Formation of derivatives of indole and 1-hydroxyindole upon reaction of 4-oxo-5-hydroximino-4,5,6,7-tetrahydrobenzofurazan and -tetrahydrobenzofuroxan with enamines

Upon reaction of 4-oxo-5-hydroxiinirto-4,5,6,7-tetrahydrobenzofurazan and -tetrahydrobenzofuroxan with enamines, derivatives of N-oxides of tetrahydropyrrolo[2,3-e]benzofitrazan are fonned. Upon action of acids on these compounds, we observe formation of derivatives of indole and 1-hydroxyindole, annelated with the furazan and furoxan rings.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 199–208, February, 1994. Original article submitted February 15, 1994.     

5-Benzylidene- and 5-Aminomethyl-4-oxo-4,5,6,7-tetrahydroindazoles

The reaction of 3-methyl-4-oxo-4,5,6,7-tetrahydroindazoles with benzaldehydes gave 5-benzylidene-3-methyl-4-oxo-4,5,6,7-tetrahydroindazoles. Under Mannich conditions, 3-methyl-1-phenyl-4,5,6,7-tetrahydroindazole gave 5-aminomethyl-3-methyl-4-oxo-1-phenyl-4,5,6,7-tetrahydroindazoles.     

Synthesis and mass spectrometry of 4-oxo-4,5,6,7-tetrahydroindole and 4-oxo-4,5,6,7-tetrahydrobenzofuran derivatives

We describe in this communication the synthesis and mass spectrometry of some l-aryl-2-phenyl-4-oxo-4,5,6,7-tetrahydroindole (IIIb, IVab-VIIIab, VIIIb, IXb) and 2-phenyl-4-oxo-4,5,6,7-tetrahydrobenzofuran derivatives (IIab). The fragmentations of these compounds are characterized by selectivity and the absence of any primary fragmentations involving substituents of the aryl rings. It is suggested that positive charges of the molecular ions of compounds II? IX are localized in the region of the carbonyl group and the conjugated double bond of the heterocycle.     

Reactions of 4-chloro-6-oxo-2,3-dihydro-5-azabenzofurans with amines

The reaction of 7-nitro- and 7-unsubstituted 4-chloro-6-oxo-2,3-dihydro-5-azabenzofurans with primary and secondary amines proceeds with substitution of the chlorine atoms by amine residues and with recyclization of the compounds to 5- and 7-azaindoline derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No, 10, pp. 1311–1313, October, 1973.We thank Yu. N. Sheinker, E. M. Peresleni, L. M. Alekseeva, N. A. Zosimova, and Yu. I. Pomerantsev for their assistance in conducting the spectral investigations.     

Tetracyanoethylation and fischer rearrangement of some 4-oxo-4,5,6,7-tetrahydroindoles

The reaction of the 1,2-diaryl-4-oxo-4,5,6,7-tetrahydroindoles, and 3-methyl-4-oxo-4,5,6,7-tetrahydroindole with tetracyanoethylene occurred at the 5 position of the tetrahydroindole ring. A Fischer rearrangement of the phenylhydrazones of these 4-oxotetrahydroindoles gave pyrrolo [2,3-c]carbazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 217–221, February, 1986.     

Synthesis and Structure of Ethyl 3-acetamido-4-aryl-6-methyl-2-oxo-3,4-dihydropyran-5-carboxylates

Two ethyl 3-acetamido-4-aryl-6-methyl-2-oxo-3,4-dihydropyran-5-carboxylates(3) were synthesized with high diastereoselectivities and characterized by IR,NMR and MS.The configuration of 3a was confirmed by single-crystal X-ray diffraction,ethyl 3-acetamido-4-(4-nitrophenyl)-6-methyl-2-oxo-3,4-dihydropyran-5-carboxylate(3a),C17H18N2O7.The crystal is of orthorhombic,space group Pbca with a = 11.7781(16),b = 9.5979(10),c = 32.115(3),V = 3630.4(7)3,Z = 8,Mr = 362.33,Dc = 1.326 Mg/m3,λ = 0.71073,μ(MoKα) = 0.104 mm-1,F(000) = 1520,the final R = 0.0646 and wR = 0.1464 for 1788 observed reflections with I > 2σ(I).The N-H and oxygen atom are involved in intermolecular hydrogen bonds which link the molecules into a one-dimensional chain and stabilize the structure.     

