Solvent effects on the oxidative free radical reactions of 2-amino-1,4-naphthoquinones

Solvent effects on the manganese (III) initiated oxidative free radical reactions of 2-amino-1,4-naphthoquinones are described. This free radical reaction provides a novel method for the synthesis of benzo[f]indole-4,9-diones, benzo[f]indole-2,4,9-triones, benzo[b]carbazole-6,11-diones and benzo[b]acridine-6,11-diones. High chemoselectivity was observed in different solvents.     

Synthesis of 1H-naphth[2,3-d]imidazole-4,9-diones by acid catalyzed cyclization of 2-Acylamino-3-amino-1,4-naphthoquinones

The conversion of 2-acylamino-3-amino-1,4-naphthoquinones (II) to the corresponding 2-substituted 1H-naphth[2,3-d]imidazole-4,9-diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3-(4′-chlorobutanonyl-amino)-3-amino-1,4-naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2-butanonaphth[2,3-d]imidazole-4,9-dione (V); whereas, treatment of lie with refluxing formic acid gave 2-(4′-chlorobutyl)-1H-naphth[2,3-d]imidazole-4,9-dione. Treatment of 2-substi-tuted 1H-naphth[2,3-d]imidazole-4,5-diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2-disubstituted naphth[2,3-d]imidazole-4,9-diones (VI). The spectral properties of I, II, V and VI as well as those of some 2-acylamino-3-chloro-1,4-naphthoquinones IV are discussed.     

A novel manganese(III) acetate mediated reaction between 2-benzoyl-1,4-naphthoquinones and 1,3-dicarbonyl compounds

A manganese(III)-mediated reaction between 2-benzoyl-1,4-naphthoquinones and 1,3-dicarbonyl compounds is described. This reaction provides an effective method for the synthesis of naphtho[2,3-c]furan-4,9-diones and naphthacene-5,12-diones, and it shows fair to high chemoselectivity depending on the electronic effect of the benzoyl group substituent on the reactants. With ethyl benzoylacetate and 1,3-diketones, the novel naphtho[2,3-c]furan-4,9-diones were produced effectively with high selectivity.     

New ‘2-phenylnaphthalene’-mediated synthesis of benzo[b]naphtho[2,3-d]furan-6,11-diones and 6-oxa-benzo[a]anthracene-5,7,12-triones: first total synthesis of 6-oxa-benzo[a]anthracen-5-ones

We describe here a novel synthesis of benzo[b]naphtho[2,3-d]furan-6,11-diones based on the heteroannulation of 2-(2-bromophenyl)-3-hydroxy-1,4-naphthoquinones. The naphthoquinones were prepared from 3-(2-bromophenyl)naphthalen-2-ols, which were obtained by intramolecular aldol condensation of 2-[3-(2-bromophenyl)-2-oxo-propyl]benzaldehydes. Alternatively, benzo[b]naphtho[2,3-d]furan-6,11-diones were obtained more directly and efficiently by cyclization of 3-(2-bromophenyl)naphthalen-2-ols to benzo[b]naphtho[2,3-d]furans and oxidation of the resulting compounds. Furthermore, the first 6-oxabenzo[a]anthracen-5-one described was similarly obtained from 2-[3-(2-formylphenyl)-2-oxopropyl]benzoic acid and oxidized to 6-oxa-benzo[a]anthracene-5,7,12-trione.     

DABCO-catalyzed three-component reaction for the synthesis of naphtho[2,3-b]thiophene-4,9-diones

An efficient synthesis of naphtho[2,3-b]thiophene-4,9-diones has been developed via DABCO-catalyzed three-component reaction of 1,4-naphthoquinone derivatives, α,β-unsaturated ketones and hydrated sodium sulfide. The reaction is initiated by sequential Michael additions of sodium sulfide to α,β-unsaturated ketone and of generated anion to 1,4-naphthoquinone derivative, followed by intramolecular oxidative cyclization and aromatization. Various functional groups in the α,β-unsaturated ketones survive under the reaction conditions and naphtho[2,3-b]thiophene-4,9-diones are generated in good yields.     

