Methanesulfonic Acid → Ethyl 3-difluoromethyl-1-methyl-4-pyrazole carboxylate

HRID 1042958Notes

Reaction equation

HRID 1042958 reaction equation
[F:1][CH:2]([F:14])[C:3]1[N:7](C)[N:6]=[CH:5][C:4]=1[C:9]([O:11][CH2:12][CH3:13])=[O:10].P([O-])(OC)O[CH3:17].CS(O)(=O)=O>>[F:1][CH:2]([F:14])[C:3]1[C:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])=[CH:5][N:6]([CH3:17])[N:7]=1

Participants

4

Reactant 3

HCID 6395Methanesulfonic AcidHCID 21884954DimethylphosphiteHCID 45933751Ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate

Product 1

HCID 11644126Ethyl 3-difluoromethyl-1-methyl-4-pyrazole carboxylateYield 69.1%

Conditions

Temperature
170 °C

Procedure

To 20.4 g of ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (iso-DFPE) was added 11.3 g of dimethyl phosphite and 0.82 g of methane sulfonic acid. The mixture was heated to 170° C. and stirred for 7 hours. The solution was cooled and distilled to recover recycled trimethyl phosphate and 0.9 g of starting ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (iso-DFPE). The remaining solution was added to 50 g of cold water. The solution was allowed to stir for 30 min. The precipitating solid was filtered and dried to give 14.1 g of product.

Workup

  1. temperatureThe solution was cooled
  2. distillationdistilled
  3. customto recover recycled trimethyl phosphate and 0.9 g of starting ethyl 5-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate (iso-DFPE)
  4. additionThe remaining solution was added to 50 g of cold water
  5. stirringto stir for 30 min
  6. filtrationThe precipitating solid was filtered
  7. customdried

Sources & evidence

ORD record
ord-1be5f7fbe9ba40948c770f66502e1907
Source dataset
uspto-grants-2013_10
Patent number
US08558006B2

Reaction notes

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