Reaction #1135827

Reaction equation

3-(3,4-dimethoxy-phenyl)-7-hydroxy-8-methyl-chromen-4-one

acetic anhydride

→

acetic acid 3-(3,4-dimethoxy-phenyl)-8-methyl-4-oxo-4H-chromen-7-yl ester

Solvents

pyridine

Conditions

Workup

1. 1
   Temperatureheated to reflux
2. 2
   Temperatureof heating
3. 3
   Othera crystalline solid formed
4. 4
   FiltrationThe solid was filtered
5. 5
   Washrinsed with H2O (1 L)

Procedure

3-(3,4-dimethoxy-phenyl)-7-hydroxy-8-methyl-chromen-4-one (9.82 g, 31 mmol), acetic anhydride (62 ml) and pyridine (6.2 ml) were combined in a round bottom flask and heated to reflux. The reaction was cooled to room temperature after 3 hours of heating, and a crystalline solid formed. The solid was filtered and rinsed with H2O (1 L). 1H NMR in d-CDCl3 indicated pale brown crystals was acetic acid 3-(3,4-dimethoxy-phenyl)-8-methyl-4-oxo-4H-chromen-7-yl ester in 90% purity (7.214 g, 71%).

Source