Convenient Syntheses of Some Substituted 5H, 11H-Pyrano[3′,2′ : 6,7][1] benzopyrano[3,4-c]pyridines and 7,9-Dioxa-3,4,6-triazabenzo[de]naphthacenes

Hishmat, O. H.; El-Ebrashi, N. M. A.; El-Naem, Sh. E.; Rahman, A. H. Abd El

doi:10.1055/s-1982-30074

Cited by 7 publications

(6 citation statements)

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“…Орто-гідроксиформілхромони є зручними синтонами для побудови гетаренохромонів лінійної та ангулярної будови [1][2][3][4][5][6]. Реакція Даффа, що являє собою формілювання фенолів в орто-положення нагріванням з уротропіном (гексаметилентетраміном) з наступним кислотним гідролізом проміжного іміну є основним методом синтезу 7-гідрокси-8-формілхромонів [6].…”

Section: розроблено метод синтезу 7-гідрокси-6-формілхромонів на осноunclassified

“…Тому зазвичай 7-гідрокси-6-формілхромони синтезують окисненням природних лінійних фурохромонів: віснагіну і келліну (рис. 1) та їх синтетичних аналогів [1][2][3][9][10][11]. Таким чином були синтезовані похідні 7-гідрокси-6-формілхромону та флавону.…”

Section: розроблено метод синтезу 7-гідрокси-6-формілхромонів на осноunclassified

“…Сполуки з чітко вираженими оборотними окисно-відновними властивостями представляють інтерес у багатьох галузях науки і техніки. Одним із основних способів характеризації електронних властивостей є електрохімія [1][2][3], найпоширенішими методами якої є циклічна вольтаметрія, хроноамперометрія, контрольований електроліз, спектроелектрохімія та скануюча електрохімічна мікроскопія (SECM). Одним з найпотужніших інструментальних методів електрохімії є електрокристалізація, що дозволяє отримати в чистому вигляді кристали окисненої форми для подальших досліджень.…”

Section: синтез окисненої форми дитієно-ттф методом електрокристалізаціїunclassified

“…204-205°С (EtOH). Спектр ЯМР1 H, δ, м. ч. (J, Гц): 1,99 (3H, c, CН3); 5,30 (2Н, с, CH2); 6,44 (1Н, д, J = 8,8, H-5); 6,89 (3H, м, H-2', H-6', Н-4'); 7,24 (2H, д, J = 8,0, H-3', H-5'); 7,61 (1H, д, J = 8,8, H-6).…”

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Synthesis of 7-Hydroxy-2,8-Dimethyl-4-Oxo-3-Phenoxy-4h-6-Chromenecarbaldehyde

Shokol

Gorbulenko

Khilya

2018

Bull. T. Shevchenko Nat. Univ. Kyiv. Chem.

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Ortho-hydroxyformylchromones are convenient syntones for the construction of linear and angular hetarenochromones. Usually, 7-hydroxy-6-formylchromones were synthesized by oxidation of natural linear furochromones: visnagin and kellin and their synthetic analogues. The Duff reaction, which is the formylation of phenols in the ortho-position by heating with hexamethylenetetramine followed by acidic hydrolysis of intermediate imine, was also used to convert 7-hydroxychromones into 7-hydroxy-6-formylchromones, but in this case there were some difficulties because of the passivity of position 6 in 7-hydroxychromones compared to position 8 to the electrophilic attack. Thus, for the preparation of 7-hydroxy-6-formylchromones, it is necessary to use 8-substituted derivatives and to provide formylation for a long time.A method for the synthesis of 7-hydroxy-6-formylchromones based on 8-substituted 7-hydroxy-6-dialkylaminomethylchromones and hexamethylenetetramine was developed using the Duff reaction conditions. This method was demonstrated on the synthesis of 7-hydroxy-2,8-dimethyl-4-oxo-3-phenoxy-4H-6-chromenecarbaldehyde from 6-dimethylaminomethyl-7-hydroxy-2,8-dimethyl-3-phenoxy-4H-4-chromenone and hexamethylenetetramine in glacial acetic acid at reflux. It should be noted that when carrying out this reaction under heating on a water bath with subsequent hydrochloric acid hydrolysis only Mannich basehydrochloride was isolated from the reaction mixture. The starting 6-dimethylaminomethyl-7-hydroxy-2,8-dimethyl-3-phenoxy-4H-4-chromenone was synthesized from 1-(2,4-dihydroxy-3-methylphenyl)-2-phenoxyethanone in three steps. Acylation of the latter with acetic anhydride in the presence of triethylamine followed by condensation afforded 2,8-dimethyl-4-оxо-3-phenoxy-4Н-7-chromenylаcetate. Subsequent removal of acetyl protection resulted in 7-hydroxy-2,8-dimethyl-3-phenoxy-4H-4-chromenone, which on introduction into the Mannich reaction with bisdimethylaminomethane in dioxane gave rise to the desired 6-dimethylaminomethyl derivative.

