Triethyl phosphonoacetate → HCID 53705973, compound

HRID 1196046Notes

Reaction equation

HRID 1196046 reaction equation
[H-].[Na+].[CH3:3][CH2:4][O:5][C:6]([CH2:8]P(OCC)(OCC)=O)=[O:7].[CH3:17][C:18]1([CH3:29])[C:27](=O)[CH2:26][C:25]2[C:20](=[CH:21][CH:22]=[CH:23][CH:24]=2)[O:19]1>O1CCCC1>[CH2:4]([O:5][C:6]([CH2:8][C:27]1[C:18]([CH3:29])([CH3:17])[O:19][C:20]2[C:25]([CH:26]=1)=[CH:24][CH:23]=[CH:22][CH:21]=2)=[O:7])[CH3:3]

Participants

5

Reactant 3

HCID 13345Triethyl phosphonoacetateHCID 24758Sodium hydrideHCID 13047381HCID 13047381, compound

Product 1

HCID 53705973HCID 53705973, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

25 g (0.6 mol) of sodium hydride dispersion (57% in mineral oil) are substantially freed of mineral oil by repeated washing with n-hexane and are then covered with a layer of 500 ml of dried tetrahydrofuran. Under a nitrogen atmosphere and while cooling in an ice bath, 134 g (0.6 mol) of phosphonoacetic acid triethyl ester of formula (H5C2O)2P(=O)CH2C(=O)OC2H5 are added dropwise thereto within a period of 1 hour. The mixture is stirred for a further 1 hour at 0°. To the homogeneous solution there is then added dropwise within a period of 30 minutes a solution of 88.57 g (0.5 mol) of 2,2-dimethyl-3-oxo-chroman [F. Camps et al., J. Heterocyclic Chem. 22, 1421 (1985)] in 300 ml of tetrahydrofuran. The mixture is stirred overnight at room temperature. The solution is then concentrated to approximately 350 ml in vacuo and poured onto 3 liters of ice-cold phosphate buffer solution (pH=6). The mixture is extracted with diethyl ether. The combined organic phases are washed with water and dried over sodium sulfate and then concentrated by evaporation in vacuo. The yellow residue is chromatographed on 4 kg of silica gel (0.040-0.063 mm) with toluene as eluant, yielding 60.3 g (49% of the theoretical yield) of 3-ethoxycarbonylmethyl-2,2-dimethyl-2H-chromene in the form of a light-yellow oil.

Workup

  1. washby repeated washing with n-hexane
  2. temperatureUnder a nitrogen atmosphere and while cooling in an ice bath
  3. stirringThe mixture is stirred overnight at room temperature
  4. concentrationThe solution is then concentrated to approximately 350 ml in vacuo
  5. additionpoured onto 3 liters of ice-cold phosphate buffer solution (pH=6)
  6. extractionThe mixture is extracted with diethyl ether
  7. washThe combined organic phases are washed with water
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated by evaporation in vacuo
  10. customThe yellow residue is chromatographed on 4 kg of silica gel (0.040-0.063 mm) with toluene as eluant
  11. customyielding 60.3 g (49% of the

Sources & evidence

ORD record
ord-257e1babbc00435d942e9eddf4f51894
Source dataset
uspto-grants-1992_05
Patent number
US05112855

Reaction notes

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