Propionic anhydride → 3-(3,4-Difluorophenyl)-2-methylprop-2-enoic acid

HRID 1609630Notes

Reaction equation

HRID 1609630 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[F:10])[CH:5]=O.[C:11]([O:15]C(=O)CC)(=[O:14])[CH2:12][CH3:13].C([O-])(=O)CC.[Na+]>O>[F:1][C:2]1[CH:3]=[C:4]([CH:7]=[CH:8][C:9]=1[F:10])[CH:5]=[C:12]([CH3:13])[C:11]([OH:15])=[O:14]

Participants

5

Reactant 3

HCID 31263Propionic anhydrideHCID 5880883,4-DifluorobenzaldehydeHCID 2723816Sodium Propionate

Product 1

HCID 539805853-(3,4-Difluorophenyl)-2-methylprop-2-enoic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 2.88 g. (0.02 mole) of 3,4-difluorobenzaldehyde, 3.24 g. (0.025 mole) of propionic anhydride and 0.92 g. (0.02 mole) of sodium propionate under nitrogen is heated at 135° with a magnetic stirrer for 20 hours. The reaction mixture is poured onto 50 ml. of water. A solid precipitates that dissolves when 50 ml. of saturated K2CO3 is added with stirring. The basic solution is extracted with ether (2×100 ml.). The aqueous phase is then poured into an excess of concentrated HCl and ice. The precipitated white solid is filtered and dried to give 3,4-difluoro-α-methylcinnamic acid, M.P. 122°-125°.

Workup

  1. additionA mixture of 2.88 g
  2. additionThe reaction mixture is poured onto 50 ml
  3. customA solid precipitates
  4. dissolutionthat dissolves when 50 ml
  5. additionof saturated K2CO3 is added
  6. extractionThe basic solution is extracted with ether (2×100 ml.)
  7. additionThe aqueous phase is then poured into an excess of concentrated HCl and ice
  8. filtrationThe precipitated white solid is filtered
  9. customdried

Sources & evidence

ORD record
ord-dc2c68c0deff4e93980b52ce78da2bcb
Source dataset
uspto-grants-1995_03
Patent number
US05401774

Reaction notes

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