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Section: розроблено метод синтезу 7-гідрокси-6-формілхромонів на осноunclassified

Section: синтез окисненої форми дитієно-ттф методом електрокристалізаціїunclassified

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Synthesis of 7-Hydroxy-2,8-Dimethyl-4-Oxo-3-Phenoxy-4h-6-Chromenecarbaldehyde

Shokol

Gorbulenko

Khilya

2018

Bull. T. Shevchenko Nat. Univ. Kyiv. Chem.

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“…The synthesis of substituted 5H-chromeno[3,4-c]pyridin-5-ones has been studied by many workers and various methods have been reported for the preparation of these compounds, including the condensation of 3-cyano-4-(2-hydroxyphenyl)pyridine derivatives in PPA or HBr/HCl [11][12][13][14], of 4-(2-fluorophenyl)nicotinic acid upon heating [15], of salicylaldehyde, malononitrile, or ethyl cyanoacetate and ketones in the presence of ammonium acetate [16][17][18][19][20][21], of 4-dicyanomethylene-4H-1-benzopyrans with amines [22], and of 3-acetylcoumarin with cyanoacetamide and ketones [23].…”

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Synthesis and properties of 4-(3-amino-2-benzofuranyl)-coumarins

Frasinyuk

Gorelov

Bondarenko

et al. 2009

Chem Heterocycl Comp

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The healing properties of many plants have been long known and their present use is continuing to increase since an advantage of plant preparations is their low toxicity and the possibility of using them for long periods without the risk of side-reactions. The major groups of therapeutically active plants are alkaloids, steroid glycosides, saponins, flavonoids, coumarins, organic acids, and vitamins.Derivatives of oxygen heterocycles are among the most common classes of natural products [1]. Compounds containing two or more oxygen heterocycles are encountered in nature much less frequently. Some of the most important such compounds are furocoumarins [2], linear and angular furochromones, coumestans, rotenoids [3], and coumarin and flavonoid derivatives containing a pyran ring fused to ring A or B [4,5].Coumarin derivatives containing a benzofuran ring possess anti-inflammatory, hypotensive, and analgesic action [6-9]. Thus, in a continuation of a study of the synthesis and properties of coumarin heteroanalogs, we investigated the preparation and reactivity of substituted 4-(3-amino-2-benzofuranyl)-coumarins. Special interest was found in the synthesis of condensed derivatives of pyridino[3,4-c]coumarins since such alkaloids have been isolated from Schumanniophyton problematicum [10]. Many alkaloids are known to be very valuable pharmaceutical products or serve as starting materials for the synthesis of such products.The alkylation of salicylonitrile by 4-bromomethylcoumarin in acetone in the presence of potassium carbonate at room temperature leads to 4-(2-cyanophenoxymethoxy)coumarins, which are converted upon heating in ethanol at reflux in the presence of potassium carbonate into 4-(3-amino-2-benzofuranyl)coumarins [9].

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