Benzologs of the thiazolo[3,2-a]pyridinium system

By use of concentrated sulfuric acid rather than hydrobromic acid as the cyclizing medium, good yields of the thiazolo[3,2-a]quinolinium ion and its derivatives may be obtained from α-(2-quinolylthio) ketones or acetals. In the same way, α-(1-isoquinolylthio) and α-(6-phenanthridylthio) ketones afford thiazolo[2,3-a]isoquinolinium and thiazolo-[3,2-f]phenanthridinium salts.     

1,3-Dipolar Cycloaddition of Difluoro-Substituted Azomethine Ylides. Synthesis and Transformations of 2-Fluoro-4,5-dihydropyrroles

2-Fluoro-4,5-dihydropyrrole-3,4-dicarboxylic acid derivatives were obtained by reaction of difluorocarbene with N-substituted ketone imines in the presence of fumaronitrile, maleonitrile, or dimethyl maleate. The reaction involves intermediate formation of azomethine ylides and their subsequent cycloaddition at the double bond. 11H-Dibenz[b,e]azepine and 3,4-dihydroisoquinolines react with difluorocarbene in the presence of fumaronitrile to give fluoro-substituted dibenzo[c,f]pyrrolo[1,2-a]azepine and pyrrolo[2,1-a]-isoquinoline derivatives. Treatment of 2-fluoro-4,5-dihydropyrrole-3,4-dicarbonitrile with amines and alkoxides affords the corresponding 2-amino- and 2-alkoxy derivatives, while its reactions with hydrazine hydrate and benzimidamide lead to formation of substituted pyrrolo[2,3-c]pyrazole and pyrrolo[2,3-d]-pyrimidine derivatives.     

Synthesis of derivatives of thiazolo[2,3-i]purine

Thiazolo[2,3-i]purine and its 7,8-alkyl(aryl, heteryl)derivatives were obtained by the cyclodehydration of 7hydroxy-7, 8-dihydrothiazolo[2, 3-i)purine and 6--oxoalkyl (aryl, heteryl)thiopurines in the presence of phosphoryl chloride, sulfuric, and polyphosphoric acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 265–270, February, 1996.     

A facile synthesis of [1,2,4]triazino[3,2-f]purines and [1,2,4]triazepino[3,2-f]purines

[1,2,4]Triazino[3,2-f]purines 3a-e and [1,2,4]triazepino[3,2-f]purine 5 were synthesized by the reaction of 7,8-diamino-1,3-dimethylxanthine 1 with diketones such as glyoxal, diacetyl, dibenzoyl, pyruvic aldehyde dimethyl acetal, phenylglyoxal or acetylacetone in acetic acid in the presence of boric acid or polyphosphoric acid.     

Synthesis of benzo[<Emphasis Type="Italic">f</Emphasis>]quinoline derivatives by three-component condensation of tetronic acid with naphthalen-2-amine and formaldehyde

New derivatives of benzo[f]furo[3,4-b]quinoline, spiro[benzo[f]quinoline-2,3′-furan], and benzo[f]-quinoline-2-carboxylic acid were synthesized with high selectivity by three-component condensation of tetronic acid with naphthalen-2-amine and formaldehyde.     

Quinazolincs and 1,4-benzodiazepines. LXXXVI. The synthesis of imidazothienodiazepines and imidazopyrazolodiazepines

The thieno[3,2-e][1,4]diazepin-2-one ( 1a ), the thieno[2,3-e] [ 1,4] diazepin-2-one ( 1b ), the pyrazolo[3,4-e][1,4]diazepin-2-one ( 1c ) and a chloro analog of 1b , compound 1d , were each converted to derivatives of the novel tricyclic ring systems 4H-imidazo[1,5-a]thieno[2,3-f] [1,4]-diazepine, 4Himidazo[1,5a]thieno[2,3f][1,4]diazepine and 4H-imidazo[ 1,5-a]pyrazolo[4,3-f]-[1,4]diazepine. Depending on the substituents desired on the imidazo ring, two different synthetic pathways were employed.     

