CID 406 → Dimethyl (3,3-dimethyl-2-oxoheptyl)phosphonate

HRID 1606580Notes

Reaction equation

HRID 1606580 reaction equation
[CH3:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4].P(=O)([O-])[O-].C([Li])CCC.[CH3:17][C:18]([CH3:27])([CH2:23][CH2:24][CH2:25][CH3:26])[C:19](OC)=[O:20]>CCCCCC.O1CCCC1>[O:20]=[C:19]([C:18]([CH3:27])([CH3:17])[CH2:23][CH2:24][CH2:25][CH3:26])[CH2:1][P:2](=[O:7])([O:5][CH3:6])[O:3][CH3:4]

Participants

7

Reactant 4

HCID 406CID 406HCID 12958Dimethyl methylphosphonateHCID 5275562,2-Dimethyl-hexanoic acid methyl esterHCID 178418339Butyllithium

Product 1

HCID 13018035Dimethyl (3,3-dimethyl-2-oxoheptyl)phosphonate

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

A solution of 18.4 g. (0.116 moles) dimethyl methylphosphonate (Aldrich) in 200 ml. dry tetrahydrofuran is cooled to -78° in a dry nitrogen atmosphere. To the stirred phosphonate solution is added 67.3 ml. of 1.90 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 above -65°. After an additional 5 minutes stirring at -78°, 10.2 g. (58.1 mmoles) methyl 2,2-dimethylhexanoate is added dropwise at a rate that kept the reaction temperature less than -70°(20 minutes). After 1.0 hour at -78° the reaction mixture is allowed to warm to ambient temperature, neutralized with 10 ml. acetic acid and rotary evaporated to a white gel. The gelatinous material is taken up in 75 ml. water, the aqueous phase extracted with 100 ml. portions of chloroform (3×), the combined organic extracts are backwashed (50 cc H2O), dried (MgSO4), and concentrated (water aspirator) to a crude residue and distilled (b.p. 80°-85° at 0.05 mm) to give dimethyl 2-oxo-3,3-dimethylheptylphosphonate.

Workup

  1. customthe reaction temperature less than -70°(20 minutes)
  2. waitAfter 1.0 hour at -78° the reaction mixture is allowed
  3. customacetic acid and rotary evaporated to a white gel
  4. extractionwater, the aqueous phase extracted with 100 ml
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated (water aspirator) to a crude residue
  7. distillationdistilled (b.p. 80°-85° at 0.05 mm)

Sources & evidence

ORD record
ord-21f883bbe4b44cef9f7daa53e79aae48
Source dataset
uspto-grants-1976_04
Patent number
US03953466

Reaction notes

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