present in the malonyl and isoquinoline residue.

     

Reissert compound studies. XXXI. Emetine analogs based on the reaction of the reissert anion with 1,3,4,6,7,11b-hexahydro-9, 10-dimethoxybenzo[a] quinolizin-2-ones

Reaction of the Reissert anion with the carbonyl group of 1,3,4,6,7,11b-hexahydro-9,10-dimethoxybenzo[a]quinolizin-2-one and with 3-ethyl-1,2,3,4,6,7-hexahydro-9,10-dimethoxy-11bH-benzo[a]quinolizin-2-carboxaldehyde give emetine analogs. This anion does not react with the carbonyl group of 3-aIkyl-1,3,4,6,7,11b-hexahydro-9,10-dimethoxybenzo[a]quinolizin-2-one but instead gives a rearrangement product and the benzoquinolizinone cyanohydrin.     

Synthesen von Heterocyclen, 81. Mitt.: Über substituierte Glyoxalhydrazone

Zusammenfassung 3-Phenylazo-4-hydroxy-2-oxo-indeno[1,2-b]pyran (4) läßt sich durch Erhitzen mit verd. Lauge zum 3-Hydroxyindenyl-(2)-glyoxal-2-phenylhydrazon (11) hydrolysieren, welches mit Phenylhydrazin unter Ringschluß zum 1,4-Dihydro-1-phenylindeno-[1,2-c]pyrazol-(3)-aldehydphenylhydrazon (21) reagiert.

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3-Phenylazo-4-hydroxy-2-oxo-indeno[1,2-b]pyran (4) is hydrolysed by heating in aqueous sodium hydroxide solution to 3-hydroxyindenyl-(2)-glyoxal-2-phenylhydrazone (11). This compound reacts with phenylhydrazine under ring closure to 1,4-dihydro-1-phenylindeno[1,2-c]pyrazol-(3)-aldehyde phenylhydrazone (21).

     

Saturated heterocycles, 75. Preparation of tetracyclic thiophene derivatives with bridgehead nitrogen. Synthesis of polymethylenethieno[2,3—d]dihydropyrrolo-, tetrahydropyrido- and tetrahydroazepino[1,2—a]pyrimidin-4-ones and -4-thiones

The following tetracyclic ring systems and their derivatives have been synthesized for pharmacological investigations: Trimethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and -4-thione (1 a, 5 a); Tetramethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and -4-thione (1 b, 1 j, 5 b); Pentamethylenethieno[2,3—d]dihydropyrrolo[1,2—a]pyrimidin-4-one and-4-thione (1 c, 5 c); Trimethylenethieno[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one and -4-thione (1 d, 5 d); Tetramethylenethieno[2,3—d]tetrahydropyrido[1,2,—a]pyrimidin-4-one and -4-thione (1 e, 5 e); Pentamethylenethieno[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one and -4-thione (1 f, 5 f); Trimethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one and -4-thione (1 g, 5 g); Tetramethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-on and -4-thione (1 h, 5 h); Pentamethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one and -4-thione (1 i, 5 i); Tentamethylenethieno[2,3—d]tetrahydroazepino[1,2—a]pyrimidin-4-one (7 b); Pentamethylenethieno-[2,3—d]tetrahydropyrido[1,2—a]pyrimidin-4-one (7 c).Compounds1 a–i were synthesized from 2-amino-3-ethoxycarbonyl-4,5-polymethylenethiophene2 a–c with the corresponding lactim ethers (3 a–c) in chlorobenzene in the presence of polyphosphoric acid (PPA). Compounds7 b and7 c were obtained in the reaction of -amino acid esters2 b and2 c with 2-bromopyridine (6). The thione derivatives (5 a–i) were prepared from compounds1 a–i with phosphorus(V) sulphide.Part 74:Szabó J, Fodor L, Szcs E, Bernáth G, Sohár P (1984) Pharmazie 39: 347.     

