CID 406 → Dimethyl-2-oxo-3-phenylpropyl phosphonate

HRID 596549Notes

Reaction equation

HRID 596549 reaction equation
[CH3:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4].P(=O)([O-])[O-].C([Li])CCC.[C:17]1([CH2:23][C:24](OC)=[O:25])[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>O1CCCC1.CCCCCC.C(O)(=O)C>[O:25]=[C:24]([CH2:23][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)[CH2:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4]

Participants

8

Reactant 4

HCID 406CID 406HCID 7559Methyl phenylacetateHCID 12958Dimethyl methylphosphonateHCID 178418339Butyllithium

Product 1

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

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 8028TetrahydrofuranSolventHCID 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 addition 5 minutes stirring at -78°, 7.5 g (50.0 mmole) methyl phenylacetate 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 (water aspirator) to a white gel. The gelatinous 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 (2a).

Workup

  1. additionAfter an addition 5 minutes
  2. customthe reaction temperature less than -70° (20 minutes)
  3. customrotary evaporated (water aspirator) to a white gel
  4. extractionthe aqueous phase extracted with 100 ml portions of chloroform (3x)
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated (water aspirator) to a crude residue
  7. distillationdistilled

Sources & evidence

ORD record
ord-3a2d19f5ecfc46e19891cb31462afbdb
Source dataset
uspto-grants-1977_03
Patent number
US04011262

Reaction notes

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