Sulfuric Acid → 4-Methoxy cinnamic acid

HRID 327915Notes

Reaction equation

HRID 327915 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6](N)=[CH:5][CH:4]=1.S(=O)(=O)(O)O.N([O-])=O.[Na+].[C:19]([OH:23])(=[O:22])[CH:20]=[CH2:21].[OH-].[Na+]>C(O)(=O)C.C(OCC)(=O)C.O.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].C(N)(C)(C)C.C1(P(C2C=CC=CC=2)CCP(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH:21]=[CH:20][C:19]([OH:23])=[O:22])=[CH:5][CH:4]=1

Participants

12

Reactant 5

HCID 1118Sulfuric AcidHCID 6581Acrylic AcidHCID 7732P-AnisidineHCID 14798Sodium HydroxideHCID 23668193Sodium Nitrite

Product 1

HCID 132454-Methoxy cinnamic acidYield 67.4%

Reagents, catalysts & solvents 6

HCID 6385Tert-ButylamineCatalystHCID 742671,2-Bis(diphenylphosphino)ethaneCatalystHCID 6505921(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one; palladiumCatalystHCID 176Acetic AcidSolventHCID 962WaterSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

Anisidine (12.3 g) was dissolved in 30 ml acetic acid and 25 ml water and cooled to 10° C. 98% Sulfuric acid (10 ml) was added with cooling. Sodium nitrite (6.9 g in 20 ml water) was then added at 0°-2° C. over 1 hour with stirring. t-Butylamine (0.05 g) was then added and after 10 minutes, Pd(dba)2 (1.0 g) and 0.07 g of 1,2-bis(diphenylphosphino)ethane (diphos) in 50 ml ethyl acetate were added. Acrylic acid (10.3 ml) was then added slowly over 10 minutes. The reaction mixture was allowed to warm to room temperature. After 22 hours under nitrogen, the mixture was neutralized with 30% sodium hydroxide solution (33 g) diluted with 500 ml water. The aqueous solution was separated, neutralized with 10% sulfuric acid to give 12 g of p-methoxycinnamic acid as a solid precipitate which was filtered off (m.p. 165°-170° C.) (67.4% yield).

Workup

  1. temperaturewith cooling
  2. customThe aqueous solution was separated

Sources & evidence

ORD record
ord-bb564da2c90a40409bace5a0cfebe879
Source dataset
uspto-grants-1993_12
Patent number
US05274171

Reaction notes

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