- A mild and efficient protocol for the protection of 3-hydroxychromones under phase-transfer catalysis
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A mild and efficient protocol for the introduction of different protecting groups on 3-hydroxychromones (3-HCs) under phase-transfer catalysis conditions in toluene or dichloromethane/aqueous potassium hydroxide system in the presence of crown ether has been developed. The method is useful for the protection of base-sensitive chromone derivatives. Protected chromones are easier to handle and to purify, and therefore suitable for further chemical transformations. The protecting groups were cleaved cleanly using standard conditions. Georg Thieme Verlag Stuttgart ? New York.
- Dziuba, Dmytro,Benhida, Rachid,Burger, Alain
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experimental part
p. 2159 - 2164
(2011/08/05)
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- Synthesis of novel flavone acyl esters and correlation of log P value with antioxidant and antimicrobial activity
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Three series of flavones namely 6-hydroxy flavone, 6-chloro-3-hydroxy flavone, 3,6-dihydroxy flavone were synthesized. They were further benzoylated with different aromatic acid chlorides in the presence of pyridine gave three of acyl esters series (SCF 1 to 8, SHF 1 to 8 and SDF 1 to 8). The yields of all the substituted flavones were found satisfactory. These compounds were purified, characterized by their spectral data. log P and pKa value. They were screened for in vitro radical (DPP?) scavenging activity, showed appreciable activity. 7 compounds showed antimicrobial activity against Gram-positive bacteria. Further, the MIC values of these 7 compounds were also determined. All the compounds showing antioxidant activity also showed antibacterial activity. The relationship between log P, antioxidant and antibacterial activity was established.
- Jayashree,Thejaswini,Nayak, Yogendra,Kumar, D. Vijay
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p. 1055 - 1066
(2012/03/26)
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