Phosphorus oxychloride → 3-chloro-1-(4-trifluoromethoxyphenyl)-4,5-dihydro-1H-pyrazole
Reaction equation
[F:1][C:2]([F:17])([F:16])[O:3][C:4]1[CH:9]=[CH:8][C:7]([N:10]2[CH2:14][CH2:13][C:12](=O)[NH:11]2)=[CH:6][CH:5]=1.P(Cl)(Cl)([Cl:20])=O>C1(C)C=CC=CC=1>[Cl:20][C:12]1[CH2:13][CH2:14][N:10]([C:7]2[CH:8]=[CH:9][C:4]([O:3][C:2]([F:17])([F:16])[F:1])=[CH:5][CH:6]=2)[N:11]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 80 °C
Procedure
The general procedure was taken from Wang et al. Tetrahedron Lett. 2005, 46, 2631. To a solution of 1-(4-trifluoromethoxyphenyl)-pyrazolidin-3-one (120 mg, 0.49 mmol, 1.00 eq) in toluene (20 mL) was slowly added phosphoryl chloride (22.5 mg, 1.47 mmol, 3.00 eq). The mixture was then heated at 80° C. for 1 h before cooling to room temperature and quenching with H2O (10 mL). The vessel was stirred under an atmosphere of nitrogen (N2) for 8 h before the product was extracted into EtOAc (200 mL), dried (MgSO4), and concentrated under reduced pressure. GC-MS proved 88% formation of the desired intermediate, which was used in subsequent reactions without further purification.
Workup
- temperaturebefore cooling to room temperature
- customquenching with H2O (10 mL)
- extractionwas extracted into EtOAc (200 mL)
- dry with materialdried (MgSO4)
- concentrationconcentrated under reduced pressure
- customGC-MS proved 88% formation of the desired intermediate, which was used in subsequent reactions without further purification
Sources & evidence
- ORD record
- ord-1a197223a0814890ab49b72604f48aa1
- Source dataset
- uspto-grants-2014_03
- Patent number
- US08680269B2
Reaction notes
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