Methylhydrazine → Ethyl 3-difluoromethyl-1-methyl-4-pyrazole carboxylate

HRID 547968Notes

Reaction equation

HRID 547968 reaction equation
F[C:2]([N:7](C)C)(F)[CH:3]([F:5])[F:4].B(F)(F)F.CN([C:17](=[CH2:23])[C:18]([O:20][CH2:21][CH3:22])=[O:19])C.[CH3:24][NH:25]N>C(#N)C>[F:5][CH:3]([F:4])[C:2]1[C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[CH:23][N:25]([CH3:24])[N:7]=1

Participants

6

Reactant 4

HCID 6061MethylhydrazineHCID 6356Boron trifluorideHCID 10103284HCID 10103284, compoundHCID 21945697Ethanamine, 1,1,2,2-tetrafluoro-N,N-dimethyl-

Product 1

HCID 11644126Ethyl 3-difluoromethyl-1-methyl-4-pyrazole carboxylateYield 80.9%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent3×

Procedure

10.8 g of N-1,1,2,2-tetrafluoroethyldimethylamine were initially charged in 50 ml of acetonitrile under argon and 26 g of boron trifluoride as a 17% solution in CH3CN were added at RT. The mixture was stirred for 30 min and then admixed with 8.67 g of ethyl dimethylaminoacrylate. The mixture was stirred at RT for 2 h and then added slowly to the solution of 3.4 g of methylhydrazine in 10 ml of acetonitrile at 10° C. After stirring at RT for 2 h, the acetonitrile was removed completely under reduced pressure and the product was admixed with water and filtered off. Distillation under reduced pressure or washing with cyclohexane afforded 10 g of the product with the purity of 99% and an m.p. of 62-63° C.

Workup

  1. stirringThe mixture was stirred at RT for 2 h
  2. stirringAfter stirring at RT for 2 h
  3. customthe acetonitrile was removed completely under reduced pressure
  4. filtrationfiltered off
  5. distillationDistillation under reduced pressure
  6. washwashing with cyclohexane

Sources & evidence

ORD record
ord-59bffec6e2ec4b758a5caaa65d47ea30
Source dataset
uspto-grants-2011_05
Patent number
US07939673B2

Reaction notes

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