Dimethylformamide → 3-Chloro-6-(4-fluorophenyl)-1,2,4-triazine

HRID 237096Notes

Reaction equation

HRID 237096 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[N:10][C:11](=O)[NH:12][N:13]=2)=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:17])=O.CN(C)C=O>C(Cl)(Cl)Cl>[Cl:17][C:11]1[N:12]=[N:13][C:8]([C:5]2[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=2)=[CH:9][N:10]=1

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 125812846-(4-Fluorophenyl)-1,2,4-triazin-3(2H)-one

Product 1

HCID 213152193-Chloro-6-(4-fluorophenyl)-1,2,4-triazine

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

A suspension of 20 g. of 6-(p-fluorophenyl)-1,2,4-triazin-3(2H)-one in 158 ml. of chloroform is cooled in an ice bath and 178.5 ml. of phosphorus oxychloride is added followed by 1.2 g. of N,N-dimethylformamide. The mixture is refluxed for 4.5 hours and then the excess phosphorus oxychloride is removed in vacuo. The residue is redissolved in chloroform and poured into ice-water. When the ice melts the mixture is filtered. The organic layer of the filtrate is washed with water and saturated sodium bicarbonate solution and then dried giving a brown semi-solid. This semi-solid is taken up in chloroform and filtered through a short silica gel column giving 3-chloro-6-(p-fluorophenyl)-1,2,4-triazine as a tan solid.

Workup

  1. additionA suspension of 20 g
  2. temperatureThe mixture is refluxed for 4.5 hours
  3. customthe excess phosphorus oxychloride is removed in vacuo
  4. dissolutionThe residue is redissolved in chloroform
  5. additionpoured into ice-water
  6. filtrationis filtered
  7. washThe organic layer of the filtrate is washed with water and saturated sodium bicarbonate solution
  8. customdried
  9. customgiving a brown semi-solid
  10. filtrationfiltered through a short silica gel column

Sources & evidence

ORD record
ord-8dbc5eccf14a48839b7b4cedc5fb0853
Source dataset
uspto-grants-1979_06
Patent number
US04159375

Reaction notes

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