Synthesis and properties of [1,4]diazepino[6,5-b]indoles

1-Aryl-2-oxo-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole N-oxides were synthesized based on 3-(N"-aryl-N"-chloroacetyl)amino-2-formylindoles. Deoxidation of 2-oxo-1-phenyl-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole N-oxide afforded 1,2,3,6-tetrahydro- and 1,2,3,4,5,6-hexahydro[1,4]diazepino[6,5-b]indole derivatives. A new approach to the synthesis of pyrido[3,2-b]indole and pyrimido[5,4-b]indole derivatives was developed.     

Synthesis of substituted thieno[2,3-b]pyrroles

A relatively simple route for synthesis of substituted thieno[2,3-b]pyrroles from readily available starting material and data for structural assignment are reported.     

Synthesis of substituted imidazo[5,1-b]benzimidazoles

Some chemical characteristics and reactions of 3-phenyl-4-methylimidazo[5,1-b]benzimidazole (I) have been examined. It has been shown that I undergoes electrophilic substitution (hydroxymethylation, acetylation, nitrosation, and the Mannich and Vilsmeier reactions), the substituent entering at the 1-position. Cyanoethylation of I gives 1-cyanoethyl-3-phenyl-4-methylimidazo[5,1-b]benzimidazole.For part III, see [3].     

Investigation of 1,2,4-triazino [6,5-b]indole-derivatives

A method was worked out for the preparation of isatin -semicarbazone, the starting material for the synthesis of 3-hydroxy-l,2,4-triazacarbazoles, and the structure of the latter was refined. Nucleophilic exchange of 3-chloro-l,2,4-triazacarbazole (which was obtained for the first time) with amines, hydrazines, and arylhydrazines was studied.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 855–857, June, 1972.     

Synthesis of substituted 4H-imidazo[5,1-b]benzimidazoles

4-Methyl-1-phenylimidazo[5,1-b]benzimidazole (III) has been synthesized. It has been shown that 1,4-dimethylimidazo[5,1-b]benzimidazole (I) and III readily undergo acetylation and nitrosation at position 3. The reaction of I and III with formalin, like the Mannich reaction, leads to the formation of methylenebis derivatives. The bromination of III with N-bromosuccinimide forms the 3-bromo derivative of III (X).For part IV, see [1].     

Synthesis of substituted imidazo[5, 1-b]benzimidazoles

By heating 2-acetylamino-1-methyl- and 1-benzyl-2-formylaminomethylbenzimidazoles with phosphorus oxychloride in toluene, 1,4-dimethyl- and 4-benzylimidazo[5, 1-b]benzimidazoles have been obtained.For part II, see [2].     

Synthesis of substituted 4H-imidazo[5,1-b]benzimidazoles VI. Some reactions of 3-phenyl-4-methylimidazo[5,1-b]benzimidazole

Several substitution reactions (the Mannich reaction, azo coupling, and bromination) of 3-phenyl-4-methylimidazo[5,1-b]benzimidazole were carried out. The corresponding 1-nitro derivative was obtained from 1-bromo-3-phenyl-4-methylimidazo[5,l-b]benzimidazole.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 396–398, March, 1972.     

Synthesis of some substituted imidazo [5, 1-b] benzothiazoles

Cyclization of formylated and acetylated -substituted 2-aminomethylbenzothiazoles with phosphorus oxychloride gives 3-substituted imidazo [5, 1-b] benzothiazoles, and 3-substituted 1-methylimidazo [5, 1-b] benzothiazoles. Treatment of 2-benzothiazolyl-4-pyridylaminomethane with formic acid gives 3-(4-pyridyl) imidazo [5, 1-b] benzothiazole. 1-Mercapto-3-phenylimidazo [5, 1-b] benzothiazole is converted into 3-phenylimidazo [5, 1-b] benzothiazole by elimination of the mercapto group.     

Synthesis of substituted 3-amino-4-cyano-1-oxo-1,2,5,10-tetrahydroazepino [3,4-b]indoles

The preparation of 3-amino- and 3-dialkylamino-4-cyanoazepino[3,4-fc]indoles bearing substituents on the aromatic nucleus and N¹⁰ is outlined. Starting from suitable substituted ethyl 3-formylindole-2-carboxy-latcs 2 , condensation with malononitrile ( 3 ) and subsequent sodium borohydride-reduction yielded ethyl 3-(2,2-dicyanoethyl)indole-2-carboxylates 5 and 19 , respectively, which were cyclized in boiling alkoxides to 3-alkoxy-4-cyanoazepino[3,4-b]indoles 10,11,20 and 21 . This sequence constitutes a novel and flexible route to functional azepino[3,4-b>]indoles. The aminolysis of 10,11,20 and 21 with different amines and ammonia yielded the title compounds which were screened for their possible biological activity.     

Synthesis of substituted 1-benzyl-2,4,6-triphenyl-2,3-dihydro-pyrazolo [3,4-b] [1,4]diazepines

The acid catalyzed condensation of 4,5-diaminopyrazoles and chalcones gave the hitherto unknown 1-benzyl-2,4,6-triphenyl-2,3-dihydropyrazolo[3,4-b][1,4]diazepines derivatives. The structure of all products was supported by ir, ¹H and ¹³C-nmr and mass spectra.     