Synthesis of indan-based unusual alpha-amino acid derivatives under phase-transfer catalysis conditions

Conformationally constrained cyclic alpha-amino acid derivatives were synthesized under solid-liquid phase-transfer catalysis conditions. This methodology involves the bis-alkylation of ethyl isocyanoacetate with various alpha,alpha'-dibromo-o-xylene derivatives [alpha,alpha'-dibromo-o-xylene 5, 2,3-bis(bromomethyl)-1, 4-dimethoxybenzene 6, 1,2-bis(bromomethyl)-4,5-dibromobenzene 7, 2, 3-bis(bromomethyl)naphthalene 8, 1,8-bis(bromomethyl)-naphthalene 9, 6,7-bis(bromomethyl)-2,2-dimethyl-1H-phenalene-1,3(2H)-dione 10, 2, 3-bis(bromomethyl)-1,4-anthraquinone 11, 6, 7-bis(bromomethyl)quinoxaline 12, 3,4-bis(bromomethyl)furan 13, 1,2, 4,5-tetrakis(bromomethyl)benzene 28, and hexakis(bromomethyl)benzene 30] using potassium carbonate as a base and tetrabutylammonium hydrogensulfate as a phase-transfer catalyst to give corresponding isonitrile derivatives, which upon hydrolysis with HCl in ethanol gave amino esters. Using this method electron-deficient as well as electron-rich and halogen-substituted indan-based alpha-amino acids were prepared. The preparation of bis-indan as well as tris-indan alpha-amino esters is also described.     

Thermal decomposition of 2-amino-3-aziridino-1,4-naphthoquinones

The course of the thermal decomposition of various 2-amino-3-substituted aziridino-1,4-naphthoquinones (Ia-g) was investigated. In all the cases, the thermal decomposition gave variable amounts of 2,3-diamino-1,4-naphthoquinone (II) and of substituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxaline-5,10-diones (IIIa-g) with complete stereospecificity. The decomposition of the aziridines Ib,f also gave significative amounts of 2-amino-3-allylamino-1,4-naphthoquinones (IVb,f). In the case of 2-amino-3-(2′-phenyl-3′-ethylaziridino)-1,4-naphthoquinone (Ig), the formation of trans-1-phenyl-1-butene (V), 2-(1-phenylpropyl)-1H-naphtho-imidazole-4,9-dione (VI), 2-phenyl-3-ethyl-3,4,5,10-tetrahydrobenzo[g]quinoxaline-5,10-dione (VII), 2-phenyl-3-ethyl-5,10-dihydrobenzo[g]quinoxaline-5,10-dione (VIII), and a mixture of cis- and trans-4H-2,3,5,6-tetra-hydro-2-phenyl-3-ethyl-5-iminonaphtho[1,2-b]oxazin-6-one (IX) also occurred. Hypotheses concerning the mechanism and the steric course of this reaction are given. The reaction is a general method for the stereospecific synthesis of 2,3-disubstituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxalines.     

Five-membered 2,3-dioxoheterocycles: XC. Reaction of 4,5-bis(methoxycarbonyl)-1H-pyrrole-2,3-diones with enaminoesters. crystal and molecular structure of 4-methyl 9-ethyl 7-benzyl-3-hydroxy-8-methyl-1-(4-methoxyphenyl)-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-4,9-dicarboxylate

1-Aryl-4,5-bis(methoxycarbonyl)-1H-pyrrole-2,3-diones react with ethyl 3-(benzylamino)but-2-enoate and ethyl 3-(benzylamino)-3-phenylacrylate giving 4-methyl 9-ethyl 1-aryl-7-benzyl-3-hydroxy-8-methyl- and 4-methyl 9-ethyl 1-aryl-7-benzyl-3-hydroxy-8-phenyl-2,6-dioxo-1,7-diazaspiro[4.4]nona-3,8-diene-4,9-dicarboxylates.     

Structure Determination of New Isomeric Naphtho[2,3-b]furan-4,9-diones from Tabebuia avellanedae by the selective-INEPT technique

Beside the known naphthoquinones, dehydro-α-lapachone ( 17 ) and lapachol ( 20 ), four new naphtho[2,3-b]-furan-4,9-diones, i.e. the 2-acetyl-5-hydroxy. 2-acetyl-8-hydroxy. (?)-5-hydroxy-2-(1′-hydroxyethyl), and (±)-8-hydroxy-2-(1′-hydroxyethyl) derivatives 16, 15, 12 , and 13 , respectively, and the new compound benzo[b]furan-6-carboxaldehyde ( 8 ) have been isolated from a CHCl₃ extract of the inner stem bark of Tabebuia avellanedae LORENTZ ex GRISEB ., together with four known naphthofurandiones, a dihydroisocoumarin derivative, (?)–6-hydroxymellein, and five benzoic-acid and three benzaldehyde derivatives which have not been reported previously from this plant. Structure determination of the isomeric 5- and 8-hydroxynaphtho[2,3?b]furan-4,9-diones was carried out unambiguously by a combination of selective-INEPT experiments and X-ray crystallographic analysis.     

