4-Hydroxybenzaldehyde → 4-Hydroxy-alpha-methylcinnamic acid

HRID 579921Notes

Reaction equation

HRID 579921 reaction equation
[OH:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=O)=[CH:4][CH:3]=1.[C:10]([O:14]C(=O)CC)(=[O:13])[CH2:11][CH3:12].C([O-])(=O)CC.[K+].C(=O)([O-])[O-].[Na+].[Na+].[OH-].[Na+].Cl>C(O)C.O>[OH:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=[C:11]([CH3:12])[C:10]([OH:14])=[O:13])=[CH:4][CH:3]=1

Participants

9

Reactant 6

HCID 1264-HydroxybenzaldehydeHCID 313Hydrochloric AcidHCID 10340Sodium CarbonateHCID 14798Sodium HydroxideHCID 31263Propionic anhydrideHCID 23663619Potassium propionate

Product 1

HCID 2191964-Hydroxy-alpha-methylcinnamic acidYield 34.3%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent2×

Procedure

At 135° C., 122 g of 4-hydroxybenzaldehyde, 163 g of propionic anhydride and 112 g of potassium propionate were reacted with stirring for 30 hours, the reaction mixture was dropped into 1.5 l of distilled water, and sodium carbonate was added to form an aqueous alkaline solution. The unreacted 4-hydroxybenzaldehyde was removed and concentrated hydrochloric acid was added to render the solution acidic and precipitate the reaction product. The precipitate was recovered by filtration and washed with water to obtain 85 g of a crude product. The precipitate was dissolved in a solution comprising 150 g of water, 150 g of ethanol and 30 g of sodium hydroxide, and the solution was refluxed for 2 hours and dropped into a liquid comprising concentrated hydrochloric acid and ice to precipitate the reaction product. The precipitate was recovered by filtration, washed repeatedly with distilled water and dried to obtain 61 g of crude 4-hydroxy-α-methylcinnamic acid. A product (refined 4-hydroxy-α-methylcinnamic acid) obtained by recrystallizing this crude 4-hydroxy-αmethylcinnamic acid from hot water was used for the subsequent reaction.

Workup

  1. additionwas added
  2. customto form an aqueous alkaline solution
  3. customThe unreacted 4-hydroxybenzaldehyde was removed
  4. additionconcentrated hydrochloric acid was added
  5. customprecipitate the reaction product
  6. filtrationThe precipitate was recovered by filtration
  7. washwashed with water
  8. customto obtain 85 g of a crude product
  9. dissolutionThe precipitate was dissolved in a solution
  10. temperaturethe solution was refluxed for 2 hours
  11. customto precipitate the reaction product
  12. filtrationThe precipitate was recovered by filtration
  13. washwashed repeatedly with distilled water
  14. customdried

Sources & evidence

ORD record
ord-295c45d91c4845d4ac88b75e5bc5f2c1
Source dataset
uspto-grants-1988_06
Patent number
US04751018

Reaction notes

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