Bromine → 7-Bromo-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one

HRID 840368Notes

Reaction equation

HRID 840368 reaction equation
[CH3:1][CH:2]1[C:7](=[O:8])[NH:6][C:5]2[CH:9]=[CH:10][CH:11]=[CH:12][C:4]=2[O:3]1.[Br:13]Br>C(O)(=O)C>[Br:13][C:11]1[CH:10]=[CH:9][C:5]2[NH:6][C:7](=[O:8])[CH:2]([CH3:1])[O:3][C:4]=2[CH:12]=1

Participants

4

Reactant 2

HCID 24408BromineHCID 3017302-methyl-2H-1,4-benzoxazin-3(4H)-one

Product 1

HCID 226231297-Bromo-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

In 56 ml of glacial acetic acid, 6 g of 2-methyl-1,4-benzoxazin-3-(4H)-one is precooled at 0° C. and mixed drop by drop with 1.9 ml of bromine in 19 ml of glacial acetic acid. It is allowed to reach room temperature and stirred for another 8 hours. The mixture is poured onto ice water, the crystals are suctioned off and washed with water. 9.3 g of crude product results, which is recrystallized from ethanol/water. 7-Bromo-2-methyl-1,4-benzoxazin-3-(4H)-one is obtained as a by-product. As an alternative, 4-bromo-2-aminophenol can also be reacted according to the described processes.

Workup

  1. customis precooled at 0° C.
  2. customto reach room temperature
  3. additionThe mixture is poured onto ice water
  4. washwashed with water
  5. custom9.3 g of crude product results
  6. customwhich is recrystallized from ethanol/water

Sources & evidence

ORD record
ord-69d59c62c7974ca8ade48f550e266db3
Source dataset
uspto-grants-2002_04
Patent number
US06365736B1

Reaction notes

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