3,4-dihydro-2H-pyran → 4-Bromo-5-methyl-1-(tetrahydro-pyran-2-yl)-3-trifluoromethyl-1H-pyrazole
Reaction equation
[Br:1][C:2]1[C:3]([C:8]([F:11])([F:10])[F:9])=[N:4][NH:5][C:6]=1[CH3:7].O.C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:24]1[CH:29]=[CH:28][CH2:27][CH2:26][CH2:25]1>C(Cl)(Cl)Cl>[Br:1][C:2]1[C:3]([C:8]([F:9])([F:11])[F:10])=[N:4][N:5]([CH:25]2[CH2:26][CH2:27][CH2:28][CH2:29][O:24]2)[C:6]=1[CH3:7]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
To a solution of 4-bromo-5-methyl-3-trifluoromethyl-1H-pyrazole (1.4 g, 6.2 mmol, 1.0 equiv) in chloroform (31 ml) was added p-toluene sulphonic acid monohydrate (118 mg, 0.62 mmol, 0.1 equiv). The solution was cooled to 0° C. and 3,4-dihydro-2H-pyran (0.85 ml, 9.3 mmol, 1.5 equiv) was added drop-wise over 5 minutes. The mixture was allowed to warm to room temperature for 1 hour and the solvents were removed under reduced pressure. The crude mixture was purified by column chromatography (SiO2), eluting with 0→25% EtOAc-petrol over a linear gradient to afford the title compound 1.4 g (59%), LCMS (PS-A) Rt 3.72 min [M+H]+ 314.
Workup
- temperatureto warm to room temperature for 1 hour
- customthe solvents were removed under reduced pressure
- customThe crude mixture was purified by column chromatography (SiO2)
- washeluting with 0→25% EtOAc-petrol over a linear gradient
Sources & evidence
- ORD record
- ord-fcc4e13ff5b04a86bd74ac0bdfe63f73
- Source dataset
- uspto-grants-2013_09
- Patent number
- US08541461B2
Reaction notes
Loading…