Synthesis and Photochromic Behaviour of Naphthopyrans,Pyranoquinolines, Pyranoquinazolines and Pyranoquinoxalines

New chromenes annulated with different six-membered azaheterocycles were prepared, i.e., the 3H-pyra-no[3,2-f]quinolines 9/10 and 14 , the 8H-pyrano[2,3-h]isoquinoline 11 , the 8H-pyrano[3,2-f]quinazolme 12 , the 8-H-pyrano[3,2-f]quinoxaline 13 , and the 2H-pyrano[2,3-f]isoquinoline 15. The synthesis was achieved using conveniently substituted α,β-unsaturated aldehydes and organotitanium intermediates arising from azaheterocyclic phenols. Their photochromic behaviour (photocolouration yield, UV/VIS spectrum of photomerocyanines, rate constant of thermal bleaching) were studied besides those of corresponding naphthopyrans. The heterocycle effect and the role of substituents in the pyran moiety were investigated quantitatively through the study of the photochromic properties and the solvent effects. Diaryl-substituted azino-fused chromenes, especially isoquinoline derivatives, exhibit increased colourabilities and bathochromically shifted spectra for photomerocyanines which open up new prospects for photochromic applications.     

The synthesis of some pyrido[1,4] benzoxazepines and a dipyrido[1,4] oxazepine

Synthetic routes to pyrido[2,3-b]-, pyrido[4,3-b]-, pyrido[3,2-f] [1,4]benzoxazepines and dipyrido[2,3-b:2,3-f] [1,4]oxazepine are described. The applicability of one of the methods to dibenz[b,f] [1,4]oxazepine synthesis is discussed.     

Heterocyclic analogs of 5,12-naphthacenequinone 9*. Study of the synthesis and reactivity of 4,11-dimethoxynaphtho[2,3-<Emphasis Type="Italic">f</Emphasis>]isatin-5,10-diones

A preparative method has been developed for N-alkyl 4,11-dimethoxynaphtho[2,3-f]isatin-5,10-diones. Condensation reactions with several N- and C-nucleophiles have been carried out to give the corresponding derivatives at position 3. An efficient method has been discovered for the demethylation of the N-alkyl-4,11-dimethoxynaphtho[2,3-f]isatin-5,10-diones to give a high yield of N-substituted 4,11-dihydroxynaphtho[2,3-f]isatin-5,10-diones. Successive halogenation using phosphorus penta-chloride and acylation of tert-butylamine by the intermediate 2-chloro derivative converted 4,11-di-methoxynaphtho[2,3-f]isatin-5,10-dione to the 2-amino-3H-naphtho[2,3-f]indole-3,5,10-trione derivative.     

L-Proline catalyzed three component synthesis of pyrano[2,3-c]pyrazole-5-carbonitrile derivatives and in vitro antimalarial evaluation

An efficient one-pot synthesis of 6-amino-4-(2-chloroquinolin-3-yl)-3-methyl-2, 4-dihydro-pyrano[2,3-c]pyrazole-5-carbonitrile derivatives (4a–f)(5a–f) by three component reactions of 2-chloroquinolin-3-carbaldehyde derivatives, malanonitrile, and 3-methyl pyrazolin-5-one derivatives catalyzed by L-proline in ethanol medium under mild conditions is established. The synthesized compounds were evaluated for antimalarial activity and the LC₅₀/LC₉₀ values were described. Compounds 4d, 5d, and 5f exhibits good antimalarial activity when compared to other pyrano[2,3-c]pyrazole scaffolds.     

Synthesis and structure of 3,7-dihydro-2h-1,2,4-triazolo-[1′,5′-a′]tripyrimido[4,5-d]benzo[bpyrans

The condensation of 5-(2-hydroxyphenyl)-6, 7-dihydro-1, 2, 4-triazolo[l, 5-a]pyrimidines with aldehydes yields derivatives of a new heterocyclic system, namely, 3,7-dihydro-2H-1,2,4-triazolo[1,5-a]pyrimido[4,5-d]-benzo[b]pyran, including the 9-methyl-2,3-diphenyl derivative, whose structure was established by x-ray diffraction structural analysis.*Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2. pp. 240–246, February, 1996.     

