Heterocyclic Analogs of 5,12-Naphthacenequinone. 1. Synthesis of Heterocyclic Analogs Starting from 2,3-Diaminoquinizarine

The amination of 2-nitroquinizarine using hydroxylamine gives 2-amino-3-nitroquinizarine, which, upon reduction, gives previously unreported 2,3-diaminoquinizarine, a key intermediate in the synthesis of heterocyclic analogs of 5,12-naphthacenequinone, namely, 4,11-dihydroxyanthra[2,3-d]imidazole-5,10-dione (imidazoloquinizarine), 4,11-dihydroxyanthra[2,3-d][1,2,3]triazole-5,10-dione (triazoloquinizarine), and 5,12-dihydroxynaphtho[2,3-g]quinoxaline-6,11-dione (pyrazinoquinizarine). __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1081–1088, July, 2005.     

Heterocyclic analogs of 5,12-naphthacenequinone 6. Synthesis of 4,11-dimethoxy derivatives of anthra-[2,3-<Emphasis Type="Italic">b</Emphasis>]thiophene-5,10-dione and anthra[2,3-<Emphasis Type="Italic">d</Emphasis>]isothiazole-5,10-dione

Condensation of 2-formyl-or 2-cyano-3-chloro-1,4-dimethoxyanthraquinone with methyl thioglycolate in the presence of base gave methyl 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-dione-2-carboxylate and its 3-amino derivative respectively. Hydrolysis of the ester group in methyl 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-dione-2-carboxylate and subsequent decarboxylation of the carboxylic acid formed gave 4,11-dimethoxyanthra[2,3-b]thiophene-5,10-dione. Condensation of 3-chloro-2-formyl-1,4-dimethoxyanthraquinone with ammonia in the presence of sulfur gave 4,11-dimethoxyanthra[2,3-d]isothiazole-5,10-dione __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 538–543, April, 2007.     

Heterocyclic analogs of 5,12-naphthacenequinone. 4. Synthesis of 4,11-dimethoxy-anthra[2,3-d]isoxazole-5,10-dione

A preparative synthetic method has been developed for 3-chloro-2-formyl-1,4-dimethoxyanthraquinone starting from available 2-methylquinizarine. The condensation of the α-chloroaldehyde obtained with acetone oxime gives 4,11-dimethoxyanthra[2,3-d]isoxazole-5,10-dione. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1421–1427, September, 2006.     

Heterocyclic analogs of 5,12-naphthacenequinone 8.* Synthesis of furano-anthraquinones

During the condensation of 2,3-dichloroquinizarine with methyl pivaloylacetate in the presence of potassium carbonate in dimethyl sulfoxide the main reaction products are derivatives of angular 3-pivaloylanthra[1,2-b]furan-2,6,11(3H)-trione (about 70%) and anthra[2,1-d][1,3]dioxole-6,11-dione (15%), whereas the yield of the targeted linear methyl 2-tert-butyl-4,11-dihydroxyanthra[2,3-b]furan-5,10-dione-3-carboxylate is only 2%. Methods are developed for modification of the obtained 3-pivaloylanthra[1,2-b]furan-2,6,11(3H)-trione, making it possible to use it for the synthesis of the tert-butyl derivatives of linear anthra[2,3-b]furan-5,10-dione or angular anthra[1,2-b]furan-6,11-dione. *For Communication 7 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 191–202, February, 2009.     

Heterocyclic analogs of 5,12-naphthacene-quinone. 3. Synthesis of 4,11-diaminonaphtho-[2,3-f]indole-5,10-dione and certain of its derivatives

Nucleophilic substitution of methoxy groups in 4,11-dimethoxynaphtho[2,3-f]indole-5,10-dione by the action of primary and secondary alkylamines, or arylamines leads to the formation of N-alkyl or N-aryl derivatives of 4,11-diaminonaphtho[2,3-f]indole-5,10-dione respectively. 4,11-Diamino-1H-naphtho-[2,3-f]indole-5,10-dione is obtained by the dealkylation of 4,11-bis[(1-phenylethyl)amino]-1Hnaphtho[ 2,3-f]indole-5,10-dione in the presence of a Lewis acid (BBr₃). __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 854–861, June, 2006.     

