Synthese von 2‐Carbonyl‐chromonen

Schmutz, J.; Hirt, R. C.; Lauener, Henri

doi:10.1002/hlca.19520350411

Cited by 48 publications

(18 citation statements)

References 5 publications

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“…Several methods of preparation of 2-formylchromones are described in the literature [3][4][5][6][7] . In our present study we made use of a modified method of Schmutz 3 .…”

Section: Resultsmentioning

confidence: 99%

Study of Substituted Formylchromones

El‐Shaaer¹,

Zahradnı́k²,

Lácová³

et al. 1994

Collect. Czech. Chem. Commun.

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Substituted derivatives of 2-and 3-formylchromone were synthesized and studied by IR, 13 C and 1 H NMR spectroscopy and the AM1 quantum chemical method. Energy and electron distribution calculations confirm the preference of the synplanar conformation in 3-formylchromones. The calculated charges on the carbon atoms correlate well with the experimental 13 C chemical shifts. Substituents bonded to the aromatic nucleus have only small effect on the electron structure of the pyrone ring.Thanks to their biological activity, chromone derivatives are the subject of considerable pharmaceutical and chemical interest 1 . In connection with prediction and preparation of biologically active compounds we synthesized some derivatives of 2-and 3-formylchromone. Whereas the derivatives of 3-formylchromone were prepared by methods described in the literature 2 , the hitherto used method of preparation of 2-formylchromones 3 was modified to give better results.Conformational analysis was performed using the AM1 quantum chemical method, the electron structure was studied by 13 C and 1 H NMR spectroscopy and the theoretical AM1 method. EXPERIMENTALThe melting points were determined on a Kofler block and are uncorrected. IR spectra were recorded in Nujol on a Specord 75 IR instrument (Zeiss, Jena) in the region 400 -4 000 cm −1 . NMR spectra were measured on an FT NMR spectrometer Bruker AM 300 at 298 K in CDCl 3 with tetramethylsilane as internal standard. The resolution in the 1 H NMR spectra was 0.12 Hz per point. Parameters of the 13 C NMR spectra (75.46 MHz) are as follows: relaxation delay 3 s, pulse width 30°, digital resolution 1.6 Hz per point. The 13 C NMR signals were assigned using a semiselective INEPT experiment, optimized to the long-range coupling constant value J = 6 Hz. Synthesis of Nitrones Ia -If. General MethodA solution of sodium ethoxide (prepared from 44 mg (2 mmol) of Na and 15 ml of ethanol) was added dropwise to a cold (−5 to 0 °C) solution of the 2-methylchromone derivative (2 mmol) andSubstituted Formylchromones

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“…Several methods of preparation of 2-formylchromones are described in the literature [3][4][5][6][7] . In our present study we made use of a modified method of Schmutz 3 .…”

Section: Resultsmentioning

confidence: 99%

Study of Substituted Formylchromones

El‐Shaaer¹,

Zahradnı́k²,

Lácová³

et al. 1994

Collect. Czech. Chem. Commun.

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“…These include Nmethyl-a- [49] and -y-picolinium iodide [50], aand ymethyl derivatives of benzothiazoles and benzoxazoles, pyrimidines and pyrazines [5 11, quinaldine, lepidine [52, 531, and 9-methylacridine [53], as well as acetylpyridines, acetone, 2,4-dinitrotoluene, phenacyl thioethers [53al, and 2-methyl-y-chromone [54].…”

Section: Ph-ch-ch -Co-chz-phmentioning

confidence: 99%

Syntheses Using Pyridinium Salts

Kröhnke

1963

Angew. Chem. Int. Ed. Engl.

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This review discusses syntheses leading to a new type of N-vinylpyridiniuin salts, to novel anionocyanines, to aminophenazines and alloxazines, as well ar to (aza-jdehydroquinolizinium, acridizinium, and morphanthridizinium salts. In addition, Mannich reactions and aminoallcylatioiis at active methylene groups of cycloimnionium SGdtS, and their reactions with amines are treated. The possibilities offered by /he "Ortoleva-King" reactioii are demonstrated using numerous exanzpks, such as a new route leading to the yohimbine skeleton.

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“…Starting from phenol or hydroquinone and succinic acid anhydride or succinic acid methylester chloride, syntheses of the two acylphenols XIII and XIV followed general methods described in the literature (18,26,29). Chromone (V) and 2-methylchromone (XII) were prepared by the methods of Hirao et al (13) and Schmutz et al (32). 2-Methylchroman-4-one (VI) was synthesized from 2-methylchromone (XII) through reduction with sodium borohydride and oxidation of the resulting 2-methylchroman-4-ol with manganese dioxide.…”

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confidence: 99%

Metabolism of Dibenzofuran by Pseudomonas sp. Strain HH69 and the Mixed Culture HH27

Fortnagel

Harms

Wittich

et al. 1990

Appl Environ Microbiol

168

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A Pseudomonas sp. strain, HH69, and a mixed culture, designated HH27, were isolated by selective enrichment from soil samples. The pure strain and the mixed culture grew aerobically on dibenzofuran as the sole source of carbon and energy. Degradation proceeded via salicylic acid which was branched into the gentisic acid and the catechol pathway. Both salicylic acid and gentisic acid accumulated in the culture medium of strain HH69. The acids were slowly metabolized after growth ceased. The enzymes responsible for their metabolism showed relatively low activities. Besides the above-mentioned acids, 2-hydroxyacetophenone, benzopyran-4-one (chromone), several 2-substituted chroman-4-ones, and traces of the four isomeric monohydroxydibenzofurans were identified in the culture medium. 2,2',3-Trihydroxybiphenyl was isolated from the medium of a dibenzofuran-converting mutant derived from parent strain HH69, which can no longer grow on dibenzofuran. This gives evidence for a novel type of dioxygenases responsible for the attack on the biarylether structure of the dibenzofuran molecule. A meta-fission mechanism for cleavage of the dihydroxylated aromatic nucleus of 2,2',3-trihydroxybiphenyl is suggested as the next enzymatic step in the degradative pathway. MATERIALS AND METHODS Media and growth conditions. A mineral salts medium was used containing (per liter): 3.5 g of Na2HPO4 2H20, 1 g of KH2PO4, 0.5 g of (NH4)2SO4, 0.1 g of MgCl2 6H20, 50 mg

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Synthese von 2‐Carbonyl‐chromonen

Abstract: Es werden drei Wege der Synthese von 2‐Carbonylchromonen beschrieben: Oxydation von 2‐Alkylchromonen mit SeO2, resp. CrO3; Spalten der Nitrone, resp. Anile von 2‐Alkylchromonen; Spalten der Isonitrosoverbindungen von 2‐Alkylchromonen.

Cited by 48 publications

References 5 publications

Study of Substituted Formylchromones

Study of Substituted Formylchromones

Syntheses Using Pyridinium Salts

Metabolism of Dibenzofuran by Pseudomonas sp. Strain HH69 and the Mixed Culture HH27

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