Methanol → 6,7-Dichloro-2,3-dihydro-4H-1-benzopyran-4-one oxime

HRID 1659894Notes

Reaction equation

HRID 1659894 reaction equation
[Cl:1][C:2]1[C:3]([Cl:13])=[CH:4][C:5]2[O:10][CH2:9][CH2:8][C:7](=O)[C:6]=2[CH:12]=1.CO.C(=O)([O-])[O-].[K+].[K+].Cl.[NH2:23][OH:24]>O>[Cl:1][C:2]1[C:3]([Cl:13])=[CH:4][C:5]2[O:10][CH2:9][CH2:8][C:7](=[N:23][OH:24])[C:6]=2[CH:12]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 11430Potassium CarbonateHCID 443297Hydroxyamine hydrochlorideHCID 126644086,7-Dichloro-2,3-dihydro-4H-1-benzopyran-4-one

Product 1

HCID 857730826,7-Dichloro-2,3-dihydro-4H-1-benzopyran-4-one oxime

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 6,7-dichloro-2,3-dihydro-4H-1-benzopyran-4-one (59.7 g), methanol (750 ml), water (75 ml), potassium carbonate (76 g), hydroxylamine HCl (76.4 g) was heated at reflux for 4 hours, then poured into ice-water: the oxime of 6,7-dichloro-2,3-dihydro-4H-1-benzopyran-4-one was filtered off, washed with water, with a small volume of ether, then dried in air. Yield: 62.7 g; m.p. 192°-193°.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 4 hours
  3. filtrationthe oxime of 6,7-dichloro-2,3-dihydro-4H-1-benzopyran-4-one was filtered off
  4. washwashed with water, with a small volume of ether
  5. customdried in air

Sources & evidence

ORD record
ord-4e991763a17a4803843d94d2c2b163aa
Source dataset
uspto-grants-1981_12
Patent number
US04305954

Reaction notes

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