Acetic Acid → 6-Acetyl-2,3,-dihydro-7-methoxy-4-methyl-4H-1-benzopyran

HRID 236981Notes

Reaction equation

HRID 236981 reaction equation
[CH3:1][O:2][C:3]1[CH:13]=[CH:12][C:6]2[CH:7]([CH3:11])[CH2:8][CH2:9][O:10][C:5]=2[CH:4]=1.[C:14](O)(=[O:16])[CH3:15]>C1C=CC=CC=1>[C:14]([C:13]1[C:3]([O:2][CH3:1])=[CH:4][C:5]2[O:10][CH2:9][CH2:8][CH:7]([CH3:11])[C:6]=2[CH:12]=1)(=[O:16])[CH3:15]

Participants

4

Reactant 2

HCID 176Acetic AcidHCID 134970182,3-Dihydro-7-methoxy-4-methyl-4H-1-benzopyran

Product 1

HCID 203045486-Acetyl-2,3,-dihydro-7-methoxy-4-methyl-4H-1-benzopyranYield 95%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

The methyl ether of step (c) (58.0 g) was dissolved in dry benzene (1 l) and glacial acetic acid (22.3 ml) was added. Boron trifluoride gas was bubbled through the reaction mixture for 1 hour and then stirring was continued overnight. The reaction mixture was poured into water, the organic layer was separated and the aqueous phase was extracted with more ether. The organic extracts were washed with sodium bicarbonate solution, then water, and dried. Evaporation gave 67.8 g of the desired product (95%). MS and NMR analysis were correct for the required compound.

Workup

  1. customBoron trifluoride gas was bubbled through the reaction mixture for 1 hour
  2. additionThe reaction mixture was poured into water
  3. customthe organic layer was separated
  4. extractionthe aqueous phase was extracted with more ether
  5. washThe organic extracts were washed with sodium bicarbonate solution
  6. dry with materialwater, and dried
  7. customEvaporation

Sources & evidence

ORD record
ord-ee39bc9dfcbc475b995814706f466f6a
Source dataset
uspto-grants-1979_06
Patent number
US04159273

Reaction notes

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