Hydrochloric Acid → 1-Methyl-3-(trifluoromethyl)-4,5-dihydro-1H-pyrazole-4-carboxylic acid

HRID 1674484Notes

Reaction equation

HRID 1674484 reaction equation
C([O:3][C:4]([CH:6]1[CH2:10][N:9]([CH3:11])[N:8]=[C:7]1[C:12]([F:15])([F:14])[F:13])=[O:5])C.[OH-].[Na+].Cl>O1CCOCC1>[CH3:11][N:9]1[CH2:10][CH:6]([C:4]([OH:5])=[O:3])[C:7]([C:12]([F:13])([F:14])[F:15])=[N:8]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 67339313HCID 67339313, compound

Product 1

HCID 673400881-Methyl-3-(trifluoromethyl)-4,5-dihydro-1H-pyrazole-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

1-Methyl-3-trifluoromethyl-4,5-dihydro-1H-pyrazole-4-carboxylic acid ethyl ester (20 g, 90 mmol) was dissolved in 400 ml of dioxan. 400 ml of a 1 N aqueous sodium hydroxide solution (0.4 mol) were added and the reaction mixture was stirred for 2 h at room temperature. Subsequently the mixture was acidified with concentrated hydrochloric acid (pH 2). The dioxan was removed in vacuo, the residue was extracted with ethyl acetate. The combined organic layer was washed with brine, dried over magnesium sulfate and evaporated, delivering 15 g of 1-methyl-3-trifluoromethyl-4,5-dihydro-1H-pyrazole-4-carboxylic acid, which could be directly used in the next step without further purification.

Workup

  1. customThe dioxan was removed in vacuo
  2. extractionthe residue was extracted with ethyl acetate
  3. washThe combined organic layer was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. customevaporated
  6. customcould be directly used in the next step without further purification

Sources & evidence

ORD record
ord-a327e625aeff4945842a4b7e3be99e29
Source dataset
uspto-grants-2011_08
Patent number
US08003626B2

Reaction notes

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