Phosphorus oxychloride → HCID 19973430, compound

HRID 1452015Notes

Reaction equation

HRID 1452015 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[C:10]1[N:11]=[CH:12][C:13](=O)[NH:14][CH:15]=1.O=P(Cl)(Cl)[Cl:19]>>[Cl:19][C:13]1[CH:12]=[N:11][C:10]([C:3]2[CH:4]=[C:5]([O:8][CH3:9])[CH:6]=[CH:7][C:2]=2[F:1])=[CH:15][N:14]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 53820982HCID 53820982, compound

Product 1

HCID 19973430HCID 19973430, compound

Procedure

A solution of 5-(2-fluoro-5-methoxyphenyl)-pyrazin-2-one in POCl3 was heated at 100° C. -110° C. in a sealed tube for 16 h. After evaporating the remaining POCl3 under reduced pressure, the brown residue was taken up in EtOAc and washed (3×) with saturated aqueous NaHCO3 solution. The EtOAc solution was then dried (NA2SO4) and concentrated under reduced pressure leaving a brown oil. The oil was filtered through a pad of silica gel (30% EtOAc/hexanes eluent) and the solvents were again evaporated under reduced pressure. The oil was taken up in CH2Cl2, heated for 5 min, with decolorizing charcoal and filtered through celite. Evaporation of the solvent afforded 2-chloro-5-(2-fluoro-5-methoxyphenyl)pyrazine as a light-brown oil.

Workup

  1. customAfter evaporating the remaining POCl3 under reduced pressure
  2. washwashed (3×) with saturated aqueous NaHCO3 solution
  3. dry with materialThe EtOAc solution was then dried (NA2SO4)
  4. concentrationconcentrated under reduced pressure
  5. customleaving a brown oil
  6. filtrationThe oil was filtered through a pad of silica gel (30% EtOAc/hexanes eluent)
  7. customthe solvents were again evaporated under reduced pressure
  8. temperatureheated for 5 min, with decolorizing charcoal
  9. filtrationfiltered through celite
  10. customEvaporation of the solvent

Sources & evidence

ORD record
ord-cfb9a8c2e2a744c5a83e55e9254c3981
Source dataset
uspto-grants-1997_02
Patent number
US05606059

Reaction notes

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