3152-06-5

Upstream product

• 3353-65-9 7-hydroxy-5,6,8-trimethoxy-2-phenyl-chromen-4-one 
• 100-44-7 benzyl chloride 
• 56002-82-5 2,3-diacetoxy-1,4,5-trimethoxy-benzene 
• 176662-06-9 1-(2,4-diacetoxy-3,5,6-trimethoxyphenyl)ethanone 
• 56002-85-8 1-benzyloxy-2,3,5,6-tetramethoxybenzene 
• 176662-07-0 1-(2-Hydroxy-3,5,6-trimethoxy-4-methoxymethoxy-phenyl)-ethanone 
• 56002-84-7 2,3,5,6-tetramethoxyphenyl acetate 
• 56002-83-6 2,3,5,6-tetramethoxyphenol 
• 56002-81-4 1,2-dihydroxy-3,4,6-trimethoxybenzene 

Downstream Products

• 176662-12-7 7-Benzyloxy-3-hydroxy-5,6,8-trimethoxy-2-phenyl-chromen-4-one 
• 176662-17-2 Toluene-4-sulfonic acid 7-benzyloxy-5,6,8-trimethoxy-4-oxo-2-phenyl-4H-chromen-3-yl ester 
• 176662-23-0 Toluene-4-sulfonic acid 7-benzyloxy-5-hydroxy-6,8-dimethoxy-4-oxo-2-phenyl-4H-chromen-3-yl ester 
• 176662-20-7 7-Benzyloxy-3,5,6,8-tetramethoxy-2-phenyl-chromen-4-one 
• 176662-32-1 7-Benzyloxy-5-hydroxy-3,6,8-trimethoxy-2-phenyl-chromen-4-one 
• 176662-26-3 7-Benzyloxy-3,5-dihydroxy-6,8-dimethoxy-2-phenyl-chromen-4-one 
• 71479-92-0 5,7-dihydroxy-3,6,8-trimethoxyflavone 
• 33183-51-6 3,5,7-trihydroxy-6,8-dimethoxy-2-phenyl-chromen-4-one 

Relevant academic research and scientific papers

Studies of the Selective O-Alkylation and Dealkylation of Flavonoids. XXI.: A Convenient Method for Synthesizing 3,5,7-Trihydroxy-6,8-dimethoxyflavones and 5,7-Dihydroxy-3,6,8-trimethoxyflavones

The Friedel-Crafts acetylation with boron trifluoride was studied and it was found that 1-(2,4-dihydroxy-3,5,6-trimethoxyphenyl)ethanone was conveniently synthesized from 2,3,5,6-tetramethoxyphenyl acetate in a mixture of acetic anhydride and acetic acid. 1-[2-Hydroxy-3,5,6-trimethoxy-4-(methoxyinethoxy)phenyl]ethanone was cyclized to 7-hydroxy-5,6,8-trimethoxyflavone by using the Baker-Venkataraman transformation. The 7-benzyl ether of the flavone was oxidized with dimethyldioxirane and then treated with a small amount of p-toluenesulfonic acid to give 7-benzyloxy-3-hydroxy-5,6,8-trimethoxyflavone, which was converted into the methyl ether and tosylate. The 5-methoxy group in the methyl ether or tosylate was selectively cleaved with anhydrous aluminum bromide in acetonitrile under mild conditions to give the corresponding 5-hydroxyflavones and the latter compound with a 3-tosyloxy group was smoothly converted into the 3,5-dihydroxyflavone by hydrolysis with potassium carbonate in methanol. The hydrogenolysis of the 7-benzyloxy-3,5-dihydroxyflavone and its 3-methyl ether afforded quantitatively 3,5,7-trihydroxy-6,8-dimethoxyflavone and its 3-methyl ether. The process was suitable as a general method for synthesizing 3,5,7-trihydroxy-6,8-dimethoxyflavones and their 3-methyl ethers and the six flavones were synthesized for the clarification of their 1H and 13CNMR, MS, and UV spectral properties.