Synthesis of substituted derivatives of imidazo [5, 1-b] benzimidazole

Heating, either molten or in high-boiling solvents, 1-methyl-2-[(N-phenylthiocarbamoyl)amino] (pyrid-4-yl)-methylbenzimidazole, or refluxing with phosphorus oxychloride in benzene acyl derivatives of 1-methyl-2-[(pyrid-4-yl)(amino)]- and 1-methyl-2 [(phenyl)(amino)]-methylbenzimidazoles, gives the corresponding derivatives of the imidazo [5, 1-b] benzimidazole system, hitherto undescribed in the literature.     

Acyl Indoles. III. The synthesis of [1,4] diazcpino [6,5-b ] indoles

The synthesis of 1,3,4,6-letrahydro-6-metliy]-2H,5H-[1,4]diazepino[6,5-b] indole-2,5-diones and 5-phenyl-3,6-dihydro[1,4]diazepino[6,5-b ]indole-2(lH)one is described. Also detailed is the, preparation of a 3-amino-2-benzoylindole.     

A new method for the synthesis of [1,4]diazepino[6,5-b]indole derivatives

Reactions of 3-[(N-aryl-N-chloroacetyl)amino]-2-formylindoles with substituted anilines gave 1,4-diaryl-2-oxo-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indol-4-ium chlorides and those with 4-aminopyridine yielded 4-amino-1-(1-aryl-2-oxo-2,5-dihydro-1H-pyrido[3,2-b]indol-3-yl)pyridinium chlorides. Reduction of 1,2,3,6-tetrahydrodiazepinoindol-4-ium chlorides afforded the corresponding hexahydro derivatives. An alternative synthesis of 1-(4-nitrophenyl)-3-oxo-4-phenyl-1,2,3,4,5,6-hexahydro[1,4]diazepino[6,5-b]indole from 3-[N-(4-nitrophenyl)amino]-2-[(phenylimino)methyl]indole was developed. The method involves the following sequence of transformations: reduction, chloroacetylation, and intramolecular alkylation. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2193–2199, December, 2006.     

Synthesis of 3-oxoisothiazolo[5,4-b] pyridines

3-Oxoisothiazolo[5,4-b]pyridines were synthesized for the first time by the reaction of 3-cyanopyridine-2-thiones or bis(3-cyanopyridyl) disulfides with concentrated sulfuric acid. It is demonstrated that 3-carbamoylpyridine-2-thiones are formed as intermediates. The 3-oxoisothiazolopyridines were converted to 3-bromoisothiazolopyridines and pyridine-2-thiones. The bromination of pyridine-2-thione was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 508–512, April, 1982.     

Synthesis of 3H[1,2]diazepino[5,6-b]indole and 3H[1,2]diazepino[4,5-b]indole derivatives

The synthesis of two new derivatives of 3H[1,2]diazepino[5,6-b]indole, 5 and 11 , and one new derivative of 3H[1,2]diazepino[4,5-b]indole, 16 , are described. Compound 5 was obtained by the reaction of methyl 2-(3-methoxycarbonyl-1-methylindole)acetate 2 , with hydrazine. Compound 11 was obtained in two ways from ethyl 2-(1-methylindole)acetate ( 8 ) by formylation and reaction with hydrazine. Compound 16 was obtained treating 3-(2-ethoxycarbonylindole)acetonitrile ( 14 ) with hydrazine.     

Synthesis and transformations of substituted 4,6-dimethylpyrazolo[3,4-b]pyridyl-3-azides and -sulfonyl chlorides

Diazotization of the amino group of 3-amino-4,6-dimethylpyrazolo[3,4-b]pyrimidines and subsequent replacement of the diazo group in the formed diazonium chlorides by an azide group gave the corresponding 3-azido derivatives. Their reactions with active methylene compounds have been studied. Substitution of the diazo group by a sulfo group gave the related 4,6-dimethylpyrazolo-[3,4-b]pyridyl-3-sulfonyl chlorides and sulfonylamides. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1556–1565, October, 2008.     

Synthesis of pyrido[3,4-b]pyrano[3,4-b]indoles

The synthesis of some pyrido[3,4-b]pyrano[3,4-b]indoles ( 3 ) from 3-hydroxy-4-(3-indolyl)piperidines ( 6 ) is reported.     

Synthesis of substituted 2-alkyl(aryl)thio-3-cyanopyridines and 3-aminothieno[2,3-b]pyridines

The alkylation of 6-methyl-4-methoxymethyl-3-cyano-2-(1H)pyridinethione by halogen derivatives in the presence of KOH proceeds regioselectively with the formation of S-alkyl derivatives. By cathodic electrolysis of the thiols in the presence of 6-methyl-4-methoxymethyl-2-chloro-3-cyanopyridine, 2-arylthiopyridines are obtained. By Thorpe-Ziegler cyclization of 2-alkylthiopyridines having an ctive methylene group, 2-aminothieno[2,3-b]pyridines have been synthesized.Kuban State Technological University, Krasnodar, 350072. N. D. Zelinskii Institute of Organic Chemistry, Moscow 117913. Southern Branch of Association Rosvuznauka, Krasnodar, 350072. Translated from Khimiya Geterotsiklicheskikh Soedinenii, NO. 10, pp. 1432–1437, October, 1996. Original article submitted April 2, 1996; revision submitted August 20, 1996.