Multicomponent condensation of 6-acetyl-5,7-dihydroxy-4-methylchromen-2-one with aldehydes and Meldrum´s acid

Previously unknown 6-acetyl-10-aryl-5-hydroxy-4-methyl-9,10-dihydropyrano[2,3-f]-chromene-2,8-diones were synthesized by multicomponent condensation of 6-acetyl-5,7-dihydroxy-4-methylchromen-2-one, aromatic aldehydes, and Meldrum´s acid. A fundamen-tal possibility of interconversion of substituted 6-acetyl-10-aryl-5-hydroxy-4-methyl-9,10-dihydropyrano[2,3-f]chromene-2,8-diones and methyl 3-(6-acetyl-5,7-dihydroxy-4-meth-yl-2-oxo-2H-chromen-8-yl)-3-arylpropionates was demonstrated.     

N-substituierte Aminomethylen-tetralone,-indandione und-indanone Beiträge zur Chemie der Enaminoketone, 6. Mitt

Zusammenfassung Die Synthese einer Reihen euer Enaminoketone, welche sich vom Aminomethylen-tetrahydronaphthalinon,-indandion bzw.-indanon ableiten, wird beschrieben. Diese Verbindungen haben die Eigenschaften von pH-Indikatoren und z. T. Farbstoff-charakter. Durch Kondensation mit Amino-pyridinen,-pyrimidinen bzw. Aminopyrazolen werden Naphtho[2,1-c][1,6]-naphthyridine, Benzo[f]pyrimido[4,5-c]isochinoline, Benzo-[h]pyrazolo[2,3-a]chinazoline, Indeno[2,1-c][1,6]naphthyridine bzw. Indeno[1,24,5]pyrido[2,3-d]pyrimidine erhalten.

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Enaminoketones, VI: N-substituted aminomethylene-tetralones,-indandiones and-indanones

The syntheses of aminomethylene-tetrahydronaphthalinones,-indanediones and-indanones are reported. The properties of these enaminoketones as pH-indicators and dyes are discussed. By condensation with amino-pyridines,-pyrimidines or aminopyrazoles naphtho[2.1-c][1.6]naphthyridines, benzo[f]pyrimido-[4.5-c]isoquinolines, benzo[h]pyrazolo[2.3-a]quinazolines, indeno[2.1-c][1.6]naphthyridines and indeno[1,24.5]pyrido-[2.3-d]pyrimidines, resp., are formed.

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Herrn Dr.Guido Schetty, Ciba-Geigy AG, Basel, zum 60. Geburtstag gewidmet.     

Condensed Imidazo-1,2,4-azines. 31. Synthesis and Chemical Transformations of Substituted 1,2,4-Triazepino[2,3-a]benzimidazoles

By reaction of 1,2-diaminobenzimidazole with 1,3-diketones, acetoacetic ester and its derivatives, we have synthesized substituted 1,2,4-triazepino[2,3-a]benzimidazole and 5H-1,2,4-triazepino[2,3-a]benzimidazol-4-one. By reaction of 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazol-4-one with aromatic aldehydes or phenyldiazonium chloride, we have obtained 3-arylidene(phenylazo) derivatives of this compound, and by reaction with P₂S₅ we have obtained 5H-2-methyl-1,2,4-triazepino[2,3-a]benzimidazole-4-thione. We have shown that when reacted with ammonia, primary or secondary amines, the latter forms 4-amino-substituted 2-methyl-1,2,4-triazepino[2,3-a]benzimidazole.     

