Reaktion #2142215

Reaktionsgleichung

hydrochloric acid

acetic acid

3-(2-benzyloxy-3-methoxyphenyl)-7-methoxy-4-methyl-chromen-2-one

acetic acid

hydrochloric acid

→

title product

3-(2-Hydroxy-4-methoxyphenyl)-7-hydroxy-4-methyl-chromen-2one

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeReaction monitoring by mass spectrum and thin layer chromatography
2. 2
   workup.ADDITIONwere added
3. 3
   workup.STIRRINGstirring
4. 4
   Temperaturheating
5. 5
   SonstigeThe reaction mixture was then evaporated to dryness in vacuum
6. 6
   workup.ADDITIONthe residue diluted with water
7. 7
   SonstigeThe precipitated crystalline pinkish, solid, crude title compound was isolated by filtration
8. 8
   Waschenwashed with water
9. 9
   Sonstigedried
10. 10
    SonstigeThe resulting product was triturated with ether
11. 11
    Filtrationfiltered
12. 12
    Waschenwashed with additional ether

Vorschrift

A solution of 3-(2-benzyloxy-3-methoxyphenyl)-7-methoxy-4-methyl-chromen-2-one (0.98 g, 2.44 mmol), prepared as in Example 4, in glacial acetic acid (8 mL) was treated with concentrated hydrochloric acid (3.5 mL) and the mixture stirred and heated to 60° C. for about 20 hours. Reaction monitoring by mass spectrum and thin layer chromatography revealed the presence of the starting material, so additional acetic acid (4 mL) and hydrochloric acid (3 mL) were added and stirring and heating continued for another 20 hours. The reaction mixture was then evaporated to dryness in vacuum and the residue diluted with water. The precipitated crystalline pinkish, solid, crude title compound was isolated by filtration, washed with water and dried. The resulting product was triturated with ether, filtered and washed with additional ether to yield the title product as a solid.

Quelle