Acetic Anhydride → alpha-Methylene-4-methoxybenzenepropanoic acid

HRID 620515Notes

Reaction equation

HRID 620515 reaction equation
[CH3:1][O:2][C:3]1[CH:16]=[CH:15][C:6]([CH2:7][CH:8]([C:12](O)=O)[C:9]([OH:11])=[O:10])=[CH:5][CH:4]=1.C(OC(=O)C)(=O)C>O>[CH2:12]=[C:8]([CH2:7][C:6]1[CH:5]=[CH:4][C:3]([O:2][CH3:1])=[CH:16][CH:15]=1)[C:9]([OH:11])=[O:10]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 143920722-(4-Methoxybenzyl)Malonic Acid

Product 1

HCID 13817412alpha-Methylene-4-methoxybenzenepropanoic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

4-Methoxybenzylmalonic acid, (20.2 g., 0.09 mol) was suspended in N,N,N1,N1 -tetramethylmethanediamine (45 ml). Acetic anhydride (45 ml) was added dropwise, keeping the temperature below 45° C. by cooling in an ice-bath as necessary. The resulting clear solution was stirred for 11/2 hour at ambient temperature and then was poured into ice and water. The white solid product was collected, combined with comparable product from a second 0.083 mol run, and dried at 0.1 mm at room temperature to give 22.4 g. (68%) of product, m.p. 88°-91° C. A sample recrystallized from ether-petroleum ether melted at 90°-93° C.

Workup

  1. customthe temperature below 45° C.
  2. temperatureby cooling in an ice-bath as necessary
  3. customThe white solid product was collected
  4. customdried at 0.1 mm at room temperature
  5. customto give 22.4 g
  6. customA sample recrystallized from ether-petroleum ether melted at 90°-93° C.

Sources & evidence

ORD record
ord-8bc0a6b35ed548c5b256936dd5294464
Source dataset
uspto-grants-1989_04
Patent number
US04820848

Reaction notes

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