Water → 6-(2-Bromopropanoyl)-2-methyl-2H-1,4-benzoxazin-3(4H)-one

HRID 1731321Notes

Reaction equation

HRID 1731321 reaction equation
[C:1]([C:5]1[CH:6]=[CH:7][C:8]2[O:13][CH:12]([CH3:14])[C:11](=[O:15])[NH:10][C:9]=2[CH:16]=1)(=[O:4])[CH2:2][CH3:3].[BrH:17].C(O)(=O)C.Br.[NH+]1C=CC=CC=1.O>C(O)(=O)C>[Br:17][CH:2]([CH3:3])[C:1]([C:5]1[CH:6]=[CH:7][C:8]2[O:13][CH:12]([CH3:14])[C:11](=[O:15])[NH:10][C:9]=2[CH:16]=1)=[O:4]

Participants

6

Reactant 4

HCID 962WaterHCID 21226041Pyridinium hydrobromideHCID 21893785Acetic Acid Mixture with Hydrobromic AcidHCID 22623065HCID 22623065, compound

Product 1

HCID 202286766-(2-Bromopropanoyl)-2-methyl-2H-1,4-benzoxazin-3(4H)-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a solution of 6-propionyl-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (3.4 g) and 30% hydrogen bromide-acetic acid (10 ml) in acetic acid (50 ml) was added pyridinium hydrobromide perbromide (5.12 g) at ambient temperature and the mixture was stirred for 2 hours at the same temperature. The reaction mixture was poured into water. The resultant precipitate was collected by filtration and dissolved in a mixture of ethyl acetate and tetrahydrofuran. The organic solution was washed with a saturated aqueous solution of sodium bicarbonate and brine. The solvent was dried over magnesium sulfate and removed in vacuo to afford a crystalline residue, which was washed with diisopropyl ether to give 6-(2-bromopropionyl)-2-methyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (3.8 g).

Workup

  1. filtrationThe resultant precipitate was collected by filtration
  2. dissolutiondissolved in a mixture of ethyl acetate and tetrahydrofuran
  3. washThe organic solution was washed with a saturated aqueous solution of sodium bicarbonate and brine
  4. dry with materialThe solvent was dried over magnesium sulfate
  5. customremoved in vacuo
  6. customto afford a crystalline residue, which
  7. washwas washed with diisopropyl ether

Sources & evidence

ORD record
ord-f160866186594e4bad43d98c6a23a052
Source dataset
uspto-grants-1986_11
Patent number
US04621084

Reaction notes

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