Photoinduced Molecular Transformations. Part 142. One-step syntheses of 1H-benz[f]indole-4,9-diones and 1H-indole-4,7-diones by a new regioselective photoaddition of 2-amino-1,4-naphthoquinones and 2-amino-1,4-benzoquinones with alkenes

The 2,3-dihydro-1H-benz[f]indole-4,9-diones 3a–d , h were formed in a one-step reaction in 13–82% yield by an unprecedented [3 + 2] regioselective photoaddition of 2-amino-1,4-naphthoquinone ( 1 ) with various electronrich alkenes 2 (Scheme 1, Table). The [3 + 2] photoadducts derived from 1 with vinyl ethers and vinyl acetate gave 1H-benz[f]indole-4,9-diones 4e , f , i , in 33–72% yield, by spontaneous loss of the corresponding alcohol or AcOH from the resulting adducts; 4i has a kinamycin skeleton. The [3 + 2] photoaddition also took place on irradiation of the differently substituted amino-1,4-benzoquinones 6 , 7 , and 12 and excess alkenes 2 in benzene, giving 1H-indole-4,7-dione derivatives 13 and 14 (Scheme 3), 15a and 16 (Scheme 4), and 18 (Scheme 4), respectively. The initial products in these photoadditions were proved to be hydroquinones, the air oxidation of which yielded the heterocyclic quinones; 2,3-dihydro-2-methoxy-2-methyl-5-phenyl-1H-indole-1,4,7-triyl triacetate ( 19 ) was isolated after treatment of the crude photoaddition mixture obtained from 2-amino-5-phenyl-1,4-benzoquinone ( 7 ) and 2-methoxyprop-1-ene ( 2f ) with Ac₂O and pyridine under N₂. A pathway leading to the annelated hydroquinones involving ionic intermediates arising from an electron transfer in these photoadditions is proposed (Scheme 5).     

7-氯-[1，2，3，4]-四氢吩嗪-[2，3]-并富勒烯[60]的合成

60富勒烯及其衍生物因其结构的特殊性,在有机超导、分子磁性、有机发光材料、分子器件、非线性光学活性、能量代谢和生物活性等[1]方面表现出独特的性能和潜在的应用前景,是非常活跃的研究领域之一.     

Photo-induced molecular transformations. Part 123. One-step synthesis of 1H-benz[f]indole-4,9-diones by a new regioselective photoaddition of 2-amino-1,4-naphthoquinone with various alkenes and its application to one-step synthesis of kinamycin skeleton

2,3-Dihydro-1H-benz[f]indole-4,9-diones are formed in one-step in 45–82% yields by an unprecedented [2+3]-type regioselective photoaddition of 2-amino-1,4-naphthoquinone with various electron-rich alkenes and the [2+3] adducts derived from ammonaphthoquinone with vinyl ethers and vinyl acetate to give 1H-benz[f]indole-4,9-diones including a benzindole-dione with a kinamycin skeleton in 33–72% yields. A probable pathway leading to the formation of the dihydroindole-dione involving air oxidation of an intermediary hydroquinone is proposed.     

A simple synthesis of 4‐chloro‐5‐hydroxy‐1H‐benzo[g]indoles

The reaction of methyl 2‐(3‐chloro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)propenoate ( 2a ) with primary amines gave 4‐chloro‐5‐hydroxy‐3‐methoxycarbonyl‐1H‐benzo[g]indoles 5a‐f as major compounds and 3‐methoxycarbonyl‐4,9‐dioxo‐2,3,4,9‐tetrahydro‐1H‐benzo[f]indoles 6a‐d as minor ones. Whereas the reaction of 3‐(3‐chloro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐yl)‐3‐buten‐2‐one ( 2b ) with primary amines afforded the corresponding 1H‐benzo[g]indoles 5g‐i as major products and 3‐acetyl‐4,9‐dihydro‐4,9‐dioxo‐1H‐benzo[f]indoles 7g, h as minor products.     

Synthesis of 2-aryl-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-diones by reaction of 2-benzylamino-1,4-naphthoquinones with nitric acid

2-Aryl-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-diones were synthesized by treatment of 2-benzylamino-1,4-naphthoquinones with a mixture of nitric and sulfuric acids in acetic acid.     

