Hydroxyamine hydrochloride → 8-Bromo-5,6-difluoro-2,3-dihydrochromen-4-one oxime

HRID 1363195Notes

Reaction equation

HRID 1363195 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([F:14])[C:5]([F:13])=[C:6]2[C:11]=1[O:10][CH2:9][CH2:8][C:7]2=O.Cl.[NH2:16][OH:17].C([O-])(=O)C.[Na+]>C(O)C.CCOC(C)=O>[Br:1][C:2]1[CH:3]=[C:4]([F:14])[C:5]([F:13])=[C:6]2[C:11]=1[O:10][CH2:9][CH2:8][C:7]2=[N:16][OH:17]

Participants

6

Reactant 3

HCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium AcetateHCID 669706288-Bromo-5,6-difluorochroman-4-one

Product 1

HCID 866101588-Bromo-5,6-difluoro-2,3-dihydrochromen-4-one oximeYield 94.9%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 8-bromo-5,6-difluoro-2,3-dihydrochromen-4-one (7.2 mmol) in 40 mL of ethanol was added hydroxylamine hydrochloride (0.55 g, 7.9 mmol) and sodium acetate (0.65 g, 7.9 mmol). This mixture heated at reflux for 20 hrs. The mixture was cooled, diluted with EtOAc, washed with water and brine, and then dried over Na2SO4. Concentration of the solvent provided the title compound as a white solid (1.9 g). 1H NMR (300 MHz, 10% CD3OD in CDCl3): δ 7.3 (t, 1H), 4.2 (t, 2H), 2.9 (t, 2H).

Workup

  1. temperatureThis mixture heated
  2. temperatureat reflux for 20 hrs
  3. temperatureThe mixture was cooled
  4. washwashed with water and brine
  5. dry with materialdried over Na2SO4

Sources & evidence

ORD record
ord-4249289ae336456ca75101df126c97c7
Source dataset
uspto-grants-2011_02
Patent number
US07884109B2

Reaction notes

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