Methylparaben → Methyl 4-(allyloxy)benzoate

HRID 865538Notes

Reaction equation

HRID 865538 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][CH:3]=1.[CH2:12](Br)[CH:13]=[CH2:14].C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[CH2:14]([O:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:10][CH:11]=1)[CH:13]=[CH2:12]

Participants

5

Reactant 3

HCID 7456MethylparabenHCID 7841Allyl bromideHCID 11430Potassium Carbonate2×

Product 1

HCID 4645407Methyl 4-(allyloxy)benzoate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a nitrogen flushed 5 L three neck round bottom flask fitted with a mechanical stirrer, condenser, and a nitrogen inlet was charged 608 g (4 mol) of methyl 4-hydoxybenzoate, 520 ml (727 g, 6.00 mol, 1.5 eq) of allyl bromide, 663 g (9.6 mol of anhydrous potassium carbonate, and 2.3 L of acetone. The mixture was refluxed with vigorous stirring for 90 min. Additional potassium carbonate, (50 g) was added, and 25 g added again after an additional 50 min. After 20 min (total reaction time of 160 min), the suspension was allowed to cool to ambient temperature and stirred overnight. The mixture was filtered and the cake washed with 3 L of acetone. The solution was concentrated to obtain 788.6 g (theoretical yield 768.9 g) of a pale yellow, almost colorless oil which was used without purification in the next step. The product was a single spot on TLC (silica-1:1 EtOAc/Hex) and the MNR was consistent with methyl 4-allyloxybenzoate.

Workup

  1. customTo a nitrogen flushed 5 L three neck round bottom flask
  2. customfitted with a mechanical stirrer, condenser, and a nitrogen inlet
  3. temperatureThe mixture was refluxed
  4. addition25 g added again after an additional 50 min
  5. waitAfter 20 min (total reaction time of 160 min)
  6. stirringstirred overnight
  7. filtrationThe mixture was filtered
  8. washthe cake washed with 3 L of acetone
  9. concentrationThe solution was concentrated
  10. customto obtain 788.6 g (theoretical yield 768.9 g) of a pale yellow, almost colorless oil which
  11. customwas used without purification in the next step

Sources & evidence

ORD record
ord-2faffbea12564cc396def7b8b3a84b04
Source dataset
uspto-grants-1996_10
Patent number
US05565485

Reaction notes

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