The reaction of 1,2-dioxo-1,2-dihydropyrrolo-[3,2,1-kl] phenothiazine with amines

The title compound I reacts with aliphatic amines producing ring-opened keto-amides of structure VII and with anilines forming imines of structure VIII.     

Reactions of 1-aryl- and 2,3-diaryl- 5-diazo-6,6-dimethyl-4-oxo-4,5,6,7-tetra- hydroindazoles with N-ethyl- and N-phenyl-substituted maleimides

[3+2] Cyclocondensation reactions of a series of 1,3- and 2,3-disubstituted 5-diazo-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles with N-ethyl- and N-phenyl-substituted maleimides have been used to obtain the corresponding 6,6-dimethyl-4,4',6'-trioxo-4,5,6,7-3',3'a,4',5',6',6'a-decahydrospiro-[indazole-5,3'-pyrrolo[3,4-c]pyrazoles]. On boiling these compounds in toluene nitrogen is split off and they are converted into 6',6'-dimethyl-2,4,4'-trioxo-4',5',6',7'-tetrahydro-1'H-spiro[3-azabicyclo-(3.1.0)hexane-6,5'-indazoles].     

Formation of N-substituted 4- and 7-oxo-4,5,6,7-tetrahydroindoles revisited: a mechanistic interpretation and conversion into 4- and 7-oxoindoles

An efficient method for the preparation of 4-oxo-4,5,6,7-tetrahydroindoles was successfully applied to the synthesis of N-substituted 7-oxo-4,5,6,7-tetrahydroindoles for the first time. Both isomers where converted into their corresponding 4- and 7-oxoindoles in good yields utilizing a novel aromatization protocol. Based on the impurity profile obtained, however, different mechanisms for the formation of the 4- and 7-oxo-4,5,6,7-tetrahydroindole derivatives are discussed. In addition, the reaction sequences appear to be stereospecific allowing for the direct introduction of a chiral center α to the nitrogen and preparation of enantiomerically enriched products.     

Chemistry of iminofurans. Recyclization of ethyl 2-[2-oxo-5-phenylfuran-3(2H)-ylideneamino]-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate in reaction with amines

Russian Journal of Organic Chemistry - The reaction of ethyl 2-[2-oxo-5-phenylfuran-3(2H)-ylideneamino]-4,5,6,7-tetrahydro-1-benzothiophene- 3-carboxylate with primary amines (RNH2) in toluene...     

Novel synthesis and reactions of 5,7-dialkyl-4,6-dioxo-4,5,6,7-tetrahydro- isothiazolo[3,4,-d]pyrimidine-3-carbonitriles and 6-methyl-4-oxo-4H-1-aza-5-oxa-2- thiaindene-3-carbonitrile

[reaction: see text] 5,7-Dialkyl-4,6-dioxo-4,5,6,7-tetrahydroisothiazolo[3,4-d]pyrimidine-3-carbonitriles 4, prepared from 6-amino-1,3-dialkyluracils 3 and 4,5-dichloro-5H-1,2,3-dithiazolium chloride (Appel's salt) 1, are utilized for the preparation of new derivatives of 4 bearing amino, alkylthio, amido, thioamido, tetrazolyl, and carboximidic acid ethyl ester groups at position 3. Similarly, the reactions of 6-methyl-4-oxo-4H-1-aza-5-oxa-2-thiaindene-3-carbonitrile 8, prepared from 4-amino-6-methyl-2-pyrone 6 and 1, with alkyl- and arylamines in DMF at 50 degrees C and reflux afforded different isothiazole derivatives 11 and 17, respectively. On the other hand, treatment of 8 with 1,3-diaminopropane in THF at room temperature, followed by chromatography on silica gel, gave 3-(2-oxopropyl)-6,7,8-trihydro-4H-1-thia-2,5,9-triazacyclopentacyclononene-4,10-dione 12 in 59% yield.     

