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

HRID 1373457Notes

Reaction equation

HRID 1373457 reaction equation
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.S(OCC)(OCC)(=O)=O.[Cl-].[Al+3].[Cl-].[Cl-].[CH3:21][O:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][C:24]=1[O:29][CH3:30].Cl.[I-].[Na+].Cl[Si](C)(C)C>[Cu](I)I.ClC1C=CC=CC=1>[CH3:21][O:22][C:23]1[CH:28]=[C:27]([C:4](=[O:5])/[CH:3]=[CH:2]/[C:1]([OH:6])=[O:7])[CH:26]=[CH:25][C:24]=1[O:29][CH3:30]

Participants

10

Reactant 7

HCID 313Hydrochloric AcidHCID 5238Sodium IodideHCID 6163Diethyl SulfateHCID 6397ChlorotrimethylsilaneHCID 7043VeratroleHCID 7923Maleic AnhydrideHCID 6451240Aluminum(III) Chloride2×

Product 1

HCID 6444386(2E)-4-(3,4-Dimethoxyphenyl)-4-oxo-2-butenoic acidYield 54.2%

Reagents, catalysts & solvents 2

HCID 83717Copper iodideCatalystHCID 7964ChlorobenzeneSolvent

Conditions

Temperature
10 °C

Procedure

Into a 500 ml four-neck flask were charged 66.9 g (0.682 mol) of maleic anhydride, 150 ml of chlorobenzene, 71.6 ml (0.546 mol) of diethyl sulfate, and 0.186 g (0.975 mmol) of copper iodide 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 2 hours of reaction. 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. After liquid separation, the organic layer was washed with 200 ml of a 10% sodium bicarbonate aqueous solution to remove excess maleic anhydride. Then, 42.9 g (0.286 mol) of sodium iodide and 31.1 g (0.286 mol) of chlorotrimethylsilane were added to the organic layer, followed by heating and refluxing. After completion of the reaction, the organic layer was washed with 100 ml of a 5% sodium thiosulfate aqueous solution and 100 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 conducted to obtain 24.9 g (yield 54.2%) of the aimed compound as light yellow crystals. As a result of HPLC analysis, the purity was found to be 98.5%.

Workup

  1. temperatureWhile temperature was maintained at 10 to 15° C.
  2. customfollowed by 2 hours of reaction
  3. temperaturecooled to 0° C.
  4. customAfter liquid separation
  5. washthe organic layer was washed with 200 ml of a 10% sodium bicarbonate aqueous solution
  6. customto remove excess maleic anhydride
  7. temperatureby heating
  8. temperaturerefluxing
  9. customAfter completion of the reaction
  10. washthe organic layer was washed with 100 ml of a 5% sodium thiosulfate aqueous solution and 100 ml of a saturated sodium hydrogen carbonate aqueous solution
  11. extractionto extract (E)-4-(3,4-dimethoxyphenyl)-4-oxo-2-butenoic acid into the aqueous layer
  12. filtrationfiltration

Sources & evidence

ORD record
ord-3060b8dc840842c4a5178841c545095f
Source dataset
uspto-grants-2007_01
Patent number
US07161022B2

Reaction notes

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