Acetone → 4H-1-Benzopyran-4-one, 2,3-dihydro-6,7-dimethoxy-2,2-dimethyl-

HRID 1607623Notes

Reaction equation

HRID 1607623 reaction equation
[CH3:1][C:2]([CH3:4])=[O:3].[C:5](=[O:8])([O-])[O-].[K+].[K+].[CH3:11]I.OC1C=[C:16]2[C:21](=[CH:22]C=1O)[O:20][C:19]([CH3:26])([CH3:25])[CH2:18][C:17]2=[O:27]>>[CH3:11][O:3][C:2]1[CH:4]=[C:16]2[C:21](=[CH:22][C:1]=1[O:8][CH3:5])[O:20][C:19]([CH3:26])([CH3:25])[CH2:18][C:17]2=[O:27]

Participants

5

Reactant 4

HCID 180AcetoneHCID 6328Methyl iodide2×HCID 11430Potassium CarbonateHCID 126377192,2-Dimethyl-6,7-dihydroxy-4-chromanone

Product 1

HCID 1033734H-1-Benzopyran-4-one, 2,3-dihydro-6,7-dimethoxy-2,2-dimethyl-Yield 95.2%

Procedure

In 100 ml of acetone 4.2 g (20 millimoles) of 6,7-dihydroxy-2,2-dimethyl-4-chromanone are dissolved and to the solution 8.3 g (60 millimoles) of potassium carbonate and 8.5 g (3.8 ml, 60 millimoles) of methyl iodide are added. The reaction mixture is refluxed for 7 hours whereupon a further amount of 2.8 g (1.2 ml, 20 millimoles) of methyl iodide are added. The reaction mixture is heated to boiling for 3 hours, the suspension formed is cooled under stirring, the precipitated inorganic salt is filtered off, washed twice with 20 ml of acetone each and the acetone is removed. The residue is crystallized from 80% ethanol. Thus 4.5 g of the desired compound are obtained, yield 95.2%. Mp.: 105°-106° C.

Workup

  1. additionare added
  2. additionare added
  3. temperatureThe reaction mixture is heated
  4. customthe suspension formed
  5. temperatureis cooled
  6. filtrationthe precipitated inorganic salt is filtered off
  7. washwashed twice with 20 ml of acetone each and the acetone
  8. customis removed
  9. customThe residue is crystallized from 80% ethanol

Sources & evidence

ORD record
ord-83095e0d9e0c484ea7d0a815de648ffd
Source dataset
uspto-grants-1989_09
Patent number
US04866089

Reaction notes

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