Synthesis of new pyridazino[4′,3′:4,5]-thieno[3,2-d]-1,2,3-triazine and pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazine derivatives

Summary 8,9-Diphenylpyridazino[4,3:4,5]thieno[3,2-d]-1,2,3-triazin-4(3H)-one (2), 3-substituted 8,9-diphenylpyridazino[4,3:4,5]thieno[3,2-d]-1,2,3-triazin-4(3H)-ones (3a–c), 3,4-diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazin-8(7H)-one (4), 8-chloro-3,4-diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazine (5), 8-substituted 3,4-diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazines (6a–h) and 7-substituted 3,4-diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazin-8(7H)-ones(7a–c) were synthesized from 5-amino-3,4-diphenylthieno[2,3-c]pyridazine-6-carboxamide (1).

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Synthese neuer Pyridazino[4,3:4,5]thieno[3,2-d]-1,2,3-triazin-und Pyrimido[4,5:4,5]thieno[2,3-c]pyridazin-Derivate

Zusammenfassung Folgende Verbindungen wurden ausgehend von 5-Amino-3,4-diphenylthieno[2,3-c]pyridazin-6-carboxamid (1) synthetisiert: 8,9-Diphenylpyridazino[4,3:4,5]thieno[3,2-d]-1,2,3-triazin-4(3H)-on (2), 3-substituierte 8,9-Diphenylpyridazino[4,3:4,5]thieno[3,2-d]-1,2,3-triazin-4(3H)-one (3a–c), 3,4-Diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazin-8[7H]-on (4), 8-Chlor-3,4-diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazin (5), 8-substituierte 3,4-Diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazine (6a–h) und 7-substituierte 3,4-Diphenylpyrimido[4,5:4,5]thieno[2,3-c]pyridazin-8(7H)-one (7a–c).

     

Pyridazines,LIV: On the synthesis of pyridazine-fused S-heterocycles: Thieno[2,3-c]pyridazine,pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazine,and pyridazino[3,4-b][1,4]benzothiazine

Summary Starting from 3-chloro-4-pyridazinecarbonitrile (1), the thienopyridazine derivatives2 and3 were prepared. Condensation of3 with triethyl orthoformate afforded the novel tricyclic system4. Reaction of1 with 2-aminothiophenol, followed by treatment with NaH/DMSO was found to give the diaza-phenothiazine6 instead of the expected condensed thiazepine.Dedicated with best wishes to Prof. Dr. G. Zigeuner on the occasion of his 70^th anniversary     

Synthesis of derivatives of the new heterocyclic system pyrimido[4′,5′:4,5]pyrimido[1,2-a]benzimidazole

3-Phenyl-5-methyl(phenyl)-1H,3H-pyrimido[4,5:4,5]pyrimido[1,2-a]benzimi-dazole-2,4-diones were obtained by the cyclization of N-phenyl-N-[3-ethoxycar-bonyl-4-methyl(phenyl)pyrimido [1,2-a]benzimidazol-2-yl]ureas by the action of potassium carbonate. 2-Methyl-5-phenyl-1H-pyrimido[4,5:4,5]pyrimido[1,2-a]benzimidazol-4-one was obtained by the reaction of N-3-ethoxycarbonyl-4-phenylpyrimido[1,2-a]benzimidazol-2-yl]-N,N-dimethylacetamidine with ammonium acetate in ethanol. The synthesized compounds are members of a new heterocyclic system. The molecular and crystal structure of the solvate of 3-phenyl-5-methyl-1H,3H-pyrimido[4,5:4,5] pyrimido[1,2-a]benzimidazole-2,4-dione with two molecules of DMF was studied by x-ray crystallographic analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2587–2592, November, 1991.     

Synthesis of pyrido[3′,2′:4,5]thieno[2,3-c]cinnolines — A new heterocyclic system

Pyrido[3,2:4,5]thieno[2,3-c]cinnolines, new heterocyclic compounds, were obtained in three steps: 1) alkylation of 3-cyanopyridine-2(1H)-thiones by o-nitrobenzyl bromide to give 2-(o-nitrobenzyl)thio-3-cyanopyridines, 2) closure of the thiophene ring in these intermediates to give 3-amino-2-(o-nitrophenyl)thieno[2,3-b]pyridines, and 3) closure of the pyridazine ring by condensation of the amino and nitro groups in triethyl phosphite, leading to the final heterocyclic system.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 104–109, January, 1998.     

A Convenient Synthesis of Novel Functionalized Pyrimido[5′,4′:4,5]thieno[3,2-c]pyridazines and Related Fused Systems

Possible approaches to the synthesis of functionalized, pyrimido[5′,4′:4,5]thieno [3,2-c]pyridazines 2-18 , pyridazino[3′,4′:4,5]thieno[2,3-d]triazines 19, 20a,b and pyrido[3′,2′:4,5]thieno[3,2-c]pyridazines 22a,b are described. The sequence involves the heterocyclization of 6-amino-1,3-diphenyl-1,4-dihydrothieno[3,2-c]pyridazine-7-carboxamide (1) with appropriate reagents. The antimicrobial activity of some the newly synthesized compounds was examined. All tested compounds proved to be active as antibacterial and antifungal agents.     

