5,5-Dibromobarbituric acid → 2-Bromo-1-(3-methylisoxazol-5-yl)ethanone

HRID 724915Notes

Reaction equation

HRID 724915 reaction equation
[C:1]([C:4]1[O:8][N:7]=[C:6]([CH3:9])[CH:5]=1)(=[O:3])[CH3:2].[Br:10]C1(Br)C(=O)NC(=O)NC1=O>C1COCC1>[Br:10][CH2:2][C:1]([C:4]1[O:8][N:7]=[C:6]([CH3:9])[CH:5]=1)=[O:3]

Participants

4

Reactant 2

HCID 948775,5-Dibromobarbituric acidHCID 130013941-(3-Methyl-1,2-oxazol-5-yl)ethan-1-one

Product 1

HCID 148146892-Bromo-1-(3-methylisoxazol-5-yl)ethanoneYield 68.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 0.43 g (3.43 mmol) of 5-acetyl-3-methylisoxazole (for synthesis see S. Chimichi, B. Cosimelli, Synth. Comm. 1992, 22, 2909-2920) in 10 mL of THF was added to a solution of 688 mg (2.41 mmol) of dibromobarbituric acid in 10 mL of THF. The colorless solution was heated at reflux for 20 h, cooled to room temperature and partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution. The organic phase was separated and the aqueous phase re-extracted with ethyl acetate. The combined organic phase was washed with water, brine, dried(MgSO4) and the solvent removed in vacuo. Flash chromatography (silica gel, 40-50% dichloromethane-hexanes) afforded 337 mg (48%) of the title compound: 1H NMR (400 MHz, CDCl3) 6.87 (s, 1H), 4.39 (s, 2H), 2.38 (s, 3H).

Workup

  1. temperatureThe colorless solution was heated
  2. temperatureat reflux for 20 h
  3. custompartitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution
  4. customThe organic phase was separated
  5. extractionthe aqueous phase re-extracted with ethyl acetate
  6. washThe combined organic phase was washed with water, brine, dried(MgSO4)
  7. customthe solvent removed in vacuo

Sources & evidence

ORD record
ord-a9ad8e1da8df415ca97bd693f35e8797
Source dataset
uspto-grants-1998_01
Patent number
US05705515

Reaction notes

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