119892-40-9

Upstream product

• 98-88-4 benzoyl chloride 
• 103777-45-3 5-hydroxy-2,4,6-trimethoxyacetophenone 
• 100-52-7 benzaldehyde 
• 140-10-3 (E)-3-phenylacrylic acid 
• 108-95-2 phenol 
• 118-79-6 2,4,6-tribromophenol 
• 20491-92-3 2,4,6-trimethoxyphenol 
• 530-55-2 2,6-dimethoxy-p-quinone 
• 74737-06-7 3',6'-Dihydroxy-2',4'-dimethoxy-chalcon 
• 6674-40-4 5-hydroxy-7-acetoxyflavone 
• 21392-57-4 Dimethyl-chrysin 
• 1265223-29-7 4,6-dimethoxy-1aphenyl-1aH-oxireno[2,3-b]chromen-7(7aH)-one 
• 104481-00-7 1-(6-hydroxy-2,4-dimethoxy-3-methoxymethoxyphenyl)-ethanone 
• 6962-57-8 3,6-dihydroxy-2,4-dimethoxyacetophenone 

Downstream Products

• 137527-39-0 6-acetoxy-5,7-dimethoxy-2-phenyl-chromen-4-one 
• 973-67-1 5,6,7-trimethoxyflavone 
• 29550-13-8 5,6-dihydroxy-7-methoxyflavone 
• 491-67-8 5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one 
• 67047-05-6 4-oxo-2-phenyl-4H-1-benzopyran-5,6,7-triyl triacetate 
• 170234-67-0 3-Hydroxy-5,7-dimethoxy-6-methoxymethoxy-2-phenyl-chromen-4-one 
• 170234-56-7 3,6-Dihydroxy-5,7-dimethoxy-2-phenyl-chromen-4-one 
• 142646-44-4 3,5,6,7-tetrahydroxy-2-phenyl-4H-chromen-4-one 
• 170234-84-1 5,7-Dimethoxy-6-methoxymethoxy-2-phenyl-chromen-4-one 

Relevant academic research and scientific papers

Method for preparing baicalein

The invention discloses a method for preparing baicalein. According to the method, 2,6-dimethoxy-p-benzoquinone used as an initial raw material is subjected to reduction, Friedel-Crafts acetylation, claisen condensation, dehydrogenation oxidation cyclization and demethylation five reactions to obtain baicalein with high yield. The method uses low-price and easily-available initial raw material, reagent and the like, has few synthesizing steps, is easy and convenient to operate and easy for production control, has high product yield and high purity, and is suitable for large-scale preparation and production application of baicalein.

Method for preparing baicalein

The invention relates to a method for preparing anti-virus and anti-bacterial inflammatory medicine baicalein. According to the method, phenol serves as a starting material, and a key chalcone intermediate is prepared through bromination, methoxy substitution, Friedel-crafts acylation and aldol condensation; the key intermediate is subjected to oxidative cyclisation and methyl removal reaction, and high-purity baicalein can be prepared. According to the new method, adopted raw reagents are cheap and easy to obtain, the number of synthesis steps is small, reaction operation is easy and convenient, production control is easy, the product yield is high, purity is good, and the method is suitable for production and application of baicalein.

Use of acyl substituents to favour 2,3-epoxidation of 5,7-dioxygenated flavones with dimethyldioxirane

The reaction of 5,7-dimethoxyflavone with dimethyldioxirane (DMDO) gives the 2,3-epoxide rapidly at first. However, low levels of ring A hydroxylated by-products are also formed. With increasing proportions of DMDO, demethylation at C-5 becomes apparent and consumption of substrate is not matched by further significant build-up of the epoxide. Deactivation of ring A by the use of acyl groups removes this complication. 5,7-Diacylflavones give excellent yields of epoxides and monoacyl derivatives also react in good yield. Ionization potential maps derived from density functional theory calculations (B3LYP/6-31G), provide good visual indicators of the relative reactivity of the key nucleophilic loci. The epoxides may be isolated as such, or transformed into flavonols by treatment with p-toluenesulfonic acid.

Obtaining new flavanones exhibiting antifungal activities by methyltrioxorhenium-catalyzed epoxidation-methanolysis of flavones

New 3-hydroxy-2-methoxyflavanones have been obtained through epoxidation-methanolysis of the corresponding flavone with urea-hydrogen peroxide (UHP)/methyltrioxorhenium (CH3ReO3, MTO) catalytic system in methanol as nucleophilic solv

A novel route to 5,7-dimethoxy-6-hydroxyflavone

A novel route to 5,7-dimethoxy-6-hydroxyflavone is described, involving the cyclization of an intermediate phosphorane as the key step.

Studies of the selective O-alkylation and dealkylation of flavonoids. XVIII. A convenient method for synthesizing 3,5,6,7-tetrahydroxyflavones

In the demethylation of 6-hydroxy-3,4',7-trimethoxy-5-(tosyloxy)flavone with anhydrous aluminum bromide, the 5-tosyloxyl group was eliminated with bromination to give 8-bromo-3,6,7-trihydroxy-4'-methoxyflavone as the main product. When anhydrous aluminum chloride was used in the demethylation of the acetate, the 5-tosyloxyl group was cleaved prior to the demethylation to give 5,6,7-trihydroxy-3,4'-dimethoxyflavone. Demethylation of 6-hydroxy-4',5,7-trimethoxy-3-(tosyloxy)flavone and its acetate with the bromide or chloride afforded the 5,6,7-trihydroxyflavone without the cleavage of the 3-tosyloxyl group, but was not suitable for the general synthesis of the 3,5,6,7-tetrahydroxyflavones because of the difficulty in removing the protecting group. Consequently, it was found that the direct demethylation of 3,6-dihydroxy-5,7-dimethoxyflavones with anhydrous aluminum chloride-sodium iodide in acetonitrile was the most useful general method for synthesizing 3,5,6,7-tetrahydroxyflavones. Additionally, the reported structures of two natural flavones were revised.