(4-Fluorophenyl)dimethylphosphine oxide → 1-(Dimethyl-phosphinoyl)-4-nitro-benzene

HRID 1061503Notes

Reaction equation

HRID 1061503 reaction equation
[CH3:1][P:2]([CH3:11])([C:4]1[CH:9]=[CH:8][C:7](F)=[CH:6][CH:5]=1)=[O:3].[Li][N+:13]([O-:15])=[O:14]>CN1C(=O)N(C)CCC1.[Cl-].[Na+].O.CC(O)C>[CH3:1][P:2]([CH3:11])([C:4]1[CH:9]=[CH:8][C:7]([N+:13]([O-:15])=[O:14])=[CH:6][CH:5]=1)=[O:3]

Participants

6

Reactant 2

HCID 21897903(4-Fluorophenyl)dimethylphosphine oxideHCID 178506934HCID 178506934, compound

Product 1

HCID 218979121-(Dimethyl-phosphinoyl)-4-nitro-benzeneYield 45.1%

Reagents, catalysts & solvents 3

HCID 3776IsopropanolSolventHCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-SolventHCID 57417360Sodium chloride; waterSolvent

Procedure

A sealed pressure flask, flushed with N2, containing a mixture of 3.90 g (22.7 mmol) of 1-(Dimethyl-phosphinoyl)-4-fluoro-benzene and 6.0 g (113.3 mmol) of LiNO2 (for prep see, W. C. Ball and H. H. Abram J. Chem. Soc. 1913, 103, 2130-2134) in 27 mL of DMPU (1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone) was stirred at ambient temperature for 5-10 min (to dissolve fluoro compound) then heated at 190° C. for 3 days. The resulting dark brown solution was cooled to ambient temperature, diluted with 300 mL of brine, then extracted with EtOAc (10×100 mL) until the aqueous layer showed little or no evidence of product by HPLC. The combined organics were dried over MgSO4 and concentrated. The excess DMPU was removed via short-path distillation (120° C./0.3 mm) to provide a semi-solid, which was dissolved in a minimum amount of iPrOH and purified by silica gel flash chromatography (eluted with 5% iPrOH/DCM, then 10% iPrOH/DCM, then 15% iPrOH/DCM) to provide 2.04 g of an yellow solid: 1H NMR (300 MHz, DMSO-d6) δ 8.34 (dd, J=8.7, 1.9 Hz, 2H), 8.07 (dd, J=10.6, 8.8 Hz, 2H), 1.75 (s, 3H), 1.70 (s, 3H). 31P NMR (121 MHz, DMSO-d6) δ 37.89.

Workup

  1. customA sealed pressure flask, flushed with N2
  2. additioncontaining
  3. temperaturethen heated at 190° C. for 3 days
  4. temperatureThe resulting dark brown solution was cooled to ambient temperature
  5. extractionextracted with EtOAc (10×100 mL) until the aqueous layer
  6. dry with materialThe combined organics were dried over MgSO4
  7. concentrationconcentrated
  8. customThe excess DMPU was removed via short-path distillation (120° C./0.3 mm)
  9. customto provide a semi-solid, which
  10. custompurified by silica gel flash chromatography (
  11. washeluted with 5% iPrOH/DCM

Sources & evidence

ORD record
ord-fa19f0cc6ee440828c727181eaf57485
Source dataset
uspto-grants-2005_11
Patent number
US06960572B2

Reaction notes

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