Pyridazine Derivatives and Related Compounds. Part 11: 1Synthesis of Some Pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazines

3-Substituted pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazine-2,4-di-ones and 3-amino-2-methylpyrimido[4′,5′:4,5]thieno[2,3-c]pyridazine-4-ones were synthesized starting from ethyl 5-aminothieno[2,3-c] pyridazine-6-carboxylate 1. Reaction of amino ester 1with phenyl isothiocyanate affords thiourea derivative 10which undergo further transformation to the related fused heterocyclic systems.     

Synthesis and antitumor evaluation of novel tetrahydrobenzo[4′,5′]thieno[3′,2′:5,6]pyrimido[1,2-b]isoquinoline derivatives

In the present study, a novel 8,9,10,11-tetrahydro-7H,14H-benzo[4′,5′] thieno[2′,3′:4,5]-1,3-oxazino[3,2-b]isoquinoline-7,14-dione 5 was prepared by condensation of 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzothiophene with homophthalic anhydride under microwave irradiation, followed by alkaline hydrolysis and cyclization using acetyl chloride. Compound 5 was further allowed to react with different nitrogen nucleophiles to get new tetrahydrobenzothienopyrimido isoquinolinone derivatives. The structures of the prepared compounds were elucidated by IR, ¹H-NMR, ¹³C-NMR, and mass spectroscopy. The newly prepared compounds were tested in vitro against a panel of two human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, and mammary gland breast MCF-7. Almost all the tested compounds showed satisfactory activity.     

Alkylation of pyrimido[5′,4′:5,6]pyrido[3,2-b]indol-4-one derivatives

Alkylation of 11-benzyl-3,11-dihydro-4H-pyrimido[5′,4′:5,6]pyrido[3,2-b]indol-4-one with methyl iodide and methyl bromoacetate in DMF gave 3-alkylpyrimidopyridoindolones as the corresponding salts. The reaction in acetone in the presence of K₂CO₃ yielded 3,6-disubstitution products. Alkylation with DMF dimethyl acetal gave a mixture of the 3- and 6-alkylpyrimidopyridoindol-4-one bases. The structure of 4-oxo-4,6-dihydro-3H-pyrimido-[5′,4′:5,6]pyrido[3,2-b]indol-11-ium chloride (3b) was proved by X-ray diffraction analysis.     

Synthesis of 2,4-disubstituted pyrimido[4,5-b]-indoles,pyrano[4′,3′:4,5]pyrrolo[2,3-d]pyrimidines and some conversions of pyrimido[4,5-d]indoles

Methods have been developed for the production of 2,4-disubstituted 5,6,7,8-tetrahydro-9H-pyrimido[4,5-b]indoles and pyrano[43:4,5]pyrrolo[2,3-d]pyrimidines. Heterocyclization reactions were carried out on 4-hydrazinopyrimido[4,5-b]indoles.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan, 375014. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10. pp. 1413–1416, October, 1996. Original article submitted June 21, 1996.     

Microwave-assisted synthesis of new pyrimido[4′,5′:4,5]thiazolo[3,2-a]benzimidazol-4(3H)-one derivatives in solvent-free condition

Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′:4,5]thiazolo[3,2-α]benzimidazol-4(3H)-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-carboxamide and aroyl halides in solvent-free condition is described.In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.     

Synthesis of pyrido[3′,2′:4,5]thieno[2,3-e][1,2,4]triazolo[4,3-a]pyrimidin-5(4H)-one derivatives

Some new pyrido[3′,2′:4,5]thieno[2,3-e]-[1,2,4]triazolo[4,3-a] pyrimidin-5(4H)-ones were prepared through heterocyclization of ethyl 3-aminothieno[2,3-b]pyridine-2-carboxylate with phenyl or ethyl isothiocyanate followed by nucleophilic displacement with hydrazine, and finally cyclocondensation with orthoesters. Correspondence: Abolghasem Davoodnia, Department of Chemistry, School of Sciences, Islamic Azad University, Mashhad Branch, Mashhad 91735-413, Iran.     

New convenient synthesis of substituted 6,9-dihydropyrido[3′,2′:4,5]thieno[3,2-b]pyridines and 6,9-dihydropyrido[3′,2′:4,5]thieno[3,2-d]pyrimidines

1,4-Dihydro-3-cyano-2-pyridinethiolates react with 2-bromo-l-(4-bromophenyl)ethylidenemalononitrile or N-cyanochloracetanudine to give 6, 9-dihydropyrido[3, 2': 4, 5]thieno[3. 2-b]pyridines or 6, 9-dihydropyrido-[3.2:4.5Jthieno(3,2-d]pyrimidines, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 553–556, April, 1996.     

