Hydrochloric Acid → 1-methyl-3-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid
Reaction equation
[CH3:1][N:2]1[CH:6]=[C:5]([C:7]([O:9]CC)=[O:8])[C:4]([C:12]([F:15])([F:14])[F:13])=[N:3]1.C1(C)C=CC=CC=1.[OH-].[Na+].Cl>O>[CH3:1][N:2]1[CH:6]=[C:5]([C:7]([OH:9])=[O:8])[C:4]([C:12]([F:13])([F:14])[F:15])=[N:3]1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 50 °C
Procedure
50 g of ethyl 1-methyl-3-trifluoromethyl-4-pyrazolecarboxylate were initially charged with 177 g of toluene and 54 g of 25% sodium hydroxide solution and heated to reflux for 15 hours. The cloudy reaction mixture was cooled to 50° C. and admixed with 69 g of water. The aqueous phase was adjusted to pH 1-2 at 30° C. by adding 83 g of 15% hydrochloric acid, and the product precipitated out of solution. The suspension was stirred for a further 30 minutes at room temperature and for 30 minutes at 0° C., and the crude product was then isolated and washed 3 times with 60 g each time of cold (<10° C.) water. After drying at room temperature and under reduced pressure, 43 g of 1-methyl-3-trifluoromethyl-4-pyrazolecarboxylic acid were obtained. This corresponds to a yield of 98% of theory.
Workup
- temperatureheated
- temperatureto reflux for 15 hours
- customThe cloudy reaction mixture
- customwas adjusted to pH 1-2 at 30° C.
- customthe product precipitated out of solution
- customthe crude product was then isolated
- washwashed 3 times with 60 g each time of cold (<10° C.) water
- customAfter drying at room temperature and under reduced pressure
Sources & evidence
- ORD record
- ord-768d08ef2f7f472a83947b43f7b993f8
- Source dataset
- uspto-grants-2004_03
- Patent number
- US06706911B1
Reaction notes
Loading…