Reaction #302847

Reaction equation

compound 3

1-(5-bromo-2-hydroxyphenyl)-3-(4-nitrophenyl)propan-1,3-dione

sulfuric acid

→

compound 4

6-bromo-4′-nitroflavone

Solvents

acetic acid

Conditions

Workup

1. 1
   Temperaturewas heated
2. 2
   Temperatureto reflux for 1 hour
3. 3
   Otherwas returned to room temperature
4. 4
   workup.ADDITIONice pieces were then added to the reaction solution
5. 5
   FiltrationThe precipitated crystal was collected by filtration

Procedure

A mixed solution consisting of compound 3 (2.00 g, 5.49 mmol), concentrated sulfuric acid (0.5 ml), and acetic acid (40 ml) was heated to reflux for 1 hour. The temperature of the resultant was returned to room temperature, and ice pieces were then added to the reaction solution. The precipitated crystal was collected by filtration, so as to obtain a product of interest, 6-bromo-4′-nitroflavone (compound 4). Yield: 1.79 g (yield constant: 94.2%) MS m/z 347 (MH+).

Source