Dimethylformamide → 1-[3-(Trifluoromethyl)phenyl]-1H-pyrazole-4-carbaldehyde

HRID 27279Notes

Reaction equation

HRID 27279 reaction equation
P(Cl)(Cl)(Cl)=O.[F:6][C:7]([F:20])([F:19])[C:8]1[CH:9]=[C:10]([N:14]2[CH:18]=[CH:17][CH:16]=[N:15]2)[CH:11]=[CH:12][CH:13]=1.CN(C)[CH:23]=[O:24]>>[F:20][C:7]([F:6])([F:19])[C:8]1[CH:9]=[C:10]([N:14]2[CH:18]=[C:17]([CH:23]=[O:24])[CH:16]=[N:15]2)[CH:11]=[CH:12][CH:13]=1

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 130663261-(3-(trifluoromethyl)phenyl)-1H-pyrazole

Product 1

HCID 233444471-[3-(Trifluoromethyl)phenyl]-1H-pyrazole-4-carbaldehydeYield 57%

Conditions

Temperature
100 °C

Procedure

Into a 500 ml., 2-neck flask, fitted with a condenser and a magnetic stirrer, containing 60.5 ml. (0.78 M.) of absolute dimethylformamide (dried over 3A sieves) is slowly added, while the temperature is maintained at less than 10° C., 36.9 ml. (0.39 M.) of phosphorus oxychloride, after which time the reaction mixture is allowed to stand at room temperature until a bright red color develops (typically, between 30 and 60 minutes). To the resultant reaction mixture is then added 23.2 g. (0.109 M.) of 1-(m-trifluoromethylphenyl)-pyrazole, while the temperature is maintained at between 50° and 70° C. The reaction mixture is then slowly heated to 100° C. and allowed to stand overnight, while the temperature is maintained at 100° C. The reaction mixture is then cooled, quenched in ice water and allowed to stand overnight at room temperature. The resultant precipitated solids are then filtered and washed successively with water and petroleum ether. The solvent is then removed under vacuum to yield 1-(m-trifluoromethylphenyl)pyrazole-4-carboxaldehyde (Yield: 57%). A second crop was also obtained, m.p. 80°-82° C. (Yield: 63%).

Workup

  1. custom, 2-neck flask, fitted with a condenser and a magnetic stirrer
  2. additioncontaining 60.5 ml
  3. temperatureis maintained at less than 10° C.
  4. customto stand at room temperature until a bright red color
  5. custombetween 30 and 60 minutes
  6. customTo the resultant reaction mixture
  7. additionis then added 23.2 g
  8. temperatureis maintained at 100° C
  9. temperatureThe reaction mixture is then cooled
  10. customquenched in ice water
  11. waitto stand overnight at room temperature
  12. customThe resultant precipitated solids
  13. filtrationare then filtered
  14. washwashed successively with water and petroleum ether
  15. customThe solvent is then removed under vacuum

Sources & evidence

ORD record
ord-12765d1860714e14ae148f61119ebd48
Source dataset
uspto-grants-1980_09
Patent number
US04220792

Reaction notes

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