Ethyl 2,4-dioxo-5-phenylpiperidine-3-carboxylate → 5-Phenylpiperidine-2,4-dione
Reaction equation
[O:1]=[C:2]1[CH:7](C(OCC)=O)[C:6](=[O:13])[CH:5]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH2:4][NH:3]1>C(#N)C.O>[C:14]1([CH:5]2[CH2:4][NH:3][C:2](=[O:1])[CH2:7][C:6]2=[O:13])[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
Sodium (380 mg, 16.52 mmol) was dissolved in anhydrous ethanol (13 mL) and the resulting solution was treated dropwise with 3-(2-ethoxycarbonyl-acetylamino)-2-phenyl-propionic acid ethyl ester (4.23 g, 13.76 mmol) dissolved in anhydrous toluene (35 mL). The reaction was kept at 80° C. for 1.5 hours. After cooling, the mixture was extracted with water. The aqueous extracts were acidified with 2 N HCl, extracted with ethyl acetate and the organic layers were collected, dried over Na2SO4 and evaporated to dryness to obtain ethyl 2,4-dioxo-5-phenylpiperidine-3-carboxylate (1.73 g, Y=48%) which was used for the next step without further purification. Ethyl 2,4-dioxo-5-phenylpiperidine-3-carboxylate (1.73 g, 6.63 mmol) was dissolved in acetonitrile containing 1% of water (30 mL) and the resulting solution was refluxed for 2 hours. After evaporating to dryness, the crude material was chromatographed on silica gel, eluting with methylene chloride/methanol 92/8, to give the title compound (780 mg, Y=62%) as a solid.
Workup
- customwas used for the next step without further purification
- temperaturethe resulting solution was refluxed for 2 hours
- customAfter evaporating to dryness
- customthe crude material was chromatographed on silica gel
- washeluting with methylene chloride/methanol 92/8
Sources & evidence
- ORD record
- ord-b5ba4f4a72c44fd69a6ba95c16ec37a7
- Source dataset
- uspto-grants-2007_10
- Patent number
- US07279575B2
Reaction notes
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