Citric Acid → (2S)-2-phenyl-3-piperidone
Reaction equation
CS(C)=O.C(Cl)(=O)C(Cl)=O.[OH:11][C@H:12]1[CH2:17][CH2:16][CH2:15][NH:14][C@H:13]1[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.C(N(CC)CC)C.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>ClCCl>[C:18]1([C@H:13]2[C:12](=[O:11])[CH2:17][CH2:16][CH2:15][NH:14]2)[CH:19]=[CH:20][CH:21]=[CH:22][CH:23]=1Participants
Conditions
- Temperature
- -10 °C
Procedure
A solution of dimethyl sulfoxide (4.2 ml, 59 mmol) in dichloromethane (10 ml) was added dropwise to a stirred solution of oxalyl chloride ( 4.4 ml, 51 mmol) in dichloromethane (100 ml) at −70° C. over 10 min. After 10 min a solution of (2S,3S)-3-hydroxy-2-phenylpiperidine (10.5 g, 38.5 mmol) in dichloromethane (30 ml) was added dropwise at −70° C. over 10 min. The mixture was stirred an additional 10 min and triethylamine (15 ml, 108 mmol) added dropwise over 15 min. The reaction mixture was allowed to warm to −10° C. over 90 min and poured into a 10% aqueous solution of citric acid (200 ml). The phases were separated and the aqueous layer was extracted with dichloromethane (2×50 ml). The combined organic extracts were dried (Na2SO4) and concentrated to give crude (2S)-2-phenyl-3-piperidone which was immediately used in the next step.
Workup
- customThe phases were separated
- extractionthe aqueous layer was extracted with dichloromethane (2×50 ml)
- dry with materialThe combined organic extracts were dried (Na2SO4)
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-9dc1b8c68fd64001b20b29754297e110
- Source dataset
- uspto-grants-2001_05
- Patent number
- US06225320B1
Reaction notes
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