Zur Synthese von 4-Aminochinolinen durch intramolekulareFriedel—Crafts-Reaktion

Treatment of arylaminomethylene-malononitriles,-cyanoacetamides and--cyanoacetophenones with AlCl₃ yields substituted 4-aminoquinolines2, while quinolin-4-ones3 are obtained from ethyl arylaminomethylene cyanoacetates. N--naphthylcyanoacetamide reacts in the presence of AlCl₃ to form 1-amino-3-benzo[f]quinolinone (6). Isothiazolo[4,3–c]quinolines (10) and pyrimido[5,4–c]quinolines (11, 12) can be obtained from2. 4-Aminoquinoline-3-carboxylic acids derived from2, can be decarboxylated.3 are cyclized to form oxazino[5,6–c]-quinolinones (4).     

Über Reaktionen von Nitrosophenolen, 2. Mitt.: Reaktion von 1-Nitroso-2-naphthol mit Orein

Zusammenfassung In der vorliegenden Arbeit wurde die Reaktion von 1-Nitroso-2-naphthol mit Orcin in Äther bei Anwesenheit von HNO₃ studiert. Als Reaktionshauptprodukte wurden 11-Methylbenzo[a]-phenoxazon-(9) (1) sowie dessen 12-Oxid (2) isoliert. Der Reaktionsmechanismus und die Konstitution der erhaltenen Substanzen werden diskutiert. Ferner wurden auch 11-Methyl-5-hydroxy-benzo[a]phenoxazon-(9) (6), 11-Methyl-5-äthoxybenzo[a]phenoxazon-(9), 11-Methyl-5-methoxybenzo[a]phenoxazon-(9) (4), 11-Methyl-5-aminobenzo[a]phenoxazon-(9) (7) und 11-Methyl-5-anilinobenzo[a]phenoxazon-(9) (8) dargestellt.

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In this paper the reaction of 1-nitroso-2-naphthol with orcin in an ether medium in presence of HNO₃ is described. As main products 11-methylbenzo[a]phenoxazone-(9) (1) as well as its 12-oxide (2) were isolated. The reaction mechanism is presented. Identity of the reaction products is verified. 11-methyl-5-hydroxybenzo[a]phenoxazone-(9) (5), 11-methyl-5-methoxybenzo[a]phenoxazone-(9) (4), 11-methyl-5-aminobenzo[a]phenoxazone-(9) (7) and 11-methyl-5-anilinobenzo[a]phenoxazone-(9) (8) are prepared.

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Mit 2 Abbildungen     

synthesis of sempervirine,a pentacyclic anhydronium indole alkaloid

Summary Sempervirine (2,3,4,13-tetrahydro-1H-benz[g]indolo[2,3-a]quinolizin-6-ium,1) the pentacyclic anhydronium indole alkaloid ofGelsemium sempervirens Ait. f. (Loganiaceae), has been synthesized in three steps from hexahydroisochroman-3-one (6) and N-2-(3-indolyl)-ethylamine (tryptamine,7). The condensation product, N-2-(3-indolyl)-ethyl-2-(hydroxymethyl)-trans-hexahydrophenylacetamide (8) arising from6 and7 on double cyclization with phosphoryl chloride yielded the 3,4-dehydroyohimbane derivative9. Aromatization of rings C and D of compound9 with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in glacial acetic acid, followed by basification, generated sempervirine (1).

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Synthese von Sempervirin, einem pentacyclischen Anhydronium-Indolalkaloid

Zusammenfassung Sempervirin (2,3,4,13-Tetrahydro-1H-benz[g]indolo[2,3-a]chinolizin-6-ium,1), das pentacyclische Anhydronium-Indolalkaloid vonGelsemium sempervirens Ait f. (Loganiceae) wurde ausgehend von Hexahydroisochroman-3-on (6) und N-2-(3-Indolyl)-ethylamin (Tryptamin,7) in 3 Stufen synthetisiert. Das durch doppelte Cyclisierung von6 und7 mit Phosphorylchlorid entstehende Kondensationsprodukt N-2-(3-Indolyl)-ethyl-2-(hydroxymethyl)-trans-hexahydrophenylacetamid (8) ergab das 3,4-Dehydroyohimbanderivat9. Aromatisierung der Ringe C und D von9 mit 2,3-Dichlor-5,6-dicyanobenzochinon (DDQ) in Eisessig und anschließende Einstellung eines basischenpH-Werts lieferte Sempervirin (1).

