Results 201 to 210 of about 12,444 (248)

Novel fluorinated chromones

Journal of Fluorine Chemistry, 1992
Abstract We report here the autocondensation of ethyl pentafluorobenzoylacetate resulting in the formation of 3-pentafluorophenyl-1H-isopyrono [2,3-b]6,7,8,9- tetrafluorochromone ( 1 ). Hydrolysis of ( 1 ) leads to the formation of 2- pentafluorobenzoylmethyl-5,6,7,8-tetrafluorochromone ( 2 ).
V.I. Saloutin, Z.E. Skryabina, I.T. Bazyl', O.N. Chupakhin   +3 more
openaire   +1 more source

Antioxidative 2-(2-phenylethyl)chromones in Chinese eaglewood from Aquilaria sinensis

Journal of Asian natural products research, 2020
Two new compounds 6,7-dimethoxy-2-[2-(2′-hydroxyphenyl)ethyl]chromone (1) and 6,7-dimethoxy-2-[2-(4′-hydroxyphenyl)ethenyl]chromone (2), together with ten known 2-(2-phenylethyl)chromones (3–12) were isolated from the resinous wood of Aquilaria sinensis (
Chunge Li, Li Pan, Zhu-zhen Han, Yanqiao Xie, Hai-jun Hu, Xiao-Long Liu, Li-hong Wu, Li Yang, Zheng-Tao Wang   +8 more
semanticscholar   +1 more source

Synthesis of chromones

Journal of Heterocyclic Chemistry, 1979
AbstractA general procedure for the preparation of chromones from the boron difluoride complex of o‐hydroxyaryl methyl ketones is described. One of the best methods used for the preparation of chromones and benzochromones is the treatment of o‐hydroxyaryl methyl ketones with the dimethylacetal of dimethylformamide followed by treatment with sulfuric ...
G. A. Reynolds, J. A. Van Allan, A. K. Seidel   +2 more
openaire   +1 more source

Novel Chromones from Spathelia sorbifolia

Journal of Natural Products, 1987
Three new chromones, namely 10-(2',3'-dihydroxy-3'-methylbutanyl)-spatheliachromen, 10-(1',2',3'-trihydroxy-3'-methylbutanyl)spatheliachromen, and 6-(3'-hydroxy-3'-methyl-trans-but-1'-enyl)-O-methylisospatheliachrome n were isolated from the 10% aqueous MeOH extract of the twigs and leaves of Spathelia sorbifolia, together with five known chromones ...
K, Suwanborirux, C J, Chang, J M, Cassady   +2 more
openaire   +2 more sources

Toward C2-nitrogenated chromones by copper-catalyzed β-C(sp2)–H N-heteroarylation of enaminones

, 2020
The unconventionally selective β-C(sp2)–H activation of enaminones in the presence of various nitrogen nucleophiles, including azoles and cyclic amines, leading to the synthesis of 2-nitrogenated chromones has been achieved by employing a catalytic ...
Tian Luo, Jie‐Ping Wan, Yunyun Liu
semanticscholar   +1 more source

Chromone glycosides from Schumanniophyton magnificum

Phytochemistry, 1990
Two new chromone glycosides, schumanniofiosides A and B have been isolated from the root bark of Schumanniophyton magnificum and their structures shown to be 2-methyl-5,7-dihydroxychromone 5-O-beta-D-glucopyranoside and 2-methyl-5,7-dihydroxychromone 7-O-beta-D-glucopyranosyl-(1----2)-apiofuranoside, respectively.
P, Tane, J F, Ayafor, B L, Sondengam, J D, Connolly   +3 more
openaire   +2 more sources

Chromonics

Abstract The nomenclature ‘chromonic’ has been incorporated into the usual jargon of researchers to characterize lyotropic mixtures made of flat, aromatic molecules, with ionic parts on the periphery of the molecule. Differently from molecular aggregates formed by the hydrophobic/hydrophilic interactions between aliphatic molecules, as ...
Ingo Dierking, Antônio Martins Figueiredo Neto   +1 more
openaire   +1 more source

Chromon‐3‐carbaldehyde

Justus Liebigs Annalen der Chemie, 1973
AbstractAus o‐Hydroxyacetophenon (1a) wird unter Vilsmeier‐Bedingungen Chromon‐3‐carbaldehyd (3a) erhalten. Diese Reaktion ist allgemein anwendbar. – Kondensation von 3a mit tertiären aromatischen Aminen liefert die Leuko‐Verbindungen 4a und 4b, die durch Oxidation in die kationischen Farbstoffe 5a bzw. 5b übergeführt werden.
openaire   +1 more source

Two chromones from Peperomia vulcanica

Phytochemistry, 2002
TWO CHROMONES: 5-hydroxy-2-(14'-(E)-nonadecenyl) chromone (1) and 5-hydroxy-2-[12'-(3",4"-methylenedioxyphenyl)dodecanyl] chromone (2), together with six known compounds have been isolated from Peperomia vulcanica Baker & C. H. Wright (Piperaceae). Their structures were determined by spectroscopic analysis including 2D NMR techniques.
James A, Mbah, Maguerite H K, Tchuendem, Pierre, Tane, Olov, Sterner   +3 more
openaire   +2 more sources

Gold(I)-Catalyzed Hydroxy Group Assisted C(sp2)-H Alkylation of Enaminones with Diazo Compounds To Access 3-Alkyl Chromones.

Organic Letters, 2019
A strategy for expedient synthesis of 3-substituted chromones from easily available o-hydroxyarylenaminones and diazo compounds has been developed. Carefully conducted experimental and computational studies led us to propose an uncommon mechanistic ...
Pradip N. Bagle, Manoj V. Mane, Shashank P. Sancheti, Amol B Gade, Samir R. Shaikh, M. Baik, N. Patil   +6 more
semanticscholar   +1 more source