Acetic Acid → Dimethyl-2-oxo-3-phenylpropyl phosphonate

HRID 258814Notes

Reaction equation

HRID 258814 reaction equation
[CH3:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4].P(=O)([O-])[O-].[CH2:12]([Li])[CH2:13][CH2:14][CH3:15].C(O)(=O)C.[O:21]1[CH2:25][CH2:24][CH2:23][CH2:22]1>CCCCCC>[O:21]=[C:25]([CH2:24][C:23]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:22]=1)[CH2:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4]

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 406CID 406HCID 8028TetrahydrofuranHCID 12958Dimethyl methylphosphonateHCID 178418339Butyllithium

Product 1

HCID 12805884Dimethyl-2-oxo-3-phenylpropyl phosphonateYield 29%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

A solution of 6.2 g (50 mmoles) dimethyl methylphosphonate (Aldrich) in 125 ml dry tetrahydrofuran was cooled to -78° in a dry nitrogen atmosphere. To the stirred phosphonate solution was added 21 ml of 2.37 M n-butyllithium in hexane solution (Alfa Inorganics, Inc.) dropwise over a period of 18 minutes at such a rate that the reaction temperature never rose above -65°. After an additional 5 minutes stirring at -78°, 7.5 g (50.0 mmole) methyl was added dropwise at a rate that kept the reaction temperature less than -70° (20 minutes). After 3.5 hours at -78° the reaction mixture was allowed to warm to ambient temperature, neutralized with 6 ml acetic acid and rotary evaporated to a white gel. The gelatonous material was taken up in 75 ml water, the aqueous phase extracted with 100 ml portions of chloroform (3x), the combined organic extracts were backwashed (50 cc H2O), dried (MgSO4), and concentrated (water aspirator) to a crude residue and distilled, b.p. 134°-5° (<0.1 mm) to give 3.5 g (29%) dimethyl 2-oxo-3-phenylpropylphosphonate.

Workup

  1. addition7.5 g (50.0 mmole) methyl was added dropwise at a rate that
  2. customthe reaction temperature less than -70° (20 minutes)
  3. waitAfter 3.5 hours at -78° the reaction mixture was allowed
  4. customrotary evaporated to a white gel
  5. extractionthe aqueous phase extracted with 100 ml portions of chloroform (3x)
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated (water aspirator) to a crude residue
  8. distillationdistilled

Sources & evidence

ORD record
ord-32fd69083278472ab32cc006ab113678
Source dataset
uspto-grants-1977_07
Patent number
US04035360

Reaction notes

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