Hydrochloric Acid → (+)-Suprofen
Reaction equation
[CH3:1][O:2][C:3](=[O:19])[CH:4]([CH3:18])[C:5]1[CH:10]=[CH:9][C:8]([C:11]([C:13]2[S:14][CH:15]=[CH:16][CH:17]=2)=[O:12])=[CH:7][CH:6]=1.Cl>P([O-])([O-])([O-])=O>[CH3:1][O:2][C:3](=[O:19])[C@H:4]([CH3:18])[C:5]1[CH:6]=[CH:7][C:8]([C:11]([C:13]2[S:14][CH:15]=[CH:16][CH:17]=2)=[O:12])=[CH:9][CH:10]=1.[CH3:18][C@@H:4]([C:5]1[CH:10]=[CH:9][C:8]([C:11]([C:13]2[S:14][CH:15]=[CH:16][CH:17]=2)=[O:12])=[CH:7][CH:6]=1)[C:3]([OH:19])=[O:2]Participants
Reactant 2
Product 2
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 22 °C
Procedure
To 100 mg crude Candida cylindracea lipase (Sigma L1754 Type VII, 500 units/mg solid) in 4 mL 0.2 M phosphate buffer, pH 7.0, was added 200 mg (±)-α-methyl-4-(2-thienylcarbonyl)benzeneacetic acid methyl ester (suprofen methyl ester). The resulting suspension was gently stirred with a magnetic stirrer for 48 hours at 22° C. The reaction mixture was acidified to pH 1.0 with 1 N HCl and exhaustively extracted with ethyl acetate three times. The combined organic extract was dried over sodium sulfate and was then evaporated to dryness. The residue was chromatographed over a silica gel (MN Kieselgel 60) column (0.8×15 cm). Elution of the column with a solvent system consisting of ethyl acetate-hexane (1:5) gave unreacted (R)-α-methyl-4-(2-thienylcarbonyl)benzeneacetic acid methyl ester, [α]D25 =-54.7° (c=3.9, CHCl3), ee>0.90, and (S)-α-methyl-4-(2-thienylcarbonyl)benzeneacetic acid, [α]D25 =+43.5° (c=2.1, CHCl3), ee>0.95. The optical purity expressed as enantiomeric excess (ee) is determined by proton magnetic resonance spectroscopy of the methyl ester in the presence of the chiral lanthanide shift reagent, Eu(hfc)3.
Workup
- extractionexhaustively extracted with ethyl acetate three times
- extractionThe combined organic extract
- dry with materialwas dried over sodium sulfate
- customwas then evaporated to dryness
- customThe residue was chromatographed over a silica gel (MN Kieselgel 60) column (0.8×15 cm)
- washElution of the column with a solvent system
Sources & evidence
- ORD record
- ord-37117e28aa564e36b232f185bd7f5c3e
- Source dataset
- uspto-grants-1996_12
- Patent number
- US05587318
Reaction notes
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