Some chemical properties of 2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-one and 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones

We have studied the reaction of 2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-one and 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones with amines, alkylating reagents, and hydrogen peroxide. We have shown that the presence of an aryl substituent at the 2 position of [1,3-thiazino[3,2-a]benzimidazol-4-ones has a substantial effect on the direction of the reactions. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 445–452, March, 2006.     

Synthesis of Substituted 5,6-Dihydro-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepines

A one-pot synthetic approach to the novel 5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepines by thermal cyclization of 4-acylhydrazino-2,3-dihydro-1H-1,5-benzodiazepines is described.     

A NOVEL SYNTHESIS OF 2-SUBSTITUTED-4H-THIENO [2,3-d][1,3] OXAZIN-4-ONE AND 2,3-DISUBSTITUTED THIENO [2,3-d]PYRIMIDIN-4(3H)-ONE DERIVATIVES

Abstract

The synthesis of acetic 2-{[1-methyl-2-(4-oxo-5,6,7,8-tetrahydro-4H-benzo [4,5]-thieno [2,3-d] [1,3-oxazin-2-yl)ethylidene]amino}-4,5,6,7-tetrahydrohenzo[b]thiophene ?3-carboxylic acid anhydride 5 and 2-(oxopropyl)-5,6,7,8-tetrahydro-4H-benzo-[4,5] thieno[2,3-d][1,3]oxazin-4-one 7, has been achieved in three steps from ethyl 2-amino-4,5,6,7-tetrahydrobenzo(b]thiophene-3-carboxlate 1 via the reaction with ethyl acetoacetate followed by hydrolysis and acetic anhydride-induced cyclization. The 2-substituent in compound 5 has two functional groups i.e. active methylene and acid anhydride which are suitably located for intramolecular transformation. Thermal and/or base catalyzed intramolecular cyclization of 5 afforded 2-(4-acetoxy-(hydroxyl)-2-methyl-5,6,7,8-tetrahydrobenzo[4,5] thieno[2,3-b]pyridin-3-yl)-5,6,7,8- tetrahydro-4H-benzo[4,5]thieno[2,3-d] [1,3]oxazin-4-one 10 and 9 respectively. Treatment of 5 with hydrazine hydrate, aromatic and/or heterocyclic amines induced the same intramolecular cyclization with a concomitant oxazine-pyrimidine interconversion to give 3-amino(aryl or heteryl)-2-(4-hydroxy-5,6,7,8-tetrdhydrobenzo-[4,5]thieno[2,3-b]pyridin-3-yl)-3,4,5,6,7,8-hexahydrobenzo[4,5] thieno[2,3-d] pyrimid in-4-one 11–14 respectively.     

Synthese von 4H-Pyrano[2,3-d]pyrimidinen

Summary Good yields of substituted 5-(5R-2-furyl)-4H-pyrano[2,3-d]pyrimidines4 were obtained in the reaction of 2-ethoxymethyleneamino-3-cyano-4H-pyranes2 with ammonia. Compounds2 were prepared by the condensation of the starting 2-amino-5-acetyl-3-cyano-6-methyl-4H-pyranes1 with ethyl orthoformate. Spectral properties of the bicyclic system4 in relation to compounds3 are discussed.

     

Derivatives of condensed thieno[2,3-d]-pyrimidines. 20. Synthesis of 2-substituted 5,6-dihydro-8H-pyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4(3H)-ones and 5,6,7,8-tetrahydrobenzo-[b]thieno[2,3-d]pyrimidin-4-ones

We have developed a method for obtaining 2-substituted 3-amino-6,6-dimethyl-5,6-dihydro-8H-pyrano[4′,3′:4,5]-and 5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-ones, converted by deamination to the corresponding dihydropyranothieno-3H-pyrimidinones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 441–444, March, 2006.     

Synthesis of substituted 4H-thieno[2,3-b][1]benzothiopyran-4-ones as possible schistosomicidal agents

Summary A new series of thiophenic isosters of thioxanthones, namely: 2-substituted-4H-thieno[2,3-b][1]benzothiopyran-4-ones and 5-substituted-2-nitro-8-methyl-4H-thieno[2,3-b][1]benzothiopyran-4-ones were synthesized as potential schistosomicidal agents. The synthesized compounds were characterized by their¹H-NMR data.

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Synthese von substituierten 4H-Thieno[2,3-b][1]benzothiopyran-4-onen als mögliche schistosomicide Wirkstoffe

Zusammenfassung Es wurde eine neue Serie von thiophenischen Isosteren des Thioxanthons, nämlich 2-substituierte 4H-Thieno[2,3-b][1]benzothiopyran-4-one und 5-substituierte 2-Nitro-8-methyl-4H-thieno[2,3-b][1]benzothiopyran-4-one als potentielle schistosomicide Wirkstoffe synthetisiert. Die synthetisierten Verbindungen wurden mittels ihrer¹H-NMR Daten charakterisiert.

     

Efficient Synthesis of 3,5,6,7-Tetrahydro-4H-cyclopenta[4,5] thieno[2,3-d]Pyrimidin-4-ones

The title compounds 3,5,6,7-tetrahydro-4H-cyclopenta[4,5]thieno[2,3-d]pyrimidin-4-ones（6） were synthesized by base catalytic reactions of secondary amines with carbodiimides 4, which were obtained from the aza-Wittig reaction of iminophosphoranes（3） with aromatic isocyanates.     

