Benzo[b]thiophene derivatives. VIII. Benzo[b]thiophene-3-earboxaldehyde and derivatives

A procedure for the preparation of benzo[b]thiophene-3-carboxaldehyde from 3-methyl-benzo[b]thiophene is reported. This aldehyde behaves as a typical reactive aromatic aldehyde with respect to oxidation, reduction, the mixed Cannizzaro reaction, reductive amination and acyloin and other condensation reactions.     

Benzo[b]thiophene. Derivatives. XXVIII. 5-bromo-3-benzo[b]thienylalanine and derivatives

A potential inhibitor of gelation of sickle hemoglobin, 5-bromo-3-benzo[b]thienylalanine, has been synthesized along with several derivatives. Several hydrolytic pathways from the intermediate ethyl 5-bromo-3-benzo[b]thienylformamidomalonate have been examined, and that involving alcoholysis to ethyl N-formyl-5-bromo-3-benzo[b]thienylalanine shown to be superior.     

Synthesis of 3-amino derivatives of benzo[b]furo[2,3-c]pyridines

The reaction of 1,7-dimethyl-3(2H)-benzo[b]furo[2,3-c]pyridone with phosphoric acid amides gave 1,7-dimethyl-3-dimethylamino (morpholino)benzo[b]furo[2,3-c]pyridines. A method for the synthesis of 3-amino derivatives of 4-nitrobenzo[b]furo[2,3-c]pyridines, which consists in heating 1,7-dimethyl-4-nitro-3(2H)-benzo[b]furo[2,3-c]pyridone with hexamethyldisilazane and secondary or primary amines in pyridine, was developed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1552–1555, November, 1991.     

Indolobenzo[b] furans. 2. Some indolo[5,6-d]- and indolo[5,4-d] benzo[b]furans

The reactivities of new heterocyclic systems, viz., indolo [5,6-d]- and indolo[5,4-d]benzo[b]furans, in several electrophilic-substitution reactions (the Mannich and Vilsmeier reactions and acylation) were studied. It was established that the indicated heterocycles, like indole, are readily formylated and aminomethylated; some anomalies are observed only in the case of acylation.See [1] for Communication 1.Translated from Kihimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 355–358, March, 1985.     

Die Schwingungsspektren der Reihe [NPCl2]3 ċ [NCCl]3

Vibrational Spectra of the Series [NPCl₂]₃ ? [NCCl]₃ The vibrational spectra of the six-membered ring systems [NPCl₂]₂[NCCl] and [NPCl₂][NCCl]₂ are reported and discussed together with the spectra of [NPCl₂]₃ and [NCCl]₃.     

Condensed heterocycles. 42. Synthesis and some properties of 3-hydroselenobenzo[b]furan-2-carbaldehyde and 2-hydroselenobenzo[b]furan-3-carbaldehyde

The reactions of 3-chlorobenzo[b]furan-2-carbaldehyde and 2-bromobenzo[b]furan-3-carbaldehyde with sodium hydrogen selenide have yielded isomeric hydroseleno aldehydes which, under the action of atmospheric oxygen, have oxidized to diselenides, while alkylation of the seleno aldehydes with methyl iodide leads to the formation of the corresponding methylseleno derivatives.For communication 41, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1177–1179, September, 1984.     

Benzo[b]thiophene derivatives. XXV. Condensation and reductive alkylation of 3-aminoalkylbenzo[b]thiophenes with formaldehyde

The reductive alkylation of 3-aminomethylbenzo[b]thiophene by the Eschweiler-Clarke (formaldehyde-formic acid) method and of 3-β-aminoethylbenzo[b]thiophene by the Borch (formaldehyde-cyanoborohydride) method proceeded in good yields. However, the Eschweiler-Clarke reaction with 3-β-aminoethylbenzo[b]thiophene gave the Pictet-Spengler cyclized product, N-methyl-1,2,3,4-tetrahydrobenzo[b]thieno[2,3c]pyridine. Mechanistic aspects of the latter reaction were investigated.     

Synthesis of 3-formylbenzo[b]furan and 1-methyl-3,4-dihydrobenzo[b]-furo[2,3-c]pyridine

Starting from the readily available 3-methylcoumarilate, 3-formylbenzo[b]furan was synthesized in high yield. The latter could be converted to 1-methyl-3,4-dihydrobenzo[b]furo-[2,3-c]pyridine in moderate yield.     