     

On the chemistry of pyridazines,XXXVI: Novel diaza-analogs of 10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-one

Procedures for the preparation of the novel tricyclic ketones 10,11-dihydro-5H-benzo[4,5]cyclohepta[1,2—d]pyridazin-5-one (3), 5,6-dihydro-11H-benzo[4,5]cyclohepta[2,1—c]pyridazin-11-one (4), and 10,11-dihydro-5H-benzo[4,5]-cyclohepta[1,2—c]pyridazin-5-one (5) starting from a preformed 1,2-diazine system are proposed. The key intermediates7,19, and11 are prepared from (2-phenylethyl)pyridazines6 and18 by introduction of a carboxylic functionality via homolytic alkoxycarbonylation or via a sulfonylReissert-type reaction.

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Zur Chemie von Pyridazinen, 36. Mitt.: Neuartige Diazaanaloga des 10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-ons

Zusammenfassung Methoden zur Darstellung der neuen trizyklischen Ketone 10,11-Dihydro-5H-benzo[4,5]cyclohepta[1,2—d]pyridazine-5-on (3), 5,6-Dihydro-11H-benzo[4,5]cyclohepta[2,1—c]pyridazin-11-on (4) und 10,11-Dihydro-5H-benzo[4,5]cyclohepta[1,2—c]pyridazin-5-on (5) ausgehend von einem präformierten 1,2-Diazinsystem werden vorgeschlagen. Die Schlüsselbausteine dieser Synthesen7,19 und11 werden durch Einführung einer Carboxylfunktion in die (2-Phenylethyl)pyridazine6 und18 über homolytische Alkoxycarbonylierung bzw. eine Sulfonyl-Reissert-Reaktion erhalten.

     

Synthesen von Heterocyclen, 85. Mitt.: Über die α-Acyllactonumlagerung von 5-Benzoyl-dehydracetsäure

Zusammenfassung Die vonButt undElvidge aufgefundenen Isomeren, 4-Hydroxy-5-acetyl-6-phenyl-pyron-(2) (1) und 4-Hydroxy-5-ben-zoyl-6-methyl-pyron-(2) (2), ergeben bei der Umsetzung mit POCl₃ und Eisessig 5-Benzoyl-dehydracetsäure (3). Im Gegensatz zur Dehydracetsäure² reagiert 5-Benzoyl-dehydracetsäure (3) in alkohol. HCl zum 2,6-Dimethyl-3-äthoxycarbonyl-5-benzoyl-pyron-(4) (6). Die Struktur dieser Verbindung wird auf chemischem und physikalischem Wege abgeleitet.Mit wäßr. HCl läßt sich3 in 2,6-Dimethyl-5-benzoyl-pyron-(4) (5) umwandeln.

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The isomeric compounds¹ 4-hydroxy-5-acetyl-6-phenyl-pyron-2 (1) and 4-hydroxy-5-benzoyl-6-methyl-pyron-2 (2) yield 5-benzoyl-dehydroacetic acid (3) if with glacial acetic acid and POCl₃. In contrast to dehydroacetic acid² 5-benzoyl-dehydroacetic acid (3) reacts in ethanolic HCl to 2,6-dimethyl-3-carbethoxy-5-benzoyl-pyron-(4) (6).However, with aquenous HCl3 is converted to 2.6-dimethyl-5-benzoyl-pyron-(4) (5).

     

Synthesen von Heterocyclen, 101. Mitt.: Zur Chemie des 6-Chlor-4-hydroxy-2-oxopyran-3-carbonsäurechlorids

Zusammenfassung 6-Chlor-4-hydroxy-2-oxopyran-3-carbonsäurechlorid (1) reagiert mit N,N'-Di-p-tolyl-carbodiimid zum 7-Chlor-4,5-dioxo-3-p-tolyl-2-p-tolylimino-3,4-dihydro-2H,5H-pyrano[3,4-e][1,3]oxazin (3). Benzoxazol gibt mit1 in analoger Reaktion über6 die Verbindung7.

