Bromine → 4-bromo-3-(difluoromethyl)-5-methyl-1H-pyrazole
Reaction equation
[F:1][CH:2]([F:10])[C:3]1(O)[NH:7][N:6]=[C:5]([CH3:8])[CH2:4]1.[Br:11]Br>C(Cl)Cl>[Br:11][C:4]1[C:3]([CH:2]([F:10])[F:1])=[N:7][NH:6][C:5]=1[CH3:8]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 25 °C
Procedure
To a solution of 5-(difluoromethyl)-3-methyl-4,5-dihydro-1H-pyrazol-5-ol (1.00 g, 6.66 mmol) in methylene chloride (20 mL) was added bromine (0.43 mL, 8.3 mmol) dropwise. The reaction was stirred at 25° C. for 3 h. and then quenched with a Na2S2O4 solution and neutralized with NaHCO3. The reaction was extracted with dichloromethane and the organic extracts were washed with water, brine, dried (MgSO4), and concentrated in vacuo. 1H NMR (CDCl3): δ 6.56-6.82 (t, 1H), 2.33 (s, 3H). Mass spec(EI) m/z=211&213 (M+1).
Workup
- customquenched with a Na2S2O4 solution
- extractionThe reaction was extracted with dichloromethane
- washthe organic extracts were washed with water, brine
- dry with materialdried (MgSO4)
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-a269b9d4ca5b4da5b06a091fbfb7415d
- Source dataset
- uspto-grants-2014_09
- Patent number
- US08835423B2
Reaction notes
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