Synthesis of thiopheno-quinizarine derivatives

4,11-Dihydroxyanthra[2,3-b]thiophene-5,10-dione (thiophenoquinizarine) and its 3-methyl derivative were obtained by the cyclization of quinizarin-2-yl derivatives of mercaptoacetaldehyde or mercaptoacetone in acid medium. 4,11-Dimethoxy-and 4,11-dibutoxyanthra[2,3-b]thiophene-5,10-dione were synthesized by the alkylation of the hydroxyl group in the synthesized anthrathiophenes with dimethylformamide dimethylacetal or butyl iodide respectively. Radical bromination of 4,11-dimethoxy-3-methylanthra[2,3-b]thiophene-5,10-dione, depending on the amount of N-bromo-succinimide taken, leads to the formation of 3-bromomethyl-or 3-dibromomethyl-4,11-dimethoxy-anthra[2,3-b]thiophene-5,10-diones. The action of sodium acetate on the obtained bromo derivatives with subsequent hydrolysis of the intermediate acetates led to the synthesis of 3-hydroxymethyl-or 3-formyl-4,11-dimethoxy-anthra[2,3-b]thiophene-5,10-diones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1478–1485, October, 2007.     

Naphthoindoles. 10. Synthesis of 4,11-Dihydroxynaphtho[2,3-f]indole-5,10-dione and Some of Its Derivatives

4,11-Dihydroxynaphtho[2,3-f]indole-5,10-dione (pyrroloquinizarin), its 11-dehydroxy derivative, and Mannich base were synthesized by demethylation of previously obtained methoxynaphtho[2,3-f]indole-5,10-diones.     

Naphthoindoles. 9. Synthesis of N-derivatives of 4,11-Dimethoxynaphtho-[2,3-f]indole-5,10-dione

N-Acetylation and several N-alkylation reactions have been carried out for the previously synthesized 4,11-dimethoxynaphtho[2,3-f]indole-5,10-dione.     

Heterocyclic analogs of 5,12-naphthacenequinone. 2. Synthesis of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione and its n-methyl derivatives

On methylating 4,11-dimethoxynaphtho[2,3-f]indazole-5,10-dione with methyl iodide in the presence of base a mixture is formed of its 1-and 2-methyl derivatives. Demethylation of the methoxy groups of the starting material and of the products of its alkylation leads to the formation of 4,11-dihydroxynaphtho[2,3-f]indazole-5,10-dione (pyrazoloquinizarine) and its 1-and 2-methyl derivatives. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–696, May, 2006.     

Pd-catalyzed cross-coupling/heterocyclization domino reaction: facile access to anthra[2,3-b]furan-5,10-dione scaffold

A new facile route to the synthesis of 4,11-dimethoxyanthra[2,3-b]furan-5,10-dione and its novel 2-substituted derivatives was proposed. The developed scheme was based on a Pd-catalyzed cross-coupling/heterocyclization domino reaction of 3-bromo-2-hydroxy-4,11-dimethoxyanthraquinone with terminal alkynes.     

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.     

Naphthoindazoles. Synthesis of 4,11-Dimethoxynaphtho[2,3-f]indazole-5,10-dione

The previously unknown 4,11-dimethoxynaphtho[2,3-f]indazole-5,10-dione has been obtained by the thermal cyclization of N-nitroso derivative of 2-acetamido-3-methyl-1,4-dimethoxyanthraquinone.     

Heterocyclic analogs of 5,12-naphthacenequinone 10.* Synthesis of furanoquinizarine and its new derivatives

A new method was developed for synthesis of anthra[2,3-b]furan-5,10-dione derivatives. The key compound for annelation of the furan fragment to the anthraquinone chromophor is the previously unknown analog of salicylaldehyde, 1,4-dimethoxy-3-formyl-2-hydroxyanthraquinone, which we have synthesized by the Miller–Loudon–Schneider reaction. A chain of sequential transformations was used for its conversion into the target 4,11-dihydroxyanthra[2,3-b]furan-5,10-dione (furanoquinizarine): O-alkylation of the starting formylhydroxyanthraquinone with bromoacetic acid esters, cyclo-dehydration of the 3-formylanthraquinon-2-ylacetic acid esters in the presence of bases, hydrolysis of the obtained esters to 4,11-dimethoxy-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-2-carboxylic acid, its decarboxylation, and demethylation of the obtained 4,11-dimethoxyanthra[2,3-b]furan-5,10-dione.     