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6-Chloro-4-hydroxy-2-oxo-pyran-3-carboxylic acid chloride (1) reacts with N,N'-di-p-tolyl-carbodiimide yielding 7-chloro-4,5-dioxo-3-p-tolyl-2-p-tolylimino-3,4-dihydro-2H,5H-pyrano-[3,4-e] [1,3]oxazin (3). In an analogous reaction1 interacts with benzoxazol via6 to yield compound7.

     

Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives

Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methyl[2]benzopyrano[4,3-c]pyrazol-5-one (yield 10%), 1,4-dimethyl-3-phenylpyrazolo[3,4-c]isoquinolin-5-one (yield 10%), N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-hydroxybenzamide (yield 8%) and 4′-hydroxy-2,3′-dimethyl-1′-phenylspiro[isoindoline-1,5′-[2]-pyrazolin]-3-one (yield 20%). Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenylpyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]-diazocin-10-(9H)one (yield 8%), 4-methyl-1,3-diphenylpyrazolo[3,4-c]isoquinolin-5-one (yield 7%) and 4′-hydroxy-2-methyl-1′,3′-diphenylspiro[isoindoline-1,5′-[2]pyrazolin]3-one (yield 10%). The spiro compounds 6a,b underwent thermal and acid-catalysed conversion into the hitherto unknown 2-benzopyrano[4,3-c]pyrazole ring system 7a,b in good yield. Analytical and spectral data are presented which supported the structures proposed.     

Synthesen von Heterocyclen, 122. Mitt.: Über die Reaktion des Perimidons mit aktiven Malonestern

Zusammenfassung Perimidon (1) reagiert mit monosubstit. Malonsäure-trichlorphenylestern (2) bei 250° zu 9-Hydroxy-5,7-dioxo-4,5-dihydro-7H-pyrido[1,2,3-cd]perimidinen (3), die durch saure Hydrolyse zu 10-Amino-4-hydroxy-benzo[h]carbostyrilen (4) gespalten werden.

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Syntheses of heterocycles, CXXII: Reaction of perimidone with reactive malonates

Perimidone (1) reacts with monosubstituted 2.4.6-trichlorophenyl malonates at 250° to 9-hydroxy-5.7-dioxo-4.5-dihydro-7H-pyrido[1.2.3-cd]perimidines (3), which are cleaved by acid yielding 10-amino-4-hydroxy-benzo[h]quinolin-2-ones (4).

     

Synthesis and reactions of 2,3-dimethylfuro[3,2-c]pyridines

Summary A number of substituted 2,3-dimethylfuro[3,2-c]pyridines was synthesized. 3-(4,5-Dimethyl-2-furyl)propenoic acid (1) was converted to the acid azide2, which in turn was cyclized to give 2,3-dimethyl-5H-furo[3,2-c]pyridine-4-one (3) by heating at 240°C in Dowtherm. The pyridone3 was chlorinated with phosphorus oxychloride to give4, which was reduced with zinc and acetic acid to 2,3-dimethylfuro[3,2-c]pyridine (5). Treatment of4 with several secondary heterocyclic amines led to compounds6a–6c. Reaction of pyridone3 with phosphorus pentasulfide rendered the thione7, which was methylated to8a. The 4-methoxy derivative8b was obtained from4 with sodium methoxide. 2,3,5-Trimethylfuro[3,2-c]pyridine-4-one (9) was obtained by reaction of3 with methyl iodide.Dedicated to Professor Dr.Fritz Sauter on the occasion of his 65th birthday     

A study of the Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one derivatives

