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

HRID 259080Notes

Reaction equation

HRID 259080 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 reduction temperature never rose above -65°. After an additional 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 (3×), 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. customthe reaction temperature less than -70° (20 minutes)
  2. waitAfter 3.5 hours at -78°
  3. customrotary evaporated (water aspirator) to a white gel
  4. extractionthe aqueous phase extracted with 100 ml portions of chloroform (3×)
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated (water aspirator) to a crude residue
  7. distillationdistilled

Sources & evidence

ORD record
ord-48ba695405b545ce9c2820731bd026e9
Source dataset
uspto-grants-1977_07
Patent number
US04036832

Reaction notes

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