Reaction #78995

Reaction equation

8-fluoro-4,4-dimethyl-dihydro-benzo[d][1,3]oxazin-2-one

bromine

→

6-bromo-8-fluoro-4,4-dimethyl-dihydro-benzo[d][1,3]oxazin-2-one

Yield 84.0%

Solvents

acetic acid

acetic acid

Conditions

Workup

1. 1
   Concentrationthe mixture was concentrated
2. 2
   Otherthe residue obtained
3. 3
   Otherwas purified by a silica gel column (hexane:ethyl acetate/4:1)

Procedure

To a solution of 8-fluoro-4,4-dimethyl-dihydro-benzo[d][1,3]oxazin-2-one (0.15 g, 0.77 mmol) in acetic acid (5 mL) was added dropwise a solution of bromine (0.37 g, 2.31 mmol) in acetic acid (5 mL) under nitrogen at rt. After stirring for 10 minutes, the mixture was concentrated and the residue obtained was purified by a silica gel column (hexane:ethyl acetate/4:1) to afford 6-bromo-8-fluoro-4,4-dimethyl-dihydro-benzo[d][1,3]oxazin-2-one as an off-white solid (0.176 g, 84%) which was used in next step without further purification.

Source