Summary The Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 a) gave 7-hydroxy-8-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (3 a) and 2,3-dihydro-2,6-diphenyl-3-methyl-(7H)furo[2,3-h]-1-benzopyran-7-one (7 a). 2-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 b) afforded4 b and7 b. 8-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (12) gave only the alkali soluble product 7-hydroxy-8-methyl-6-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (13).3 a,4 b, and13 were further cyclized in acidic medium to9 a,10 b, and14 followed by dehydrogenation.This paper is dedicated to Dr. F. M. Dean, Department of Organic Chemistry, Robert Robinson Laboratories, University of Liverpool, Liverpool, U. K., on his retirement     

Ozonolyse von Olefinen,III: Säurekatalysierte Ozonolyse von 3-Hexen-1,6-und 2-Penten-1,5-dicarbonylderivaten

Summary The ozonolysis of mono-unsaturated compounds containing the structural element =CH-CH₂-R [R=COOH, COOCH₃, CH(OCH₃)₂] was investigated. Reductive ozonolysis of (E)-3-hexene-1,6-dioic acid gives methyl 3,3-dimethoxypropanoate (2), whereas ozonolysis of dimethyl (E)-3-hexene-1,6-dioate (1a) and (Z)-1,1,6,6-tetramethoxy-3-hexene (1b) in a methanolic solution of HCl leads to a mixture of2, dimethyl malonate (3 a) and 1,1,3,3-tetramethoxypropane (3 b). The homologuos derivatives, dimethyl glutaconate (4 a) and 1,1,5,5-tetramethoxy-2-pentene (4 b), were ozonized to give mixtures of2, 3, dimethyl oxalate (5), methyl 2,2-dimethoxyacetate (6 a), and 1,1,2,2-tetramethoxyethane (6 b). The ratios of the various reaction products were determined by gas chromatography. In each case the formation of the bifunctional derivatives2 and6 a was favoured.

     

Synthesis of benzophenothiazinone derivatives from 2,3,5-trisubstituted-1,4-naphthoquinones with 2-aminothiophenol

The 1-substituted-5H-benzo[2,3-a]phenothiazin-5-one, 4-substituted-5H-benzo[6,5-a]phenothiazin-5-one and 6-substitutedbenzo[a][1,4] benzothiazino[3,2-c]phenothiazine derivatives were prepared by the condensation of 5-substituted-2,3-dichloro-1,4-naphthoquinones with 2-aminothiophenol. Reduction, acetylation and dehalogenation of the resulting compounds were carried out and the structures of the products were inferred from comparison with the authentic compound.     

Synthesis and Antimicrobial Activities of Some 6-Methyl-3-Thioxo-2,3-Dihydro-1,2,4-Triazine Derivatives

Abstract

4-Arylidene-imidazole derivatives (4a,b) were readily prepared by reacting 4-am- ino-6-methyl-3–thioxo-2,3–dihydro[1,2,4]triazin-5(4H)-one (1) with 4-arylidene-2-phenyl- 4H-oxazol-5-one (2). Reaction of 1 with some aromatic aldehydes in presence of triethylphosphite exclusively afforded the corresponding aminophosphonates 5a-c. Reaction of 1 with 3-phenyl-1H-quinazoline-2,4-dione (6a) and/or 3-phenyl-2-thioxo-2,3-dihydro- 1H-quinazolin-4-one (6b) gave 2-(6-methyl-5-oxo-3-thioxo-2,5-dihydro-3H-[1,2,4]triazin-4-ylimino)-3-phenyl-2,3-dihydro-1H-quinazolin-4-one (7). Moreover, on treating 1 with 2-phenylbenzo[d][1,3]thiazine-4-thione (8), 6-methyl-4-(2-phenyl-4-thioxo-4H-quinazolin-3-yl)-3-thioxo-3,4-dihydro-2H-[1,2,4]triazine-5-one (9) was obtained in 65% yield. Reaction of 1 with 4-sulfonylaminoacetic acid derivatives (10a,b) afforded the corresponding sulfonamides (11a,b), respectively. Acid hydrolysis of 11a afforded 7-aminomethyl-3-methyl[1,3,4]thiadiazole[2,3-c][1,2,4]triazin-4-one (12). 4-Amino-6-methyl-3-(morpholine-4-ylsulfanyl)-4H-[1,2,4]triazin-5-one (14) was prepared by reacting compound 1 with morpholine in presence of KI/I₂, while 3,3′-bis(4-amino-6-methyl-5-oxo-triazinyl)disulfide (16) was obtained by oxidation of 1 with lead tetraacetate. The antimicrobial activity of the products was evaluated against Gram-positive and Gram-negative bacteria as well as the fungus Candida albicans.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures, and tables.]     

