Sulfuric Acid → (+/-)-(4R 5R*)-5-ethoxycarbonyl-1-methyl-4-(4-nitrophenyl)pyrrolidin-2-one
Reaction equation
[CH2:1]([O:3][C:4]([C@@H:6]1[N:10]([CH3:11])[C:9](=[O:12])[CH2:8][C@@H:7]1[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[O:5])[CH3:2].S(=O)(=O)(O)O.[N+:24]([O-])([O-:26])=[O:25].[K+]>>[CH2:1]([O:3][C:4]([C@@H:6]1[N:10]([CH3:11])[C:9](=[O:12])[CH2:8][C@@H:7]1[C:13]1[CH:14]=[CH:15][C:16]([N+:24]([O-:26])=[O:25])=[CH:17][CH:18]=1)=[O:5])[CH3:2]Participants
Procedure
To (±)-(4R*,5R*)-5-ethoxycarbonyl-1-methyl-4-phenyl-pyrrolidin-2-one (prepared according to the procedure of Intermediate T, Method 2, 1.00 g, 4.04 mmol) was added sulfuric acid (4.0 mL). To the resulting yellow solution was added potassium nitrate (0.50 g, 4.85 mmol) in portions, keeping the reaction temperature below 30° C. The reaction mixture was stirred for 18 h, then poured onto ice water (30 mL) and extracted with CH2Cl2, dried (MgSO4) and concentrated under reduced pressure. The oily residue was diluted with EtOAc and the resulting precipitate was collected by filtration. The solid was washed with Et2O to give (±)-(4R 5R*)-5-ethoxycarbonyl-1-methyl-4-(4-nitrophenyl)pyrrolidin-2-one (374 mg, 32%) as a white solid: mp 142-143° C.; TLC (33% EtOAc/hex) Rf 0.23; HPLC ES-MS m/z 293 (MH+).
Workup
- customthe reaction temperature below 30° C
- additionpoured onto ice water (30 mL)
- extractionextracted with CH2Cl2
- dry with materialdried (MgSO4)
- concentrationconcentrated under reduced pressure
- additionThe oily residue was diluted with EtOAc
- filtrationthe resulting precipitate was collected by filtration
- washThe solid was washed with Et2O
Sources & evidence
- ORD record
- ord-a7eb7bc6308849fdb9806928537a584c
- Source dataset
- uspto-grants-2004_08
- Patent number
- US06784167B2
Reaction notes
Loading…