Chromanone → 4H-1-Benzopyran-4-one, 2,3-dihydro-, oxime

HRID 1045659Notes

Reaction equation

HRID 1045659 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=O)[CH2:3][CH2:2]1.Cl.[NH2:13][OH:14]>N1C=CC=CC=1>[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[N:13][OH:14])[CH2:3][CH2:2]1

Participants

4

Reactant 2

HCID 68110ChromanoneHCID 443297Hydroxyamine hydrochloride

Product 1

HCID 44866984H-1-Benzopyran-4-one, 2,3-dihydro-, oximeYield 88%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

Chroman-4-one (46.5 g, 314 mmol) was dissolved in pyridine (160 ml) and hydroxylamine hydrochloride (51 g, 734 mmol) was added to this solution. The solution was refluxed for 8 hours and then cooled to room temperature. The solvent was evaporated under reduced pressure and the residue was partitioned between water and chloroform. The organic layer was washed with 1N aqueous hydrochloric acid and brine, dried over magnesium sulfate, and concentrated under reduced pressure. The precipitate was filtered, washed with diisopropylether, and dried to afford chroman-4-one oxime (22.9 g, 275 mmol, 88%) as white crystals.

Workup

  1. temperatureThe solution was refluxed for 8 hours
  2. customThe solvent was evaporated under reduced pressure
  3. customthe residue was partitioned between water and chloroform
  4. washThe organic layer was washed with 1N aqueous hydrochloric acid and brine
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated under reduced pressure
  7. filtrationThe precipitate was filtered
  8. washwashed with diisopropylether
  9. customdried

Sources & evidence

ORD record
ord-e7ea90a1fd624505a632e27d606a48d1
Source dataset
uspto-grants-2013_10
Patent number
US08569294B2

Reaction notes

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