Sodium Carbonate → Pyrifenox

HRID 364625Notes

Reaction equation

HRID 364625 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9](=O)[CH2:10][C:11]1[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=1.C(=O)([O-])[O-].[Na+].[Na+].Cl.[CH3:25][O:26][NH2:27]>C(O)C>[CH3:25][O:26][N:27]=[C:9]([C:3]1[CH:4]=[CH:5][C:6]([Cl:8])=[CH:7][C:2]=1[Cl:1])[CH2:10][C:11]1[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=1

Participants

5

Reactant 3

HCID 10340Sodium CarbonateHCID 521874O-Methylhydroxylamine hydrochlorideHCID 13488634Ethanone, 1-(2,4-dichlorophenyl)-2-(3-pyridinyl)-

Product 1

HCID 55790Pyrifenox

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 13.3 g of 2',4'-dichloro-2-(3-pyridyl)-acetophenone in 40 ml of ethanol is treated with 10 g of sodium carbonate and 8.3 g of O-methylhydroxylamine hydrochloride; the mixture is subsequently heated at reflux temperature while stirring. After 4 hours, the mixture is poured onto ice and extracted with ethyl acetate. The organic phase is washed, dried over sodium sulfate and concentrated under reduced pressure to yield 2',4'-dichloro-2-(3-pyridyl)-acetophenone O-methyl oxime as the E,Z-isomer mixture in the form of a yellowish oil. Chromatographic separation on silica gel with n-hexane/ethyl acetate (4:1) as the eluant yields firstly the E-isomer (nD20 =1.5845) and then the Z-isomer (nD20 =1.5745).

Workup

  1. temperaturethe mixture is subsequently heated
  2. temperatureat reflux temperature
  3. additionthe mixture is poured onto ice
  4. extractionextracted with ethyl acetate
  5. washThe organic phase is washed
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-24f7328b38a9477b8190cf0bedf1244a
Source dataset
uspto-grants-1986_08
Patent number
US04605656

Reaction notes

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