Synthesis of Some New Thieno[2,3-b]pyridines,Pyrimidino[4′,5′:4,5]thieno[2,3-b]-pyridines,and 2,3-Dihydro-1,3,4-thiadiazoles

Thieno[2,3-b]pyridines were synthesized from 6-benzofuran-2-yl-4-phenyl-2-sulfanylpyridine-3-carbonitrile and each of chloro acetone, ethyl chloroacetate, ω -bromoacetophenone, and chloroacetonitrile. These compounds were conveniently converted into novel pyrido[4′,5′:4,5]thieno[3,2-d]pyrimidines. Also, 2,3-dihydro-1,3,4-thiadiazole was synthesized from hydrazonoyl halides and 2-benzofuran-2-yl-3-(phenylamino)-3-thioxopropanenitrile. The structures of the products have been elucidated by elemental analyses, spectral data studies, and alternative syntheses whenever possible. The newly synthesized compounds were tested towards microorganisms.     

Synthesis of derivatives of pyrido[3′,2′:4,5]furo[3,2-c]isoquinoline heterocyclic system

An approach to the synthesis of derivatives of new heterocyclic system, pyrido[3′,2′:4,5]-furo[3,2-c]isoquinoline, was suggested. A condensation reaction of substituted 3-cyanopyridin-2(1H)-ones with methyl 2-(chloromethyl)benzoate and subsequent treatment of the condensation product with potassium tert-butoxide leads to substituted pyrido[3′,2′:4,5]furo[3,2-c]-isoquinolin-5(6H)-ones. Similarly, a condensation reaction of substituted 3-cyanopyridin-2(1H)-ones with 2-(chloromethyl)benzonitrile and subsequent treatment of the condensation product with potassium tert-butoxide gives substituted 5-aminopyrido[3′,2′:4,5]furo[3,2-c]-isoquinolines.     

A novel three-component method for the synthesis of spiro[chromeno [4′,3′:4,5] pyrimido[1,2-b] indazole-7,3′-indoline]-2′,6(9H)-dione

A green, efficient, and rapid procedure for the synthesis of novel spiro[chromeno[4′,3′:4,5] pyrimido[1,2-b]indazole-7,3′-indoline]-2′,6(9 H)-dione derivatives has been developed by one-pot condensation of 4-hydroxy-2H-chromen-2-one, isatin, and 1H-indazole-3-amine, in the presence of acetic acid in EtOH. This method has the advantages of operational simplicity, and high yield of products via a simple experimental and work-up procedure as compared to the conventional methods. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.     

Selective synthesis and optical properties of diimidazo[1,2-a:5′,1′-c]quinoxaline derivatives

Novel diimidazo[1,2-a:5′,1′-c]quinoxaline derivatives were synthesized by a Pd-catalyzed intramolecular coupling reaction of 1,2-bis(2-iodo-1H-imidazol-1-yl)benzene. This method was applied to the selective introduction of an aryl substituent at the 10 position by the addition of a boronic ester. Moreover, a stepwise introduction of the aryl substituent could be achieved by the further coupling reaction at the 3 position. Focused on the optical properties, a more efficient substituent effect at the 10 position was obtained compared with the analogous structure, diimidazo[1,2-a:2′,1′-c]quinoxaline derivatives. In addition, we revealed that the diimidazo[1,2-a:5′,1′-c]quinoxaline skeleton potentially has an electron-donating character on the optical properties by introducing an electron-withdrawing substituent.     

Microwave-assisted synthesis of new pyrimido[4′,5′：4,5]thiazolo[3,2-α] benzimidazol-4（3H）-one derivatives in solvent-free condition

Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′：4,5]thiazolo[3,2-α]benzimidazol-4（3H）-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.     

Efficient Synthesis and Fungicidal Activities of 3,5,6,8-Tetrahydro-4H-thiopyrano[4′,3′ :4,5]thieno[2,3-d]pyrimidin-4-ones

The carbodiimides 4, obtained from reactions of iminophosphorane 3 with aromatic isocyanates, reacted with amines, phenols, or ROH to give 2-substituted 3,5,6,8-tetrahydro-4H-thiopyrano[4′,3′ :4,5]thieno [2,3-d]pyrimidin-4-ones 6 in the presence of a catalytic amount of sodium alkoxide or solid potassium carbonate in satisfactory yields. Compounds 6 exhibited fungicidal activity. For example, compounds 6e, 6m, and 6s showed 70% inhibition activities against Dothiorella gregaria in 100 mg/L.     

Synthesis of 3-Substituted Pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines and Related Fused Thiazolo Derivatives

New ethyl 3-(substituted)-4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4',3':4,5]thieno-[2,3-d]pyrimidine-7-carboxylates ( 3a , b ), ( 6 ),( 11-13 ), ethyl 3-methyl-5-oxo-2,3,6,9-tetrahydro 5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidine-8(7H)-carboxylate ( 4 ), and ethyl 2-methyl-5-oxo-2,3,6,9-tetrahydro-5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]-pyrimidine-8(7H)-carboxylate ( 8 ) have been synthesized from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1. The structure of these compounds as well as their intermediates have been established by their spectral data.