Tetra-n-butylammonium tribromide → 2-Bromo-1-[8-(tert-butyl)-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-1-ethanone

HRID 1296000Notes

Reaction equation

HRID 1296000 reaction equation
[C:1]([C:5]1[C:14]2[O:13][CH2:12][CH2:11][N:10]([CH3:15])[C:9]=2[CH:8]=[C:7]([C:16](=[O:18])[CH3:17])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].[Br-:19].[Br-].[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC.C([N+](CCCC)(CCCC)CCCC)CCC.[Br-].[Br-].[Br-].C([NH3+])CCC.C([NH3+])CCC.C([NH3+])CCC>C(O)(=O)C>[Br:19][CH2:17][C:16]([C:7]1[CH:6]=[C:5]([C:1]([CH3:4])([CH3:2])[CH3:3])[C:14]2[O:13][CH2:12][CH2:11][N:10]([CH3:15])[C:9]=2[CH:8]=1)=[O:18]

Participants

5

Reactant 3

HCID 23500184Tetra-n-butylammonium tribromideHCID 589100321-[8-(tert-Butyl)-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-1-ethanoneHCID 86601499n-Butylammonium tribromide

Product 1

HCID 589099482-Bromo-1-[8-(tert-butyl)-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-1-ethanoneYield 28.4%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of the 1-[8-(tert-butyl)-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-1-ethanone (2.61 g, 10.6 mmol) and tetra-n-butylammonium tribromide (6.62 g, 13.7 mmol) in acetic acid was stirred at room temperature for 3.5 hours under a nitrogen atmosphere, and then n-butylammonium tribromide (1.02 g, 2.12 mmol) was added and stirring was continued for 45 minutes. After distilling off the solvent under reduced pressure, ethyl acetate was added to the residue and the mixture was washed with saturated aqueous sodium hydrogencarbonate (twice) and brine in that order. It was then dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel chromatography (Wakogel-C200,80 g) and fractionated with hexane-toluene (1:3) to yield the title compound (977 mg, 28.4% yield) as bright golden yellow crystals.

Workup

  1. distillationAfter distilling off the solvent under reduced pressure, ethyl acetate
  2. additionwas added to the residue
  3. washthe mixture was washed with saturated aqueous sodium hydrogencarbonate (twice) and brine in that order
  4. dry with materialIt was then dried over anhydrous magnesium sulfate
  5. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-e9552fbae14f4c1699434585a5de05a3
Source dataset
uspto-grants-2007_07
Patent number
US07244730B2

Reaction notes

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