Hydrochloric Acid → (2E)-4-(3,4-Dimethoxyphenyl)-4-oxo-2-butenoic acid

HRID 1373450Notes

Reaction equation

HRID 1373450 reaction equation
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.[Cl-].[Al+3].[Cl-].[Cl-].[CH3:12][O:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[O:20][CH3:21].Cl>ClC1C=CC=CC=1>[CH3:12][O:13][C:14]1[CH:19]=[C:18]([C:4](=[O:5])/[CH:3]=[CH:2]/[C:1]([OH:6])=[O:7])[CH:17]=[CH:16][C:15]=1[O:20][CH3:21]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 7043VeratroleHCID 7923Maleic AnhydrideHCID 6451240Aluminum(III) Chloride2×

Product 1

HCID 6444386(2E)-4-(3,4-Dimethoxyphenyl)-4-oxo-2-butenoic acidYield 62.1%

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent

Conditions

Temperature
10 °C

Procedure

Into a 500 ml four-neck flask were charged 66.9 g (0.682 mol) of maleic anhydride and 150 ml of chlorobenzene under a nitrogen atmosphere. Then, the whole was cooled to 10° C. or lower and 67.6 g (0.507 mol) of aluminum chloride was added thereto. While temperature was maintained at 10 to 15° C., 25 ml (0.195 mol) of 1,2-dimethoxybenzene was added dropwise, followed by 48 hours of reaction at 20 to 30° C. After termination of the reaction was confirmed by HPLC analysis, the reaction solution was added dropwise to 200 ml of a 1N hydrochloric acid aqueous solution cooled to 0° C. to decompose excess aluminum chloride. The resulting mixture was extracted with 400 ml of ethyl acetate and washing was conducted twice with 200 ml of a 1N hydrochloric acid aqueous solution. The organic layer was washed three times with 200 ml of a saturated sodium hydrogen carbonate aqueous solution to extract (E)-4-(3,4-dimethoxyphenyl)-4-oxo-2-butenoic acid into the aqueous layer, followed by adjusting the aqueous layer to pH 2.0. After 24 h of stirring at 5° C., filtration was carried out to obtain 28.6 g (yield 62.1%) of the aimed compound as light yellow crystals. As a result of HPLC analysis, the purity was found to be 96.5%.

Workup

  1. temperatureWhile temperature was maintained at 10 to 15° C.
  2. customfollowed by 48 hours of reaction at 20 to 30° C
  3. temperaturecooled to 0° C.
  4. extractionThe resulting mixture was extracted with 400 ml of ethyl acetate
  5. washwashing
  6. washThe organic layer was washed three times with 200 ml of a saturated sodium hydrogen carbonate aqueous solution
  7. extractionto extract (E)-4-(3,4-dimethoxyphenyl)-4-oxo-2-butenoic acid into the aqueous layer
  8. filtrationfiltration

Sources & evidence

ORD record
ord-d5ebda845fd945779b784f442322e084
Source dataset
uspto-grants-2007_01
Patent number
US07161022B2

Reaction notes

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