Benzo[b]tellurophene, Dibenzo[b,d]tellurophene, and Their Derivatives. (Review)

Data on the synthesis, reactions, crystal structure, and spectral characteristics of benzo[b]tellurophene, dibenzo[b,d]tellurophene, and their derivatives are reviewed and analyzed.     

(苯并呋喃-2-酰基)二茂铁衍生物的合成与表征

氯乙酰基二茂铁(1)与水杨醛或取代水杨醛在聚乙二醇-400作相转移催化剂条件下,使Williamson反应与Knoevenagel反应在一锅内完成,以40.2%～70.0%的总收率得到了由羰基相连的二茂铁与苯并呋喃组成的结构新颖的闭环产物(苯并[b]呋喃-2-酰基)二茂铁衍生物2a～2n.通过IR,1HNMR,MS和元素分析确认了所合成新化合物2a～2n的结构.     

Furyl(aryl)methanes and Their Derivatives. 23. Simple Synthesis of Benzo[b]furan Derivatives from 2-Alkylfurans

New derivatives of benzo[b]furan were obtained during successive bromination and dehydrobromination of alkanones containing a gem-difurylmethyl fragment. A mechanism is proposed for the transformations that occur.     

Condensed Pyridine Bases. Synthesis and Reactions of Benzofuro[2,3-c]indeno[2,1-e]-, Benzothieno[2,3-c]Indeno[2,1-e]-, Benzofuro-[3,2-c]Indeno[2,1-e]- and Thieno[2,3:4′,5′]-thieno[3,2-c]indeno[2,1-e]pyridines

Condensation of hetarene carboxaldehydes with phthalide gave 2-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 2-(3-hydroxy-1-oxoinden-2-yl)-5-ethylthieno[2,3-b]thiophene. Starting from hetaryl acetic acids gave 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]furan and 3-(3-hydroxy-1-oxoinden-2-yl)benzo[b]thiophene. Acylation of 3-hydroxy-1-oxoinden-2-yl-substituted heterocycles using acetic anhydride in the presence of 70% HClO₄ leads to the formation of pentacyclic pyrilium salts. Pentacyclic indenopyridines are prepared by treating the pyrilium salts with ammonia. The reaction of the carbonyl group in the indenopyridines with hydroxylamine, hydrazine hydrate, and in reduction using NaBH₄ has been studied.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 435–443, March, 2005.     

New synthesis of benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f]azepines from lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one

Condensation of lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one with malonodinitrile, cyanoacetamide, and ethyl cyanoacetate gave the corresponding 2-methylidene derivatives. Their reactions with dimethylformamide diethyl acetal followed by cyclization into benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f ]azepines were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 995–1002, May, 2007.     

Reactions of 1-Substituted Benzo[4,5]imidazo[1,2-a]pyridines

Bromination of 1-oxo(imino, amino)benzo[4,5]imidazo[1,2-a]pyridines gave the corresponding 2-bromo derivatives. Acylation using the Vilsmeier complex in acetic anhydride gave the N-formyl and N-acetyl derivatives. The reaction of the amine with the Vilsmeier complex, acetyl acetone, ethyl acetoacetate, and 2,5-dimethoxytetrahydrofuran occurs at the amino group.     

Synthesis and Characteristics of Tetracyclic Systems of Benzo[b]furoindoles and Their Derivatives. (Review)

Published data on the nomenclature, structure, synthesis, and chemical characteristics of benzo[b]furoindoles with a pyrrole ring fused at various positions in relation to initial tricyclic system of dibenzofuran are reviewed.     

Synthesis and Reactions of 4-Oxiranylmethylfuro[3,2-b]pyrroles and Their Benzo Derivatives

Methyl 4-oxiranylmethyl-4H-furo[3,2-b]pyrrole-5-carboxylates 2a-c and methyl 1-oxiranylmethyl-1H-benzo[4,5]furo[3,2-b]pyrrole-2-carboxylate (2d) were prepared by reaction of the appropriate starting compounds 1a-d with excess chloromethyloxirane. The compounds 2a-d undergo oxirane ring opening by heterocyclic amines (morpholine, pyrrolidine, piperidine or 4-methylpiperazine) giving N-2-hydroxy-3-heteroaminopropyl-substituted compounds 3a-f or substituted 4,5-dihydrofuro[2',3':4,5]pyrrolo[2,1-c][1,4]oxazin-8-ones 4a-e.     

Synthesis of 3-alkyl-1,4-dihydrocyclopenta[b]indoles: unexpected formation of dimeric compounds

Acid-catalyzed dehydration of 3-alkyl(aryl)-4-methyl-1,2,3,4-tetrahydrocyclopenta[b]indol-3-ols gives dimeric derivatives of 3-alkyl(aryl)-4-methyl-1,4-dihydrocyclopenta[b]indole.     

Synthesis of hexahydroazonino[5,6-b]indoles from hexahydroazepino[4,3-b]-and-[3,4-b]indoles and activated alkynes

A reaction of substituted hexahydroazepino[4,3-b]-and-[3,4-b]indoles with activated alkynes was studied. A one-step method for the synthesis of isomeric hexahydroazonino[5,6-b]indoles different by positions of the double bond in the azonine ring was developed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2244–2250, November, 2007.     

Synthesis and biological evaluation of 5-substituted benzo[b]thiophene derivatives as anti-inflammatory agents

Abstract  5-Aminobenzo[b]thiophene-2-carboxylic acid was converted to the corresponding 5-(2-chloroacetamido)benzo[b]thiophene-2-carboxylic acid by reaction with chloroacetyl chloride. This acetamido product was treated with different alkyl, cycloalkyl, aryl, and heterocyclic amines to afford a series of C5-substituted benzo[b]thiophenes. These compounds were found to possess potent anti-inflammatory activity. Graphical abstract        

Chiral photochromic 2-(N-acyl-N-arylaminomethylene)benzo[b]thiophen-3(2H)-ones

Photochromic 2-(N-acyl-N-arylaminomethylene)benzo[b]thiophen-3(2H)-ones containing ortho-substituents in the N-phenyl ring were studied by X-ray diffraction analysis and ¹H NMR spectroscopy. It was established that these compounds have stable chiral structures due to hindered rotation of the phenyl ring around the C—N bond. The energy barrier to racemization evaluated by dynamic NMR spectroscopy is G ^# _{428 K} = 98 kJ mol^–1.     

Condensed Isoquinolines. 16. Enamine Properties of Benzo[4,5]imidazo[1,2-b]isoquinolin-11(5H)-one in Terms of Its Acylation Reactions

A study has shown that the acylation of benzo[4,5]imidazol[1,2-b]isoquinolin-11(5H)-one occurs at N₍₅₎ or at C₍₆₎ depending on the nature of the acylating reagent and the reaction conditions. It was found that principally C-acylation takes place in the absence of base. The reaction with -halo-substituted carboxylic acid chlorides leads to the formation of C-acylated products which are converted to derivatives of the novel heterocyclic system 7H-2a,6b-diazabenzo[b]cyclopenta[l,m]fluorene-1,7(2H)-dione in the presence of base.     

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[<Emphasis Type="Italic">b</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]-, -[2,3-<Emphasis Type="Italic">g</Emphasis>]-, and -[3,2-<Emphasis Type="Italic">e</Emphasis>]indoles

The Sandmeyer reaction was used to prepare 2,3-dioxo-2,3-dihydrobenzo[b]furoindoles which could be reduced with diborane or with complex hydrides to give the corresponding unsubstituted as well as the 3-hydroxybenzo[b]furoindoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1683–1689, November, 2004.     

Synthesis of Heterocycles from the Products of Anionic Arylation of Unsaturated Compounds. 7. Products of Haloarylation of Acrylic Acid and Its Esters in the Synthesis of Benzo[b]thiophene Derivatives

3-Chloro-2-chlorocarbonylbenzo[b]thiophenes were obtained on oxidation of Meerwein reaction products, viz. 3-aryl-2-halopropionic acids and their esters, with thionyl chloride in the presence of N-benzyl-N-methylmorpholinium chloride. Disubstituted thioureas were synthesized by the reaction of these compounds with ammonium thiocyanate and aromatic amines, and were cyclized by interaction with iodoacetic acid with the formation of 4-thiazolidinone derivatives. The same cyclization in the presence of aromatic aldehydes leads to the formation of the corresponding 5-arylidene-substituted 4-thiazolidinones.     

Diels-alder reaction with cyclic sulfones. 9.* Synthesis of 10-oxo-1h-tetrahydrofluo-reno[2,1-b]thiophene dioxides*2

The treatment of 5-aryl-4′,6′-dioxo-2,3,3a,4,5,6-hexahydrospiro-[benzothiophene-4,5′-1,3-dioxane] 1,1-dioxides with boron trifluoride etherate in dichloroethane leads to the formation of products of intramolecular acylation, namely, the corresponding 10-oxo-1H-5,5a,10a,10b-tetrahydrofluoreno-[2,1-b]thiophene dioxides. In all cases, 5-aryl-4-carboxyhexahydrobenzo[b]thiophene 1,1-dioxides were also isolated. The product ratio depends on the structure of the aromatic substituent at C(5) of the spiro- adducts. The structure of 4-carboxy-5-(2-methoxyphenyl)-7-methyl -2,3,3a,4,5,6-hexahydro-benzo[b]thiophene 1,1-dioxide was confirmed by X-ray diffraction structural analysis. ^*For Communication 9 see [1]. ^*2Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1503–1512, October, 2008.     

Synthesis of 3-substituted cyclopenta[b]indoles

When reacting with I₂, 2-(cyclopent-2-enyl)anilines undergo cyclization into 3-iodo-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indoles in high yields. The minor reaction products were 3,5- or 3,7-diiodoindolines. Ammonolysis of 3-iodo-5-methyl-1,2,3,3a,4,8b-hexahydro-cyclopenta[b]indole or itsN-chloroacetyl derivative results in 3-amino-5-methyl-1,2,3,3a,48b-hexahydro- and 5-methyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles. Published inIzvestiya Akademii Nauk. Seriya Khimischeskaya, No. 10, pp. 1789–1793, October, 2000.     

Tandem transformations of 10-substituted tetrahydrobenzo[b][1,6]naphthyridines resulted from the Michael addition of the nitrogen atom of the tetrahydropyridine fragment to the triple bond of activated alkynes

A reaction of 10-R-substituted tetrahydrobenzo[b][1,6]naphthyridines (R = CN, CONH₂, Me) with dimethyl acetylenedicarboxylate, methyl and ethyl propiolates, and acetylacetylene has been studied. It was found that 1-acryloyl-10-cyanotetrahydrobenzo[b][1,6]naphthyridines are the major products of the reaction of alkyl propiolates with 10-cyano-substituted naphthyridines, whereas the reaction with 10-carbamoyl-substituted naphthyridines gives a mixture of 1-acryloyl-substituted naphthyridines and hexahydrobenzo[b]pyrido[3,4,5-d,e][1,6]naphthyridines. The latter are the only products in the reaction of 10-carbamoyl-substituted naphthyridines with acetylacetylene. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1516–1527, July, 2008.     

Study of the reactions of 3-chloro-4-cyanobenzo[b][1,6]naphthyridine with nucleophilic reagents

The reactions of 3-chloro-4-cyanobenzo[b][1,6]naphthyridine (4) with S-, C-, and N-nucleophiles afford stable s-adducts at position 10. In the base-catalyzed reactions of compound 4 with thiols, the resulting -complexes are rearranged into sulfides 14a—c. Sulfides 14b,c undergo the Thorpe—Ziegler cyclization to give 1-aminobenzo[b]thieno[2,3-h][1,6]naphthyridine derivatives 15a,b. The reaction of naphthyridine 4 with aniline affords a mixture of -adducts of the C—N and C—C types, while those with aliphatic amines yield 3-amino derivatives 17a—c. In the presence of H₂O₂, benzonaphthyridine 4 adds peroxycarboxylic acids to give compounds 8a,b. In alkaline medium, adduct 8a is rearranged into 4-aminopyridine-3-carbaldehyde derivative 10.