Carbon Dioxide → trichloroethyl N-benzylidene-alpha-amino-diethylphosphonoacetate

HRID 1658000Notes

Reaction equation

HRID 1658000 reaction equation
[CH:1](=[N:8][CH2:9][P:10](=[O:17])([O:14][CH2:15][CH3:16])[O:11][CH2:12][CH3:13])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C1([Li])C=CC=CC=1.[Cl:25][C:26]([Cl:33])([Cl:32])[CH2:27][O:28][C:29](Cl)=[O:30].C(=O)=O>O1CCCC1.C1C=CC=CC=1.C(OCC)C>[CH:1](=[N:8][CH:9]([P:10]([O:14][CH2:15][CH3:16])([O:11][CH2:12][CH3:13])=[O:17])[C:29]([O:28][CH2:27][C:26]([Cl:33])([Cl:32])[Cl:25])=[O:30])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 870632,2,2-Trichloroethyl chloroformateHCID 2773681N-(diethoxyphosphorylmethyl)-1-phenylmethanimineHCID 178506676HCID 178506676, compound

Product 1

HCID 54407468trichloroethyl N-benzylidene-alpha-amino-diethylphosphonoacetateYield 65.6%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 22174802Benzene etherSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of diethyl N-benzylidene-aminomethylphosphonate (12.738 g., 50 mmole) in dry tetrahydrofuran (250 ml.) is stirred in a dry ice-acetone bath and under a nitrogen atmosphere. Phenyllithium (25 ml. of a 2.0 M solution in 7:3 benzene-ethyl ether) is added via syringe. The resulting burgundy solution is stirred for 30 minutes at -78°C., then treated dropwise over 45 minutes with a solution of 2,2,2-trichloroethyoxycarbonyl chloride (5.30 g., 25 mmole) in dry tetrahydrofuran (50 ml.). After stirring the mixture for an additional 2 hours at -78°C., the dry ice bath is replaced by an ice water bath and stirring is continued for 1 hour. Evaporation of the solvent in vacuo leaves a yellow foam which is partitioned between ethyl ether (250 ml.) and aqueous phosphate (50 ml. of 1M pH 3 phosphate + 50 ml. water). The aqueous portion is separated and extracted with ethyl ether (2 × 50 ml.). The combined ethereal solution is washed with saturated brine (100 ml.), dried over magnesium sulfate, and evaporated in vacuo to yield a cloudy, yellow oil (17.1 g.). The crude product is purified by chromatography on silica gel (430 g., packed under ethyl ether). Elution with ethyl ether affords trichloroethyl N-benzylidene-α-amino-diethylphosphonoacetate (7.058 g.) as a yellow oil.

Workup

  1. stirringAfter stirring the mixture for an additional 2 hours at -78°C.
  2. stirringstirring
  3. waitis continued for 1 hour
  4. customEvaporation of the solvent in vacuo
  5. customleaves a yellow foam which
  6. customis partitioned between ethyl ether (250 ml.) and aqueous phosphate (50 ml. of 1M pH 3 phosphate + 50 ml. water)
  7. customThe aqueous portion is separated
  8. extractionextracted with ethyl ether (2 × 50 ml.)
  9. washThe combined ethereal solution is washed with saturated brine (100 ml.)
  10. dry with materialdried over magnesium sulfate
  11. customevaporated in vacuo
  12. customto yield a cloudy, yellow oil (17.1 g.)
  13. customThe crude product is purified by chromatography on silica gel (430 g., packed under ethyl ether)
  14. washElution with ethyl ether

Sources & evidence

ORD record
ord-9dfbb0f67d51430e9c3fe30d6804ec2d
Source dataset
uspto-grants-1976_06
Patent number
US03962224

Reaction notes

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