Heterocyclic analogs of 5,12-naphthacenequinone 7*. Synthesis of naphtho-[2,3-f]isatin-5,10-dione derivatives

On chlorination of 4,11-dimethoxynaphtho[2,3-f]indole-5,10-dione with sulfuryl chloride in chloroform, its mono-, di-, and trichloro derivatives are formed depending on the conditions. Hydrolysis of the di- and trichloro derivatives gives a new polycondensed derivative of isatin, 4,11-dimethoxynaphtho-[2,3-f]isatin-5,10-dione. Its demethylation occurs effectively on extended heating with HBr in acetic acid and leads to 4,11-dihydroxynaphtho[2,3-f]isatin-5,10-dione (4,11-di-hydroxynaphtho[2,3-f]indole-2,3,5,10-tetraone). *For Communication 6 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1532–1536, October, 2008.     

Synthesis and structures of benzo[<Emphasis Type="Italic">cd</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]indol-4(5<Emphasis Type="Italic">H</Emphasis>)-one derivatives

A procedure was developed for the synthesis of derivatives of the new heterocyclic system, benzo[cd]furo[2,3-f]indole, based on the cyclodehydration of 6-acylmethyloxy-1-alkyl-benzo[cd]indol-2(1H)-ones. Either 7- or 8-aryl derivatives of benzo[cd]furo[2,3-f]indol-4(5H)-ones can be prepared depending on the reaction conditions. The molecular and crystal structures of 7- and 8-phenylbenzo[cd]furo[2,3-f]indol-4(5H)-ones were established by X-ray diffraction.     

Tetracyclic systems: Synthesis of isoindolo[1,2-b]thieno-[2,3(3,2 or 3,4)-e][1,3]thiazocines and Isoindolo[2,1-a]thieno-[2,3(3,2 or 3,4)-f][1,4] and [1,5]diazocines

Cyclization of thioglycolic acids derivatives 3a-d gave isoindolo[1,2-b]thieno[2,3(3,2 or 3,4)-e][1,3]-thiazocines 4a-d . Isoindolo[2,1-a]thieno[2,3(3,2 or 3,4)-f][1,4] or [1,5]diazocines 10b or 11a-c were synthesized from Beckmann or Schmidt rearrangement of the ketones 7a-c .     

13C NMR spectra of 1,4,5,8-tetraazaphenanthrene derivatives

The ¹³C NMR spectra of 1,4,5,8-tetraazaphenanthrene (pyrazino[2,3-f] quinoxaline), eleven of its derivatives [2- and 3-chloro, -methoxy and -(1′-piperidino), 2,3-dichloro, -dimethoxy, -dimethyl and -di(1′-piperidino) and 9-methoxy] and of 1,4,5,8,9,12-hexaazatriphenylene (dipyrazino[2,3-f: 2′,3′-h]quinoxaline) have been assigned by {¹H} selective decoupling experiments, correlations and additivities of substituent-induced chemical shifts and proton–carbon coupling patterns. Assignments of proton spectra are extended.     

Antineoplastic anthraquinones. II. Design and synthesis of 1,2-Heteroannelated anthraquinones

Based on the “2-phenyinaphthalene-type” structural pattern hypothesis, a number of heterocycle-fused anthraquinones were designed by taking morindaparvin-A ( 2a ) as the lead structure. The compounds we synthesized and tested for antineoplastic activity include 1,2-alkylenedioxyanthraquinone, naphtho [2,3-f]-quinoxaline-7,12-dione, anthra[1,2-d]imidazole-6,11-dione and naphtho[2,3-f]quinoxaline-7,12-dione derivatives. Most of the synthesized anthraquinones possessed various degrees of anticancer activity. One of these compounds, 2-chloromethyl-1H-anthra[1,2-d]imidazole-6,11-dione ( 4b ), exhibited cytotoxic activity against all tested human carcinoma cell lines.     

Synthesis of novel substituted pyrano annulated flavones

A simple and efficient one pot method has been developed for the synthesis of some new functionalized pyrano fused flavone derivatives, alkyl 4,8-dioxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-10-carboxylates and dialkyl 4-oxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-8,9-dicarboxylates, from 7-hydroxy flavones and 7-hydroxy 8-formyl flavones using dialkylacetalynedicarboxylates in the presence of triphenyl phosphine. The structures of all synthesized compounds were elucidated by FT-IR, ¹H and ¹³C NMR and Mass spectral analysis.