Ethanol → ethyl (2S)-2-amino-3-(3,4-dimethoxyphenyl)propanoate

HRID 903627Notes

Reaction equation

HRID 903627 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:12]=[CH:13][C:14]=1[O:15][CH3:16])[CH2:6][C@@H:7]([C:9]([OH:11])=[O:10])[NH2:8].OS(O)(=O)=O.C([O-])([O-])=O.[K+].[K+].[CH2:28](O)[CH3:29]>O>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH2:6][C@@H:7]([C:9]([O:11][CH2:28][CH3:29])=[O:10])[NH2:8])[CH:12]=[CH:13][C:14]=1[O:15][CH3:16]

Participants

6

Reactant 4

HCID 702EthanolHCID 1118Sulfuric AcidHCID 11430Potassium CarbonateHCID 106329463,4-Dimethoxyphenylalanine, L-

Product 1

HCID 10060820ethyl (2S)-2-amino-3-(3,4-dimethoxyphenyl)propanoateYield 51%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A 47 g (0.21 mole) portion of 3,4-dimethoxyphenylalanine in 450 ml of absolute ethanol was treated with 31 ml of concentrated H2SO4. The reaction mixture was refluxed for 5 hours and poured into 1.6 l. of H2O. The solution was basified with a solution of 61 g of K2CO3 in 200 ml of water. The basified solution was extracted with three 600 ml portions of ethyl acetate. The combined extracts were washed with 1.4 l. of water, dried over MgSO4 overnight and filtered. The filtrate was concentrated under reduced pressure to give 27 g (51%) of the desired product, a light yellow-brown viscous oil which crystallized upon refrigeration.

Workup

  1. temperatureThe reaction mixture was refluxed for 5 hours
  2. additionpoured into 1.6 l
  3. extractionThe basified solution was extracted with three 600 ml portions of ethyl acetate
  4. washThe combined extracts were washed with 1.4 l
  5. dry with materialof water, dried over MgSO4 overnight
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-bb0767e48761447486f2da9168ac4d83
Source dataset
uspto-grants-1980_10
Patent number
US04228303

Reaction notes

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