Hydrochloric Acid → Bis(2,4-dichlorophenyl) phosphorochloridate

HRID 330057Notes

Reaction equation

HRID 330057 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[OH:9].[P:10]([Cl:14])(Cl)(Cl)=[O:11].[ClH:15].[OH-:16].[Na+]>CN(C)C1C=CN=CC=1>[P:10]([Cl:14])(=[O:11])([O:16][C:3]1[CH:4]=[CH:5][C:6]([Cl:15])=[CH:7][C:2]=1[Cl:1])[O:9][C:3]1[CH:4]=[CH:5][C:6]([Cl:8])=[CH:7][C:2]=1[Cl:1]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 84492,4-DichlorophenolHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychloride

Product 1

HCID 5012072Bis(2,4-dichlorophenyl) phosphorochloridateYield 26%

Reagents, catalysts & solvents 1

HCID 142844-(Dimethylamino)pyridineCatalyst

Procedure

To a melt of 2,4-dichlorophenol (400.0 g, 2.454 mole) at ca. 50° was added 4-dimethylamino-pyridine (6.93 g, 56 mmole), followed by phosphorus oxychloride (289.5 g, 1.887 mole). The mixture was heated under nitrogen to ca. 120°, at which temperature the mixture began to reflux and to generate hydrogen chloride (which was passed through a sodium hydroxide scrubber). After about twelve hours at 120°-125°, gas-liquid partition chromatography (GLPC) using a silica capillary indicated less than 1% (by weight) of unreacted 2,4-dichlorophenol and a mixture of 2,4-dichlorophenyl phosphorodichloridate, the desired bis(2,4-dichlorophenyl) phosphorochloridate, and tris(2,4-dichlorophenyl) phosphate. After the reaction mixture was cooled to ca. 40°, hexane (145 ml) was added and the mixture was cooled to ca. 20°. A precipitate containing 4-dimethylaminopyridine hydrochloride was removed by filtration. The filtrate was diluted with additional hexane (145 ml) and cooled to ca. -30°. After about eight hours the resultant precipitate was collected by filtration and washed with hexane (four 200-ml portions) at ca. -20°, all with careful exclusion of moisture. Drying for two hours at room temperature under a flow of nitrogen yielded 129.87 g (26% yield) of the desired bis(2,4-dichlorophenyl) phosphorochloridate as a white solid. Analysis by GLPC indicated 99% purity (by weight), with contamination by 0.3% (by weight) 2,4-dichlorophenyl phosphorodichloridate and 0.2% (by weight) tris(2,4-dichlorophenyl) phosphate.

Workup

  1. temperatureThe mixture was heated under nitrogen to ca. 120°, at which temperature the mixture
  2. temperatureto reflux
  3. waitAfter about twelve hours at 120°-125°
  4. customgas-liquid partition chromatography (GLPC)
  5. additiona mixture of 2,4-dichlorophenyl phosphorodichloridate
  6. temperatureAfter the reaction mixture was cooled to ca. 40°
  7. additionhexane (145 ml) was added
  8. temperaturethe mixture was cooled to ca. 20°
  9. additionA precipitate containing 4-dimethylaminopyridine hydrochloride
  10. customwas removed by filtration
  11. additionThe filtrate was diluted with additional hexane (145 ml)
  12. temperaturecooled to ca. -30°
  13. filtrationAfter about eight hours the resultant precipitate was collected by filtration
  14. washwashed with hexane (four 200-ml portions) at ca. -20°
  15. customDrying for two hours at room temperature under a flow of nitrogen

Sources & evidence

ORD record
ord-858b06dcc9f34f92b7f93ef7327249dd
Source dataset
uspto-grants-1990_01
Patent number
US04894450

Reaction notes

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