Nitric Acid → 6-nitro-3,4-dihydro-2H-1-benzopyran-4-one

HRID 1779958Notes

Reaction equation

HRID 1779958 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[CH2:3][CH2:2]1.[N+:12]([O-])([OH:14])=[O:13]>>[N+:12]([C:7]1[CH:6]=[C:5]2[C:10](=[CH:9][CH:8]=1)[O:1][CH2:2][CH2:3][C:4]2=[O:11])([O-:14])=[O:13]

Participants

3

Reactant 2

HCID 944Nitric AcidHCID 68110Chromanone

Product 1

HCID 52288316-nitro-3,4-dihydro-2H-1-benzopyran-4-one

Procedure

After cooling 40 ml of fuming nitric acid to -30° to -35° C., 5.8 g of 4-chromanone was added with stirring over about 30 minutes and further stirred for 30 minutes at the same temperature. The reaction mixture was successively poured into ice water and extracted with 500 ml of ethyl acetate. The organic layer was dried with anhydrous magnesium sulfate and the solvent was distilled off under reduced pressure. The crude product thus obtained was washed with a solvent mixture, n-hexane:ethyl acetate=1:1, to give 5.4 g of 6-nitro-4-chromanone.

Workup

  1. stirringfurther stirred for 30 minutes at the same temperature
  2. extractionextracted with 500 ml of ethyl acetate
  3. dry with materialThe organic layer was dried with anhydrous magnesium sulfate
  4. distillationthe solvent was distilled off under reduced pressure
  5. customThe crude product thus obtained
  6. washwas washed with a solvent mixture, n-hexane

Sources & evidence

ORD record
ord-a071dd13e9bf47d2809a67309cffffd2
Source dataset
uspto-grants-1997_05
Patent number
US05629321

Reaction notes

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