Benzofuro[3,2-b]indoles

Schroeder, D. C.; Corcoran, Patrick; Holden, Claire; Mulligan, M. C.

doi:10.1021/jo01049a057

Cited by 29 publications

(12 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have found that the reaction is regioselective and gives 2-methylthieno[3,2-b]benzofuran (21) in high yield. It has been shown 3 that in the acetylation of methyl derivative 21 the substituent enters both position 3 and 6.…”

Section: Methodsmentioning

confidence: 93%

Thieno[3,2-b]benzofuran - Synthesis and Reactions

Váchal

Pihera

Svoboda

1997

Collect. Czech. Chem. Commun.

View full text Add to dashboard Cite

Thieno [3,2-b]benzofuran was synthesized starting from benzo [b]furan-3(2H)-one or benzo [b]furan-2-carbaldehyde. Electrophilic substitution reactions such as bromination, formylation, acetylation or nitration, take place in position 2. An electron donating group in position 2 directs further electrophilic substitution into positions 3 and 6, whereas compounds with an electron acceptor in position 2 are substituted exclusively in position 6. Metallation with butyllithium took place in position 2. The 1 H and 13 C NMR signals of the title compound were fully assigned.In our previous communications we discussed the synthesis 1 and reactivity 2 of a novel heterocyclic system, [1]benzothieno[3,2-b]furan (1). We observed its lower stability in acidic media, indicating an imperfect aromaticity and a weak enol ether character. Although the isomeric thieno[3,2-b]benzofuran (2) was prepared 3 , its synthesis has not been described in detail and no data on its reactivity are known. Neither compound 2 nor intermediates of its synthesis have been fully characterized by physicochemical methods. In this communication we describe novel synthetic approaches to compound 2 and discuss its reactivity in selected substitution reactions as compared with compound 1.In our search for an effective synthesis of heterocycle 2 we first tried the reaction sequence starting from benzo[b]furan-3(2H)-one (Scheme 1). This compound was converted into 3-chlorobenzo[b]furan-2-carbaldehyde (3) by the Vilsmeier-Haack formylation with N,N-dimethylformamide and phosphorus oxychloride. In contrast to the published data 3 , the nucleophilic substitution of chlorine atom with sulfanylacetic (thioglycolic) acid in an alkaline medium gave the desired [(2-formylbenzo[b]furan-3-yl)sulfanyl]acetic acid (4) only in a low yield (43%). Most probably, the starting S O O S 1 2 1468Vachal, Pihera, Svoboda:

show abstract

Section: Methodsmentioning

confidence: 93%

Thieno[3,2-b]benzofuran - Synthesis and Reactions

Váchal

Pihera

Svoboda

1997

Collect. Czech. Chem. Commun.

View full text Add to dashboard Cite

show abstract

“…59 ring closure by an intramolecular Wittig reaction [60][61][62] or o-(acyloxy)benzyl anions, 63 (c) condensation of activated methylene following Dieckmann reaction condtiions 64,65 or ketene intermediate involved cyclization, 66 (d) acid-catalyzed ring construction of a-aryloxycarbonyls 67 or (e) intramolecular Friedel-Cras reaction, 68 (f) photolytic cyclization of a-phenylketones, 69 and (g) gold(III)-catalyzed tandem reaction of O-arylhydroxylamines with 1,3-dicarbonyl substrates. 70 Moreover, a one-pot reaction for the transformation of allyl aryl ethers to 2-methylbenzofurans via sequential reaction involving Claisen rearrangement/oxidative cyclization has been reported.…”

Section: -39mentioning

confidence: 99%

Total synthesis of natural products containing benzofuran rings

et al. 2017

View full text Add to dashboard Cite

Research on natural products containing benzofuran has remarkably increased during the past few decades.Newly isolated natural products with complex structures are being studied, characterized and screened for possible biological activities. Several of such compounds have exhibited various biological activities, thus their total syntheses have attracted much attention from synthetic organic chemists. In this review, we aim to highlight the origins, structures, biological potencies, and synthetic approaches of those natural products bearing at least one benzofuran in their complex structures. Furthermore, we especially focus on the step in which this key heterocycle is installed during the total synthesis of a natural product as the desired target.

show abstract

“…Hydrolysis and decarboxylation of this ester gave 5-chlorocoumaran-3-one in good yield. Since this work was done a similar series of reactions has been described by Schroeder, Corcoran, Holden & Mulligan (1962).…”

Section: Chemical Appendixmentioning

confidence: 99%

“…Cl, 14.73%.) Schroeder et al (1962) record a melting point of 126 to 1270 C. S-Chlorocoumaran-3-one oxime. A 30% aqueous sodium hydroxide solution (540 ml.)…”

Section: Chemical Appendixmentioning

confidence: 99%

The Adrenergic‐neurone Blocking Action of Some Coumaran Compounds

Fielden¹,

Roe²,

Willey³

1964

British Journal of Pharmacology and Chemotherapy

View full text Add to dashboard Cite

Ethyldimethyl(7-methylcoumaran-3-yl)ammonium iodide (SK&F 90,109) and its guanidine analogue [N-(7-methylcoumaran-3-yl)guanidine nitrate] (SK&F 90,238) abolish the effects of adrenergic nerve stimulation in cats, as do xylocholine and bretylium. SK&F 90,109 has slight sympathomimetic actions; these are less marked than in SK&F 90,238. Large doses of SK&F 90,109 have an action, dependent on local noradrenaline stores, that delays the appearance of adrenergic-neurone blockade in conscious cats. Responses to adrenaline are, in general, enhanced by each drug, but SK&F 90,238 transiently antagonizes tachycardia induced by adrenaline and isoprenaline. Both drugs inhibit the release of noradrenaline from the spleen during splenic nerve stimulation, but the release of catechol amines from the adrenal glands, in response to electrical or chemical stimulation, is unimpaired. In contrast to the prolonged adrenergic-neurone blocking action, any inhibition of the effects of cholinergic nerve stimulation is transient. Large intravenous doses produce neuromuscular blockade. The compounds have a slight central depressant action. In contrast to reserpine and guanethidine the noradrenaline content of rat hearts is not appreciably lowered 24 hr after a single dose of either drug. Unlike xylocholine they are not local anaesthetics. Related compounds also block the effects of adrenergic-nerve stimulation. The possible modes of action of these drugs are discussed. This paper describes the actions of some coumaran (2,3-dihydrobenzofuran) derivatives on the peripheral autonomic nervous system. The preparation and properties of the compounds studied, which are derived from generic structure I, will be described later in the Chemical Appendix. It will be apparent from Fig. 1 that the structures of the two compounds whose actions are to be described in detail, namely SK&F 90,ammonium iodide] and SK&F 90,238 [N-(7-methylcoumaran-3-yl)

show abstract

Benzofuro[3,2-b]indoles

Cited by 29 publications

References 4 publications

Thieno[3,2-b]benzofuran - Synthesis and Reactions

Thieno[3,2-b]benzofuran - Synthesis and Reactions

Total synthesis of natural products containing benzofuran rings

The Adrenergic‐neurone Blocking Action of Some Coumaran Compounds

Contact Info

Product

Resources

About