CID 406 → Dimethyl 2-Oxo-3-(2-norbornyl)propylphosphonate

HRID 261925Notes

Reaction equation

HRID 261925 reaction equation
[CH3:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4].P(=O)([O-])[O-].C([Li])CCC.[CH:17]12[CH2:23][CH:20]([CH2:21][CH2:22]1)[CH2:19][CH:18]2[CH2:24][C:25](OC)=[O:26]>O1CCCC1.CCCCCC.C(O)(=O)C>[O:26]=[C:25]([CH2:24][CH:18]1[CH2:19][CH:20]2[CH2:23][CH:17]1[CH2:22][CH2:21]2)[CH2:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4]

Participants

8

Reactant 4

HCID 406CID 406HCID 12958Dimethyl methylphosphonateHCID 13403348Methyl 2-{bicyclo[2.2.1]heptan-2-yl}acetateHCID 178418339Butyllithium

Product 1

HCID 21321713Dimethyl 2-Oxo-3-(2-norbornyl)propylphosphonate

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

A solution of 63.9 g (0.516 mole) dimethyl methylphosphonate (Aldrich) in 645 ml dry tetrahydrofuran was cooled to -78° in a dry nitrogen atmosphere. To the stirred phosphonate solution was added 251 ml of 2.2 M n-butyllithium in hexane solution (Alfa Inorganics, Inc.) dropwise over a period of 40 minutes at such a rate that the reaction temperature never rose about -65°. After an additional 5 minutes stirring at -78°, 43.5 g (0.258 mole) methyl (2-norbornyl)acetate was added dropwise at a rate that kept the reaction temperature less than -70° (20 minutes). After 1.0 hour at -78° the reaction mixture was allowed to warm to ambient temperature, neutralized with 35 ml acetic acid and rotary evaporated to a white gel. The gelatinous material was taken up in 50 ml water, the aqueous phase extracted with 100 ml portions of chloroform (4x), the combined organic extracts were backwashed (50 cc H2O), dried (MgSO4), and concentrated (water aspirator) to a crude residue and distilled, dimethyl 2-oxo-3-(2-norbornyl) propylphosphonate (b.p. 138°-141°/0.3 mm).

Workup

  1. customthe reaction temperature less than -70° (20 minutes)
  2. waitAfter 1.0 hour at -78° the reaction mixture was allowed
  3. customrotary evaporated to a white gel
  4. extractionthe aqueous phase extracted with 100 ml portions of chloroform (4x)
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated (water aspirator) to a crude residue
  7. distillationdistilled

Sources & evidence

ORD record
ord-e46a6230018340348bda05f58aa5ab2c
Source dataset
uspto-grants-1979_05
Patent number
US04152527

Reaction notes

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