New reaction of benzo[b]thieno[3,2-b]benzo[b]thiophene disulfone

A new reaction of benzo[b]thieno[3,2-b]benzo[b]thiophene disulfone with amines that takes place with opening of one of the thiophene rings and nucleophilic substitution in the heteroaromatic ring at the site of cleavage of the S-C bond was observed. The molecular structures of the products of amination of the disulfone were determined by x-ray diffraction analysis. Hydrolysis and dehydration of the amination products gave derivatives of a new heterocyclic system, viz., benzo[b]-thieno[3,2-e]benzo[c]-1,2-oxathiin. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 320–323, March, 1980.     

Condensed heterocycles. 44. Synthesis and structure of imines of 2-mercaptobenzo[b]-furan-3-carbaldehydes and 3-mercaptobenzo[b]furan-2-carbaldehydes and their derivatives

A number of isomeric mercapto aldimines of benzo[b]furan have been obtained and their structure and properties have been studied in comparison with their benzo[b]-thiophene analogs. It has been shown that the nature of the heterocycle has no substantial influence on the structure and properties of these compounds, in contrast to the initial mercapto and hydroseleno aldehydes. It has been observed that the 2-mercapto or 2-methylthio(methylseleno) groups in benzo[b]furan-3-carbaldehydes are readily replaced by an amino group, while they are not replaced in the isomeric 3-mercapto- and 3-methylthio(methylseleno)benzo[b]furan-2-cabaldehydes.For communication 43, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 598–602, May, 1985.     

Condensed pyridine bases synthesis of some benzo[b]furo[2,3-c]-, benzo[b]- thieno[2,3-c]-, and benzo[b]selenopheno[2,3-c]-quinolines

Summary Condensation of benzo[b]furan-3(2H-one, benzo[b]thiophen-3(2H)-one and benzo[b]selenophen-3(2H)-one with dimedone gives 2-(3-heteryl)dimedones. Acylation of the latter leads to the corresponding tetracyclic pyrylium salts, from which condensed quinolines are obtained. Some condensed quinoline derivatives are obtained by reaction of 1-oxo-1,2,3,4-tetrahydroheterene[2,3-c]quinolines with sodium borohydride, hydrazine, and hydroxylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 321–326, March, 1994.     

Derivatives of 5,6-Dimethoxybenzo[b]thiophen-2-(3H)one. Synthesis of 5,6-Dimethoxybenzo[b]thieno[2,3-b]quinoline

Substituted-3-benzylidenebenzo[b]thiophen-2-ones have been synthesized. 5,6-Dimethoxybenzo[b]-thiophen-2-(3H)one with aniline and triethyl orthoformate gives the 3-anilinomethylene compound, which can be hydrolysed to give the corresponding 3-hydroxymethylene derivative. Dimethoxybenzo[b]thieno[2,3-b]-quinoline has been synthesized.     

Stereochemistry of benzo[b]quinuclidines

Diastereomerio 3-carboxybenzo[b]quinuclidines were synthesized from 3-oxobenzo[b]-quinuclidine through its cyanohydrin, 3-alkoxycarbonyl-3-hydroxy(chloro)benzo[b]quinucli-dines, and 3-hydroxymethylbenzo[b]quinuclidine. The configurations of the synthesized 3-mono- and 3,3-disubstituted benzo[b]quinuclidines were determined by means of the PMR spectra, and the stereospecificity of the reactions was followed.See [2] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 222–228, February, 1972.     

Benzo[b]thiophene derivatives. XXVI. 5-methoxy-6-chloro-3-β-acetamidoethylbenzo[b ]thiophene,a blocked analog of melatonin

A potential anti-ovulatory agent, 5-methoxy-6-chloro-3-β-acetamidoethylbenzo[b]thiophene, a sulfur analog of melatonin having the 6-position blocked to inhibit oxidative metabolism, has been synthesized from 3-hydroxy-4-chloroacetophenone.     

Indolobenzothiophenes. 2. Some electrophilic substitution reactions of indolo[6,5-d]benzo[b]thiophene

The behavior of indolo[6,5-d]benzo[b]thiophene in acylation, Mannich, Vilsmeier, and diazo coupling reactions was investigated. Acylation with acetic anhydride proceeds unambiguously at the pyrrole nitrogen atom to give 1-acetylindolo[6,5-d] benzo[b]thiophene. The products of formylation are 2- and 3-formylindolo-[6,5-d] benzo[b]thiophenes. In the case of the Mannich reaction and diazo coupling substitution takes place in the 3 position of the indolobenzo[b]thiophene ring. The structures of the products obtained were proved by spectroscopic methods.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 211–214, February, 1981.     

