Methylhydrazine → 1,5-Dimethyl-3-(trifluoromethyl)pyrazole

HRID 1031330Notes

Reaction equation

HRID 1031330 reaction equation
[F:1][C:2]([F:10])([F:9])[C:3]([CH2:5][C:6](=O)[CH3:7])=O.[CH3:11][NH:12][NH2:13]>>[CH3:11][N:12]1[C:6]([CH3:7])=[CH:5][C:3]([C:2]([F:10])([F:9])[F:1])=[N:13]1

Participants

3

Reactant 2

HCID 6061MethylhydrazineHCID 739431,1,1-Trifluoro-2,4-pentanedione

Product 1

HCID 127475251,5-Dimethyl-3-(trifluoromethyl)pyrazoleYield 73.1%

Procedure

Into 100 ml of an ethanolic solution of 25 g (0.16 mol) of trifluoroacetylacetone, there was added dropwise 7.4 g (0.16 mol) of methylhydrazine. After stirring at room temperature for 3 hours, the mixture was left to stand overnight and the solvent was evaporated to give 19.2 g of 1,5-dimethyl-3-trifluoromethylpyrazole as an oil. Following then the procedures as Reference example 1, this product was allowed to react with chlorosulfonic acid and then with thionyl chloride to obtain 29 g of 1,5-dimethyl-3-trifluoromethylpyrazole-4-sulfonyl-chloride, which was in turn reacted with aqueous ammonia (28%) in tetrahydrofuran to give 21.5 g of 1,5-dimethyl-3-trifluoromethylpyrazole-4-sulfonamide melting at 204°-206° C.

Workup

  1. waitthe mixture was left
  2. waitto stand overnight
  3. customthe solvent was evaporated

Sources & evidence

ORD record
ord-82df310679c44d6fbd41b120dbd004c2
Source dataset
uspto-grants-1990_09
Patent number
US04954164

Reaction notes

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