Investigations In the Field of 2,3'-Biquinolyl. 13. Regioselectivity in the Nitration of 2,3'-Biquinolyls and Their 1',4'-Dihydro Derivatives

The nitration of 2,3'-biquinolyls in concentrated sulfuric acid with an equivalent amount of nitric acid at room temperature takes place exclusively at the 2-quinolyl fragment with the formation of the 5- and 8-nitro derivatives or their mixtures. The nitration of the 1',4'-dihydro derivatives under these conditions leads to analogous compounds. Reduction of the nitrobiquinolyls gives the respective amines. Acylation of the latter leads to acylamino-2,3'-biquinolyls.     

Synthesis of 2-Aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones and 7-Aryl-2,3,6,7-tetrahydro-5H-imidazo[2,1-b]-1,3-thiazin-5-ones

The reaction of 2-mercaptobenzimidazole, 5-ethoxy-2-mercaptobenzimidazole, and 2-mercaptoimidazoline with cinnamoyl chloride, its derivatives, and heteroanalogs was studied. Convenient methods were found for the synthesis of 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones and 7-aryl-2,3,6,7-tetrahydro-5H-imidazo[2,1-b]-1,3-thiazin-5-ones.     

Catalyst-free synthesis of novel 4H-indeno[1,2-b]furan-4-ones and furo[2,3-d]pyrimidines in water

An operationally simple, catalyst-free, and efficient protocol for the synthesis of novel 4H-indeno[1,2-b]furan-4-one and furo[2,3-d]pyrimidine derivatives by a one-pot reaction of 2-aminopyridines, 1,3-indandione, or barbituric acid and phenylglyoxal monohydrate in water at reflux, involving domino aldol condensation, Michael addition, and ring-closing reactions is described. This transformation has several advantages, including high yield, short reaction duration, simple workup, and simple purification.     

Synthesis and Properties of Substituted Isoxazolo[3',4':4,5]thieno[2,3-b]pyridines

We synthesized derivatives of a novel heterocyclic system, isoxazolo[3',4':4,5]thieno[2,3-b]pyridine by sequential conversions in three steps: isomerization of 2-(2-R-ethylthio-2-oxo)-3-pyridyl cyanides obtained by alkylation from substituted 3-cyano-2(1H)-pyridinethiones by -halomethyl ketones in alkaline medium, to form 3-aminothieno[2,3-b]pyridines; diazotization of the amino group followed by nucleophilic substitution of the diazonium group by an azido group, bypassing the step of isolating the diazonium salts; and thermolysis of the azides formed.     

Efficient Synthesis of 3,5,6,8-Tetrahydro-4H-thiopyrano[4',3':4,5]thieno[2,3-d]pyrimidin-4-ones via an Iminophosphorane

3,5,6,8-Tetrahydro-4H-thiopyrano[4',3':4,51thieno[2,3-d]pyrimidin-4-ones(7) were synthesized via the base catalytic reactions of amines or phenols with carbodiimides(5),which were obtained from the aza-Wittig reactions of iminophosphoranes(4) with aromatic isocyanates.     

Condensed Thienopyrimidines. 14. Synthesis of 10H-Thiopyrano[4',3':4',5']thieno[2',3':4,5]pyrimido[2,3-c]-1,2,4-triazines

Reaction of a substituted 2-aminothienothiopyran with methyl(phenyl) isothiocyanate, intramolecular cyclization of the obtained N'-methyl(phenyl) thioureido derivatives, and work up of the cyclization products with hydrazine hydrate gave 2-hydrazinodihydrothiopyranothienopyrimidines. Treatment of the latter with pyruvic acid gave the novel 10H-thiopyrano[4',3':4',5']thieno[2',3':4,5]pyrimido[2,3-c]-1,2,4-triazines.     

Synthesis and self-assembly of novel calix[4]arenocrowns: formation of calix[4]areno[2]catenanes

A series of novel calix[4]arenocrowns 1a-c were efficiently synthesized by a one-pot reaction of calix[4]monohydroquinone diacetate 5 with ditosylate 6 and its analogues in the presence of sodium hydroxide. It was found that the calix[4]arenocrowns could form stable pseudorotaxane-type complexes 2a-c with paraquat, and further self-assemble into calix[4]areno[2]catenanes 3a-c with dicationic salt 8 and p-bis(bromomethyl)benzene.     

Reaction of 6-glycopyranosylaminopyrimidin-4-ones with malonic acids. Synthesis of 8-glycopyranosylpyrido[2,3-d]pyrimidin-4-one derivatives

Summary Reactions of 6-glycopyranosylaminopyrimidin-4-ones1 a–d with malonic, methyl malonic and ethyl malonic acids are discussed in this paper. These reactions have been carried out in acetic anhydride at 100°C affording the 8-glycopyranosylpyrido[2,3-d]pyrimidin-4-ones2 a–d,3 c–d and the 5-acyl-6-glycopyranosylaminopyrimidin-6-ones4 a–d,5 a–d.

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Reaktion von 6-Glycopyranosylaminopyrimidin-4-onen mit Malonsäuren. Synthese von 8-Glycopyranosylpyrido[2,3-d]pyrimidin-4-on-Dervaten

Zusammenfassung Es werden Reaktionen der 6-Glycopyranosylaminopyrimidin-4-one1 a–d mit Malonsäure, Methylmalonsäure und Ethylmalonsäure diskutiert. Die Reaktionen wurden in Essigsäureanhydrid bei 100°C ausgeführt und ergaben 8-Glycopyranosylpyrido[2,3-d]pyrimidin-4-one2 a–d,3 c–d und die 5-Acyl-6-glycopyranosylaminopyrimidin-6-one4 a–d und5 a–d.