Heterocyclic quinol-type fluorophores. Part 9: Effect of forming a continuous intermolecular hydrogen bonding chain between fluorophores on the solid-state fluorescence properties

Three heterocyclic quinol-type fluorophores with benzo[c]carbazol-6-one skeleton or benzo[b]naphtho[1,2-d]furan-6-one skeleton, 9-dibutylamino-5-hydroxy-5-phenyl-5,7-dihydro-benzo[c]carbazol-6-one (5a), 7-butyl-9-dibutylamino-5-hydroxy-5-phenyl-5,7-dihydro-benzo[c]carbazol-6-one (5b) and 9-dibutylamino-5-hydroxy-5-phenyl-5H-benzo[b]naphtho[1,2-d]furan-6-one (6c) have been synthesized and their photophysical properties have been investigated in solution and in the solid state. The fluorescence quantum yield (Φ) increases in the order of 5b (0.35)<5a (0.41)<6c (0.74) in 1,4-dioxane. On the other hand, the Φ value in the solid state increases in the order of 5a<<6C (0.03)<5b (0.07), which are much smaller than those in 1,4-dioxane. To elucidate the effects of molecular and crystal structures on the solid-state fluorescence properties, we have performed the semi-empirical molecular orbital calculations (AM1 and INDO/S) and X-ray crystallographic analysis. It was found that the formation of a continuous intermolecular hydrogen bonding between adjacent fluorophores is observed in the crystal of 5a, which is considered to cause a drastic fluorescence quenching in the solid state.     

Alkylierung ambidenter Heterocyclen-Anionen, 1. Mitt.: Über die Benzylierung des 4-Hydroxy-carbostyrils

Zusammenfassung 4-Hydroxy-carbostyrile (1a–c) werden mit Benzylchlorid inDMF bevorzugt zu den 4-Benzyloxy-carbostyrilen (2a–c) alkyliert. In wäßr. NaOH dagegen erhält man aus1a und1c als Hauptprodukt das 3,3-Dibenzyl-2,4-dioxo-1,2,3,4-tetrahydrochinolin (3).

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Alkylation of 4-hydroxy-quinol-2-ones (1a–c) with benzyl chloride inDMF in the presence of K₂CO₃ mainly gives the 4-benzylethers2a–c. However, carbon dialkylation takes place in aqueous NaOH and the main product of the reaction between benzylchloride and1a is 3.3-dibenzyl-2.4-dioxo-1.2.3.4-tetrahydro-quinoline3.

     

Struktur des Hydrazinolyseproduktes von N-(3-Oxo-1-isoindolinyliden)-alanin-äthylester

Hydrazinolysis of N-(3-Oxo-1-isoindolinyliden)alanin Ethyl Ester, Structure of the Product Treatment of N-(3-oxo-1-isoindolinyliden)alanin ethyl ester (6) with hydrazine hydrate leads to 4-methyl-2,3,4,6-tetrahydro[1,2,4]triazino[3,4-a]isoindole-3, 6-dione ( 8 , Scheme 3) and not to the previously postulated 6-hydroxy-2-methyl-2,3-dihydro-imidazo [2,1-a]phthalazin-3-one ( 7 , cf. [2]). The structure of 8 has been established by an independent synthesis as well as by the X-ray analysis of the reaction product 11 from 8 and 3-dimethylamino-2,2-dimethyl-2 H-azirine ( 1 , Scheme 4). A reaction mechanism for the formation of 8 from 6 is suggested in Scheme 5.