The synthesis of benzo[b]phenanthro[d]thiophenes and anthra[b]benzo[d]thiophenes

The synthesis of benzo[b]phenanthro[2, 3-d]thiophene ( 5 ), benzo[b]phenanthro[4, 3-d]thiophene ( 6 ), benzo-[b]phenanthro[2, 1-d]thiophene ( 9 ), benzo[b]phenanthro[3, 2-d]thiophene ( 14a ), anthra[1, 2-b]benzo[d]thiophene ( 24 ), anthra[2, 3-b]benzo[d]thiophene ( 29 ) and anthra[2, 1-b]benzo[d]thiophene ( 30 ) is described as well as the preparation of 13-methylbenzo[b]phenanthro[3, 2-d]thiophene ( 14b ).     

Synthesis of 3-aryl-5-methylpyrrolidino[1,2 b]pyrazoles

The sequential conversion of 5-hydroxy-5-methyl-4-oxo-3-arylpyrrolidino [1,2-b]pyrazoles to 5-methyl-5-chloro4-oxo-, 4-hydroxy-5-methyl-5-chloro-, and 5-methyl-4-oxo-3-arylpyrrolidino[1,2-b]pyrazoles and the HuangMinlon reduction of the last afforded 3-aryl-5-methylpyrrolidino[1,2-b]pyrazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 49–51, January, 1994.     

Condensed heteroaromatic systems including a thiophene ring. XXXII. Preparation and magnetic properties of chelates based on 2-mercapto-3-benzo[b]formylthiophene, 2-mercapto-3-iminomethylbenzo[b]thiophene,and N,N′-bis(2-mercapto-3-benzo[b]thenylidene)ethylenediamine

A convenient method was worked out for the preparation of 2-mercapto-3-benzo[b]-formylthiophene from 3-bromobenzo[b]thiophene. 2-Mercapto-3-benzo[b]formylthiophene and Schiff bases from it react readily with metal salts to give complexes. The magnetic properties of the chelates were studied, and it was found that the dependence of the magnetic susceptibility on the temperature passes through a minimum for (2-mercapto-3-benzo[b]formylthiophenato)Co and {N,N′-bis(2-mercapto-3-benzo[b]thenylidene) ethylenediaminato}cobalt. On the basis of the magnetic susceptibility data it was concluded that the chelates have planar structures.     

Mass spectrometry of pyrrolo [2, 3- b] pyrazines and pyrazino [2, 3- b]indole

The first mass spectra of pyrrolo [2, 3-b] pyrazine and some of its derivatives and of pyrazino [2, 3-b] indole are reported and compared with those of related compounds. Differences between the spectra of some aryl substituted derivatives are described and discussed.     

5α-androstano [3,2-b]pyridines, 5α-androstano[17,16-b]pyridines and androst-4 and 5-eno[17,16-b]pyridines

A new synthesis of 5α-androstano[3,2-b]pyridin-17β-ol acetate (VIa) and 17-methyl-5α-androstano[3,2-b]pyridin-17β-ol (VIb), first reported by Shimizu, Ohta, Ueno, and Takegoshi, was achieved. The analogous 5α - androstano[17,16-b]pyridin-3β-ol (XII), 5α-androstano[17,16-b]pyridin-3-one (XIVa), and androst-4-eno[17,16-b]pyridin-3-one (XIVb) were also prepared. An illustration of the method follows. Condensation of 3β-hydroxy-5α-androstan-17-one (VIIa) with 3-(2-furyl)acrolein afforded 16-[3-(2-furyl)-2-propenylidene]-3β-hydroxy-5α-androstan-17-one (VIIIa), the oxime (IXa) of which was thermally cyclized to 5α-androstano[17,16-b]-6′-(2-furyl)pyridin-3β-ol (Xa). 3β-Hydroxy-5α-androstano[17,16-b]pyridine-6′-carboxylic acid (XI) was obtained by ozonolysis of Xa. Thermal decarboxylation of XI gave XII. Cinnamaldehyde was used in place of 3-(2-furyl)acrolein to give the corresponding phenylpyridines.