N,N,N',N'-Tetramethylethylenediamine → ethyl(RS)-2-oxo-3-phenylbutyrate

HRID 324671

Reaction equation

HRID 324671 reaction equation
C([Li])CCC.[C:6]1([CH:12]([CH3:16])[C:13]([OH:15])=O)[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.CN(C)CCN(C)C.[C:25]([O:30][CH2:31][CH3:32])(=[O:29])C([O-])=O.C(=O)([O-])O.[Na+]>CCCCCC.O1CCCC1>[O:15]=[C:13]([CH:12]([C:6]1[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=1)[CH3:16])[C:25]([O:30][CH2:31][CH3:32])=[O:29]

Participants

8

Reactant 5

HCID 8037N,N,N',N'-TetramethylethylenediamineHCID 102962-Phenylpropionic acidHCID 516892Sodium BicarbonateHCID 21943339Ethanedioic acid, monoethyl esterHCID 178418339Butyllithium

Product 1

HCID 11435685ethyl(RS)-2-oxo-3-phenylbutyrateYield 97%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
-70 °C

Procedure

A 1.6 N solution of n-butyllithium in hexane was run dropwise into a solution, cooled to the region of −70° C., of 33 g (0.220 mol) of (RS)-2-phenylpropionic acid in 220 cm3 of tetrahydrofuran and of 44 cm3 of N,N′-tetramethylethylenediamine. After having stirred the reaction mixture for three hours at −70° C., the reaction mixture was returned to a temperature in the region of 20° C. and the solution obtained was run into a solution of 75 cm3 (0.55 mol) of ethyl oxalate in 110 cm3 of tetrahydrofuran, the temperature being maintained at −75° C., for 1 hour. The reaction mixture was hydrolysed with 800 cm3 of a saturated aqueous sodium hydrogencarbonate solution, extracted with three times 100 cm3 of ethyl acetate, washed with three times 50 cm3 of a normal aqueous hydrochloric acid solution, dried over sodium sulphate and concentrated under reduced pressure. 44 g (97%) of ethyl (RS)-2-oxo-3-phenylbutyrate were then obtained in the form of an orange oil, the characteristics of which were as follows:

Workup

  1. customwas returned to a temperature in the region of 20° C.
  2. customthe solution obtained
  3. temperaturethe temperature being maintained at −75° C., for 1 hour
  4. extractionextracted with three times 100 cm3 of ethyl acetate
  5. washwashed with three times 50 cm3 of a normal aqueous hydrochloric acid solution
  6. dry with materialdried over sodium sulphate
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-fa29ffcf227e4afca097cbed42620e38
Source dataset
uspto-grants-2001_04
Patent number
US06218406B1

Linked notes

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