Acetyl chloride → 5,8-Dimethoxy-2-acetyl-3,4-dihydronaphthalene

HRID 897177Notes

Reaction equation

HRID 897177 reaction equation
[CH3:1][O:2][C:3]1[CH:12]=[CH:11][C:10]([O:13][CH3:14])=[C:9]2[C:4]=1[CH2:5][CH2:6][CH:7]=[CH:8]2.[C:15](Cl)(=[O:17])[CH3:16].[Cl-].[Cl-].[Cl-].[Al+3]>>[C:15]([C:6]1[CH2:7][CH2:8][C:9]2[C:4](=[C:3]([O:2][CH3:1])[CH:12]=[CH:11][C:10]=2[O:13][CH3:14])[CH:5]=1)(=[O:17])[CH3:16]

Participants

4

Reactant 3

HCID 6367Acetyl chlorideHCID 2676515,8-dimethoxy-1,2-dihydronaphthalene2×HCID 6451240Aluminum(III) Chloride2×

Product 1

HCID 110642935,8-Dimethoxy-2-acetyl-3,4-dihydronaphthalene

Procedure

In spite of the fact that in literature the attempts of acylating the compound II were reported as fruitless or non interesting because of the low yields, the 5,8-dimethoxy-3,4-dihydronaphthalene II is treated with acetyl chloride in the presence of an excess of aluminium trichloride, preferably 5-9 moles of aluminium trichloride for one mole of acyl chloride, at the temperature of −35°+25° C., preferably at 0° C. After the usual work-up and crystallisation with ethyl acetate, the product, 2-acetyl-5,8-dimethoxy-3,4-dihydronaphthalene is obtained in yields higher than 70%.

Workup

  1. customat the temperature of −35°+25° C.
  2. custompreferably at 0° C
  3. customAfter the usual work-up and crystallisation with ethyl acetate

Sources & evidence

ORD record
ord-72723d1aea884e46aebb7137c57153cc
Source dataset
uspto-grants-2005_07
Patent number
US06921841B2

Reaction notes

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