Oxidative cyclocondensation of cyclic thio-and selenoureas. 5. 2-Thioxothieno-and 2-thioxopyrido[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4-ones

A study was carried out on the oxidative cyclocondensation of 2-thioxothieno-and 2-thioxopyrido[2,3-d]pyrimidin-4-ones. The thiophene ring with excess π-electron density facilitates the reaction, while the pyridine ring with diminished π-electron density hinders it. 2-Thioxothieno-[2,3-d]pyridimin-4-ones were converted into previously unreported 7H,13H-[1,2,4]thiadiazolo-[3,2-b:5,4-b′]bis(thieno[2,3-d]pyridimine-7,13-diones). __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1424–1427, September, 2007.     

Condensed isoquinolines 32. Synthesis of 4H-thieno-[3′,2′:5,6]-and-[2′,3′: 5,6]pyrimido-[1,2-b]isoquinolines and 6,12-dihydro-5H-isoquino-[2,3-a]quinazoline-5,12-dione derivatives

Treatment of 2-(4-oxo-3,4-dihydrothieno[2,3-d]-and-[3,2-d]pyrimidin-2-ylmethyl)benzoic acids and 2-(4-oxo-3,4-dihydro-2-quinazolinylmethyl)benzoic acid with acetic anhydride gave thieno[3′,2′:5,6]-and-[2′,3′:5,6]pyrimido[1,2-b]isoquinoline-4,11-diones and isoquino[2,3-a]quinazoline-5,12-dione respectively. NMR spectroscopy showed that an intramolecular acylation of the above acids occurs at the atom N-1 of the pyrimidinone part of the bicycle. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1053–1061, July, 2008.     

Synthesis of Derivatives of 4,6-Dioxo-1,4,6,7,8,9-hexahydropyrimido[4,5-<Emphasis Type="Italic">b</Emphasis>][1,6]naphthyridines

It has been shown that 1-aryl-8-(4-bromophenyl)-4,6-dioxo-2H(phenyl)-7-phenyl-1,4,6,7,8,9-hexahydropyrimido[4,5-b][1,6]naphthyridines are formed on heating anilides of 1-aryl-7-(4-bromostyryl)-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidine-6-carboxylic acids in PPA.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 597–600, April, 2005.     

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.     

Synthesis of 2,3-disubstituted derivatives of pyrano-, thiopyrano-, and benzoannelated pyrido[2,3-<Emphasis Type="Italic">b</Emphasis>]thieno[3,2-<Emphasis Type="Italic">d</Emphasis>]pyrimidines

A new methods have been developed for the synthesis of condensed pyrido[2,3-b]thieno[3,2-d]pyrimidines based on cyclic derivatives of 4-cyanopyridine-3-thiones. The presence of two different reactive functional groups NH₂ and CONH gives the possibility of carrying out different conversions of thieno[2,3-b]pyridines. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, 1245–1252, August, 2008.     

Original synthesis of 2-substituted-4,11-dimethoxy-1-(phenylsulfonyl)-2,3-dihydro-1H-naphtho[2,3-f]indole-5,10-diones using TDAE and Cu-catalyzed reaction strategy

We report herein an original and rapid synthesis of 2-substituted-4,11-dimethoxy-1-(phenylsulfonyl)-2,3-dihydro-1H-naphtho[2,3-f]indole-5,10-diones by TDAE mediated synthesis of N-benzylsulfonamides followed by an intramolecular N-arylation using Cu-catalyzed system.     

Reaction of 6-amino-1,3-dimethyluracil with hexafluoroacetone and ethyl trifluoropyruvate benzoylimines

Heating of 6-amino-1,3-dimethyluracil with hexafluoroacetone and ethyl trifluoropyruvate benzoylimines in DMF in the presence of Et₃N results in 1,3-dimethyl-7-phenyl-5,5-bis(trifluoromethyl)-1,2,3,4,5,8-hexahydropyrimido[4,5-d]pyrimidine-2,4-dione and 5-benzoylamido-1,3-dimethyl-5-trifluoromethyl-1,2,3,4,5,6-hexahydropyrrolo[2,3-d]pyrimidine-2,4,6-trione, respectively.