2-Phenylpropionic acid → 2,5,5-trimethyl-2-phenylhexanoic Acid

HRID 494574Notes

Reaction equation

HRID 494574 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[C:11]1([CH:17]([CH3:21])[C:18]([OH:20])=[O:19])[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.Br[CH2:23][CH2:24][C:25]([CH3:28])([CH3:27])[CH3:26]>O1CCCC1>[CH3:21][C:17]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)([CH2:23][CH2:24][C:25]([CH3:28])([CH3:27])[CH3:26])[C:18]([OH:20])=[O:19]

Participants

5

Reactant 3

HCID 102962-Phenylpropionic acidHCID 1371371-Bromo-3,3-dimethylbutaneHCID 2733832Lithium Hexamethyldisilazide

Product 1

HCID 252601992,5,5-trimethyl-2-phenylhexanoic AcidYield 96%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Lithium bis(trimethylsilyl)amide (32.3 g, 193 mmol) was added to 80 mL of tetrahydrofuran and the resulting solution was cooled in an ice bath. Addition of a solution of 2-phenyl-propionic acid (11.6 g, 77.3 mmol) in 10 mL of tetrahydrofuran to the reaction solution was followed by addition of 1-bromo-3,3-dimethyl-butane (20.4 g, 124 mmol). The reaction vessel was removed from the cooling bath, placed in a 50° C. oil bath, and the reaction solution was stirred for 17 hours. After concentration, the resulting residue was dissolved in 250 mL of 1 N NaOH, washed with 250 mL of 2:1 hexane/iso-propyl acetate, acidified to pH 1 with 6 N HCl, and extracted with ethyl acetate (3×300 mL). The combined organic layers were dried over Na2SO4 and concentrated to give 17.3 g (96%) of clear oil. 1H NMR (300 MHz, CDCl3): δ ppm 0.86 (s, 9H) 1.09 (m, 2H) 1.56 (s, 3H) 1.99 (m, 2H) 7.33 (m, 5H).

Workup

  1. temperaturethe resulting solution was cooled in an ice bath
  2. customThe reaction vessel was removed from the cooling bath
  3. customplaced in a 50° C.
  4. concentrationAfter concentration
  5. dissolutionthe resulting residue was dissolved in 250 mL of 1 N NaOH
  6. washwashed with 250 mL of 2:1 hexane/iso-propyl acetate
  7. extractionextracted with ethyl acetate (3×300 mL)
  8. dry with materialThe combined organic layers were dried over Na2SO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-65eec61324c145a3af6e022f1de184e0
Source dataset
uspto-grants-2009_05
Patent number
US07538105B2

Reaction notes

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