Transformations of 2-alkylamino-1,4-naphthoquinones under the action of nitrating mixture in acetic acid

Reactions of 2-alkylamino-1,4-naphthoquinones with a nitrating mixture in acetic acid afforded 2-alkyl-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-diones.     

Synthesis and base-catalyzed cleavage of 1-aryl-4,9-dioxo-1H-naphtho[2,3-d][1,2,3]triazole 2-oxides

A method was developed for the synthesis of 1H-1-arylnaphtho[2,3-d][1,2,3]triazole-4,9-dione 2-oxides based on 2-arylamino-3-chloro-1,4-naphthoquinones. The reaction of 1H-1-arylnaphtho[2,3-d][1,2,3]triazole-4,9-dione 2-oxides with an ethanolic alkali solution affords 2-{[1-(aryl)-2-oxido-1H-1,2,3-triazol-4-yl]carbonyl}benzoic acids.     

Synthesis of substituted benz[<Emphasis Type="Italic">g</Emphasis>]indole-6,9-diones and benzo[<Emphasis Type="Italic">h</Emphasis>]quinoline-7,10-diones by heterocyclization of 6-alkynyl-5-amino-1,4-naphthoquinones

Substituted benz[g]indole-6,9-diones were synthesized by intramolecular cyclization of 6-alkynyl-5-amino-3-diethylamino-1,-4-naphthoquinones. A method was developed for the preparation of 2-aryl(or alkyl)-4,9-bis(dialkylamino)benzo[h]quinoline-7,10-diones, which involves the addition of a secondary amine to 6-acylethynyl-5-amino-3-diethylamino-1,-4-naphthoquinone followed by cyclization of the resulting adduct.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 412–418, February, 2005.     

Synthesis and calculated properties of some 1,4-bis(amino)anthracene-9,10-diones

The synthesis of a number of 1,4-bis(amino)anthracene-9,10-diones containing chlorine or sulfur which are related to the anti-cancer drugs Ametantrone and Mitoxantrone are reported. 1,4-Dichloro-2,3-dihydro-5,8-dihydroxyanthracene-9,10-dione reacts readily with a series of alkylamines to yield the corresponding 1,4-bis(alkylamino)-5,8-dichloroanthracene-9,10-dione after oxidation. The subsequent reaction of the products with ethanethiol or thiophenol gives the corresponding 1,4-bis(alkylamino)-5,8-bis(sulfanyl)anthracene-9,10-dione in good yield. Theoretical calculations at the RHF 6-31G** level indicate that the introduction of either chlorine or the phenylsulfanyl group into the 5- and 8-positions of 1,4-bis(alkylamino)anthracene-9,10-diones results in a lowering of the LUMO energies suggesting that related functionalised derivatives might have lower cardiotoxicities than Mitoxantrone.     

Studies on the syntheses of heterocycles from 3-arylsydnone-4-carbohydroximic acid chlorides with N-arylmaleimides, [1,4]naphthoquinone and aromatic amines

3-Arylsydnone-4-carbohydroximic acid chlorides (1) could react with N-arylmaleimides (3a–b) or 2-methyl-N-phenylmale-imide (3c) to give 3-(3-arylsydnon-4-yl)-5-aryl-3a,6a-dihydro-pyrrolo[3,4-d]isoxazole-4,6-diones (4a–h) or 6a-methyl-3-(3-arylsydnon-4-yl)-5-phenyl-3a,6a-dihydro-pyrrolo[3,4-d]isoxazole-4,6-diones (4i–l), respectively. However, 3-(arylsydnon-4-yl)-naphtho[2,3-d]isoxazole-4,9-diones (6a–d) were obtained in good yield by the reaction of carbohydroximic acid chlorides 1 with [1,4]naphthoquinone. Furthermore, 2-(3-arylsydnon-4-yl)benzoxazoles (9a–d) and 2-(3-arylsydnon-4-yl)benzothiazoles (9e–h) were obtained via the reaction of carbohydroximic acid chlorides 1 with ortho-substituted aromatic amines 7a and b.     

Synthesis of Functional Derivatives of Benzofuran-5,6-dicarboxylic Acids

Russian Journal of General Chemistry - Synthetic routes to novel substituted benzofuran-5,6-dicarboxylic acids and furo[2,3-f]isoindole-5,7-diones via acid hydrolysis of the corresponding...