- In vitro photoprotective evaluation and development of novel nanoemulsion with chromone derivative
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Chromone derivatives exhibiting high absorbance values in the UVA/UVB region were synthesized, and their photoprotective properties were evaluated. Chromones were prepared according to known literature procedures and characterized by high resolution mass
- Amparo, Tatiane R.,Antunes, Amanda S.,Cazati, Thiago,Diogo, Gabriela M.,Dos Santos, Viviane M. R.,Gouveia, Ana Paula,Penido, Ricardo G.,Perasoli, Fernanda B.,Sousa, Lucas R. D.,Taylor, Jason G.,Vieira, Paula M. A.,dos Santos, Orlando D. H.
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p. 1813 - 1821
(2021/08/05)
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- Rose Bengal-photosensitized oxidation of tertiary amines for the synthesis of bis-1,3-dicarbonyl compounds
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We report an example of Rose Bengal-photosensitized oxidation of tertiary amines for the synthesis of bis-1,3-dicarbonyl compounds. This protocol employs Rose Bengal as a visible-light absorbing photocatalyst without the need of a transition metal, and air as a green oxidant. Various functional groups were well tolerated to afford products with yields of up to 80% under mild reaction conditions.
- Wu, Ling-Ling,Tang, Li,Zhou, Shui-Gen,Peng, Yi-Jie,He, Xiao-Dong,Guan, Zhi,He, Yan-Hong
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p. 6471 - 6478
(2017/10/10)
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- Synthesis of multi-functionalized chromeno[2, 3-c]pyrrol-9(2H)-ones: Investigation and application of Baker-Venkataraman rearrangement involved reactions catalyzed by 4-(Dimethylamino)pyridine
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An efficient one-pot synthesis of multi-functionalized chromeno[2, 3-c]pyrrol-9(2H)-ones from 1, 3-diaryl-1, 3-diket-ones and amino acids is described. The synthesis is based on the 4-(dimethylamino)pyridine-catalyzed Baker-Venkatara-man rearrangement and
- Yu, Yanjun,Hu, Yun,Shao, Weiyan,Huang, Jianing,Zuo, Yinglin,Huo, Yingpeng,An, Linkun,Du, Jun,Bu, Xianzhang
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experimental part
p. 4551 - 4563
(2011/10/03)
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- Synthesis and reactivity of 1-aryl-9h-thieno[3,4-b]chromon-9-ones
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Methods were developed for the synthesis of 1-aryl-9H-thieno[3,4-b]chromon- 9-ones based on the reaction of bromo and dibromo derivatives of 2-methyl-4H-chromon-4-one with thioacetamide in DMF. The thienochromones were modified and their fluorescence prop
- Krayushkin, Mikhail M.,Levchenko, Konstantin S.,Yarovenko, Vladimir N.,Christoforova, Ludmila V.,Barachevsky, Valery A.,Puankov, Yury A.,Valova, Tatyana M.,Kobeleva, Olga I.,Lyssenko
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experimental part
p. 2267 - 2277
(2011/04/23)
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- Synthesis of 3-alkenyl-2-arylchromones and 2,3-dialkenylchromones via acid-catalysed retro-Michael ring opening of 3-acylchroman-4-ones
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3-Acylchromones and 3-acylflavones, readily available by acylation of 2′-hydroxydibenzoylmethane with acid anhydrides in the presence of base, undergo efficient conjugate reduction with NaBH4 in pyridine to give the corresponding chroman-4-ones/flavanones in high yields. The reduction is both regio- and chemoselective. Treatment of the chroman-4-ones with MeSO 3H generates the 3-alkenyl-2-arylchromones by a dehydrative rearrangement initiated by retro-Michael cleavage of the pyranone ring. This reduction-rearrangement sequence can be extended to 2-alkyl-3-alkenoylchromones to generate 3-alkenyl-2-styrylchromones, the first examples of 2,3-dialkenylchromones.
- Clarke, David S.,Gabbutt, Christopher D.,Hepworth, John D.,Heron, B. Mark
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p. 5515 - 5519
(2007/10/03)
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- Benzopyrans. Part 41.1 Reactions of 2-(2-dimethylaminovinyl)-lbenzopyran-4-ones with various dienophiles
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Dienamine 1 with W-phenylmaleimide and chromenone 14 as well as 15 produces, through initial [4 + 2]cycloaddition, xanthenones 10 and 18, respectively. Initial Michael addition of 1 to chromenones 14 and 16, and dimethyl acetylenedicarboxylate (DMAD), triggers the formation of xanthenone 19, 4-azaxanthenone 26 and substituted fumarate 49, respectively. Initial [2 + 2]cycloadducts of dienamines 1-3 with electrophilic acetylenes always undergo further transformations. Thus, 1 with DMAD, dibenzoylacetylene and ethyl propiolate (EP) ultimately gives xanthenones 33, 34 and 37, respectively, the latter being admixed with flavone 43. Enamine 2, cyclisable to xanthenone 11, gives 33 and 35 with DMAD, and 37 and 44 with EP. Reaction of 3 with DMAD affords 36 exclusively. The Royal Society of Chemistry 1999.
- Ghosh, Chandra Kanta,Bhattacharyya, Samita,Ghosh, Chandreyi,Patra, Amarendra
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p. 3005 - 3013
(2007/10/03)
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- Synthesis of 3-Acyl- and 3-Carbamoylflavones
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Routes to 3-acyl-, 3-carboxamido- and polyhydroxylated flavones have been devised by application of isoxazole methodology and Heck-Stille couplings.Reductive ring opening of 3-alkoxyisoxazoles gives β-keto carboxamides in contrast with 3-alkoxy-2-isoxazolines, which give β-hydroxy esters.
- Ellemose, Steen,Kure, Niels,Torsell, Kurt B. G.
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p. 524 - 529
(2007/10/02)
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- Benzopyrans: Part XXI-Reaction of 3-Acyl-4-oxo-4H-benzopyrans with Diazomethane: Synthesis of Heterocycles Fused with Benzopyran
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3-Acyl-4-oxo-4Hbenzopyrans (1, R=H and Me) react with diazomethane to afford a mixture of 3-acetyl-2-methylchromenone (3b), furochromenone (5, R as before), and pyrazole (7) whereas 3-benzoyl chromenone (1, R=Ph) yields 3-benzoyl-2-methylchromenone (3c), pyrazole (7), and the benzopyran derivatives (9) and (10).Diazomethane converts 3-acetyl-2-methylchromenone to 3-acetomethyl-2-methylchromenone.
- Ghosh, Chandra Kanta,Bhattacharyya, Atanu,Ghosh-Dastidar, Partha Pratim
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p. 128 - 130
(2007/10/02)
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