Aminomethylation of substituted pyrroles and 4,5,6,7-tetrahydroindoles with biogenic cyclic amines

Aminomethylation of 2-methyl(aryl)-, 2-aryl-3-alkylpyrroles, 4,5,6,7-tetrahydroindole and its 1-vinyl- and 1-benzyl-substituted derivatives with a mixture of 5% water-ethanol solution of formaldehyde and cyclic amine (pyrrolidine, piperazine, and morpholine) without catalyst at room temperature leads to the formation of the corresponding 2-aminomethylpyrroles and 2-aminomethyl-4,5,6,7-tetrahydroindoles in up to 92% yields. In reaction of 1-vinyl-4,5,6,7-tetrahydroindole with formaldehyde water solution and piperazine in a 60% yield 1,4-bis(1-vinyl-4,5,6,7-tetrahydroindol-2-yl)piperazine was obtained, a promising bifunctional monomer and a building block for the synthesis of new indole derivatives, in particular, of biologically active polymers. In the reaction of 2-methylpyrrole and 4,5,6,7-tetrahydroindole with formaldehyde and morpholine along with the С²-aminomethylation the 1-hydroxymethylation of the pyrrole ring was observed.     

A facile, scalable preparation of 4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carbonitriles

We report a new synthesis of thieno[2,3-b]pyridine-5-carbonitriles from 2-aminothiophene-3-carboxylate esters. The key step of the synthesis is a thermally promoted elimination/decarboxylation followed by nucleophilic cyclization to give 4-oxo-4,7-dihydrothieno[2,3-b]pyridine-5-carbonitriles. The reactions proceed in good yield and generally require no chromatographic purification. These compounds are easily transformed in two steps to 4-chloro-2-iodothieno[2,3-b]pyridine-5-carbonitriles which are key intermediates in the synthesis of various kinase inhibitors.     

3,6,6-trimethyl-4-oxo-1-(2-pyridyl)-4,5,6,7-tetrahydroindazole in Schmidt reaction and Beckmann rearrangement conditions for the 4-hydroxyimino derivative

Treatment of 3,6,6-trimethyl-4-oxo-1-(2-pyridyl)-4,5,6,7-tetrahydroindazole with sodium azide in acids gives 3,7,7-trimethyl-5-oxo-1-(2-pyridyl)-5,6,7,8-tetrahydro(4H)pyrazolo[4,3-b]azepine. Heating 1-(2-pyridyl)-3,6,6-trimethyl- and 1-phenyl-6,6-dimethyl-4-hydroxyimino-4,5,6,7-tetrahydroindazoles in polyphosphoric acid gives 1-phenyl-5,6-dimethyl- and 1-(2-pyridyl)-3,5,6-trimethyl-4-aminoindazole respectively: The reactions of the latter with 4-dimethylaminobenzaldehyde gave the 4-(4-dimethylaminobenzalamino) derivative and with 2-formyldimedone the 4-(4,4-dimethyl-2,6-dioxocyclohexylidenemethylamino) derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 830–834, June, 2000.     

Efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates from the reaction of carbon disulfide and primary amines in the presence of diethyl 2-chloromalonate

An efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates via reaction of primary amines with CS₂ in the presence of diethyl 2-chloromalonate is described.     

Efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates from the reaction of carbon disulfide and primary amines in the presence of diethyl 2-chloromalonate

An efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates via reaction of primary amines with CS₂ in the presence of diethyl 2-chloromalonate is described. Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran.