Indolobenzofurans. 1. Synthesis of isomeric indolobenzo[b]furans

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.We have previously shown [1] that 3-aminodibenzo [b,d]furan undergoes a Sandmeyer reaction to give isomeric dioxodihydro-1H-benzo[b]furoindoles. These can be used in the preparation of unsubstituted indole containing tetracyclic systems and their hydroxy derivatives with varied linking to the pyrrole ring relative to the starting tricyclic system.Using the same scheme in this work we have prepared three other isomeric dioxodihydrobenzo [b]furoindoles and studied the mechanism of their formation.2 (7) were prepared by us under Sandmeyer reaction conditions [2, 3].The 1-and 2-aminodibenzofurans (1, 2) were used in the synthesis of the heterocyclic systems indicated. The starting amines were converted to the isonitrosoacetamidodibenzofurans 3, 4, cyclization of which in the presence of sulfuric acid allowed us to prepare the corresponding dioxodihydro-1H-benzo[b]furoindoles 5-7 in 16-88% yields.The cyclizations of the 2-isonitrosoacetamidobenzofuran led to a mixture of the two isomeric linear (6) and angular (7) structures.Separation of the isomers was brought about by the successive treatment of an alkaline solution of the mixture of compounds 6 and 7, initially with acetic acid to pH 3 and, after filtration of the crystals formed, by treatment of the filtrate with conc. HCl to pH 1. The first procedure gave compound 6 (66%) and the second gave compound 7 (16%).As was expected, compound 5 was formed as a single isomer. Through a study of the properties of the indicated heterocyclic systems it was found that compounds 5-7 undergo reduction to the corresponding benzo[b]furoindoles 8-10 and the yield of the latter depends both on the nature of the reducing agent and on the reaction conditions.

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“…The melting points of the compounds 8-10 as well as their IR and UV spectra are similar to those of compounds prepared by us previously [5].…”

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confidence: 71%

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[b]furo[2,3-f]-, -[2,3-g]-, and -[3,2-e]indoles

Khoshtariya

Matnadze

Mirziashvili

et al. 2004

Chem Heterocycl Compd

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“…Fifteen Dibenzo derivatives (Figure 1) were used to evaluate the possible interaction with both the androgen receptor and 5-reductase enzyme as follows: [24] 2 = 10H-Dibenzo[a,h]anthracen-7-ylamine [25] 3 = 10H-Dibenzo[b,e]Thiopyran [26] 4 = 1n-Dibenzo[a,h]anthracen-7-yl-Butamide [27] 5 = 1n-Dibenzo[a,h]fluoren-13-one oxime [28] 6 = 1n-Dibenzo[b,d]Thiophen-2-ol [29] 7 = 1n-Dibenzo[b,d]furan-2-ol [30] 8 = 1n-Dibenzo[b,d]furan-3-amine [31] 9 = 5,11-Dihydro-6H-dibenzo[b,e]azepin-6-one [32] 10 = 5-acetyl-5H-dibenzo[b,f]azepine [33] 11 = 6-imino-6,7-dihydo-5H-dibenzo[a,c]cycloheptene-5-carbonitrile [34] 12 = 7H-Dibenzo[c,g]carbazole [35] 13 = Dibenzo[a,j]Anthracene-7,14-dione [36] 14 = Dibenzo[b,d]thiophene-4-carbaldehyde [37] 15 = Dibenzo[b,e]thiepin-11(6H)-one [38]…”

Section: Methodsmentioning

confidence: 99%

Theoretical evaluation of interaction of some dibenzo derivatives on both androgen receptor and 5α-reductase enzyme

Figueroa‐Valverde¹,

Rosas-Nexticapa²,

Alvarez-Ramirez³

et al. 2022

Clin Cancer Investig J

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There are several drugs to treat cancer; nevertheless, some can produce adverse effects, such as hypertension, hepatic injury, and erectile dysfunction. In the search for new therapeutic alternatives, some Dibenzo derivatives have been used for treating cancer; however, other data suggest that Dibenzo derivatives can increase this clinical pathology. All these data are confusing; perhaps this phenomenon is due to the different chemical structures of each Dibenzo-derivative. Analyzing this data, this research aimed to evaluate the possible interaction of some Dibenzo derivatives (compounds 1 to 15) on some biomolecules involved in prostate cancer, such as androgen receptor and 5α-reductase enzyme using flutamide, dutasteride, and finasteride drugs as theoretical tools in a Docking model. The results showed that some Dibenzo derivatives (9, 11, and 15) could interact with the androgen receptor surface. Besides, the Dibenzo derivatives 2, 5, and 13 may interact with the 5α-reductase enzyme surface. In conclusion, these data suggest that some Dibenzo derivatives could be good candidates for the treatment of prostate cancer.

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“…Compounds 2-5, 7-10, 12-15, and 17-20 were obtained according to the procedure in [3]. Ethyl Pyruvate 1-Carboxydibenzofuran-2-ylhydrazone (2).…”

Section: Methodsmentioning

confidence: 99%

A new approach to the synthesis of indole-and benzofuran-containing tetracyclic condensed systems

Khoshtariya

Kurkovskaya

Matnadze

et al. 2007

Chem Heterocycl Comp

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A new method is described for the synthesis of the 1H-benzo[b]furoindole heterocyclic systems from the corresponding isomeric amino acids with amino groups at positions 2 and 3. By this method it is possible to obtain these tetracyclic systems not only in the form of one isomer but also to convert them from one to the other. From the tetracyclic systems with angular structure it is possible to obtain the corresponding linear isomers. On the other hand, from the isomer with the linear structure it is possible to change to the isomer with angular fusion of the pyrrole ring. The classical Fischer reaction served as model for such transformations.

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Indolobenzofurans. 1. Synthesis of isomeric indolobenzo[b]furans

Cited by 4 publications

References 3 publications

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[b]furo[2,3-f]-, -[2,3-g]-, and -[3,2-e]indoles

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[b]furo[2,3-f]-, -[2,3-g]-, and -[3,2-e]indoles

Theoretical evaluation of interaction of some dibenzo derivatives on both androgen receptor and 5α-reductase enzyme

A new approach to the synthesis of indole-and benzofuran-containing tetracyclic condensed systems

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Indolobenzofurans. 1. Synthesis of isomeric indolobenzo[b]furans

Cited by 4 publications

References 3 publications

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[b]furo[2,3-f]-, -[2,3-g]-, and -[3,2-e]indoles

Synthesis and reductive reactions of 2,3-dioxo-2,3-dihydrobenzo[b]furo[2,3-f]-, -[2,3-g]-, and -[3,2-e]indoles

Theoretical evaluation of interaction of some dibenzo derivatives on both androgen receptor and 5&alpha;-reductase enzyme

A new approach to the synthesis of indole-and benzofuran-containing tetracyclic condensed systems

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Theoretical evaluation of interaction of some dibenzo derivatives on both androgen receptor and 5α-reductase enzyme