Cerium(III) chloride → 4-Benzyl-5-(2-tert-butylcarbamoyl-4-hydroxy-cyclohexylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

HRID 987920

Reaction equation

HRID 987920 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH:12]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH:11]([CH2:20][CH:21]2[CH2:26][CH2:25][C:24](=[O:27])[CH2:23][CH:22]2[C:28](=[O:34])[NH:29][C:30]([CH3:33])([CH3:32])[CH3:31])[O:10][C:9]1([CH3:36])[CH3:35])=[O:7])([CH3:4])([CH3:3])[CH3:2].[Cl-].[Ce+3].[Cl-].[Cl-].[BH4-].[Na+]>CO>[C:1]([O:5][C:6]([N:8]1[CH:12]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH:11]([CH2:20][CH:21]2[CH2:26][CH2:25][CH:24]([OH:27])[CH2:23][CH:22]2[C:28](=[O:34])[NH:29][C:30]([CH3:33])([CH3:32])[CH3:31])[O:10][C:9]1([CH3:36])[CH3:35])=[O:7])([CH3:3])([CH3:4])[CH3:2]

Participants

5

Reactant 3

HCID 24636Cerium(III) chlorideHCID 4311764Sodium borohydrideHCID 698540804-Benzyl-5-(2-tert-butylcarbamoyl-4-oxo-cyclohexylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

Product 1

HCID 698547824-Benzyl-5-(2-tert-butylcarbamoyl-4-hydroxy-cyclohexylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl esterYield 77.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 4-benzyl-5-(2-tert-butylcarbamoyl-4-oxo-cyclohexylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (1.1 g, 2.2 mmol) in dry methanol (20 ml) was stirred at room temperature under nitrogen during the addition of cerium chloride (1.8 g, 4.84 mmol). The resulting mixture was stirred at room temperature for 30 minutes, then cooled to −78° C. and treated with sodium borohydride (183 mg, 4.84 mmol). The resulting suspension was allowed to warm to 0° C. over 90 min, then partitioned between ethyl acetate and a mixture of saturated aqueous ammonium chloride solution and brine. The two layers were separated and the aqueous phase was extracted twice with ethyl acetate. The combined organic layers were dried (anhydrous magnesium sulfate) and concentrated in vacuo. Purification by flash chromatography on silica gel (ethyl acetate/hexane: 1/1 to 2/1) provided 4-benzyl-5-(2-tert-butylcarbamoyl-4-hydroxy-cyclohexylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (860 mg).

Workup

  1. temperaturecooled to −78° C.
  2. temperatureto warm to 0° C. over 90 min
  3. custompartitioned between ethyl acetate
  4. additiona mixture of saturated aqueous ammonium chloride solution and brine
  5. customThe two layers were separated
  6. extractionthe aqueous phase was extracted twice with ethyl acetate
  7. dry with materialThe combined organic layers were dried (anhydrous magnesium sulfate)
  8. concentrationconcentrated in vacuo
  9. customPurification by flash chromatography on silica gel (ethyl acetate/hexane: 1/1 to 2/1)

Sources & evidence

ORD record
ord-8d2d03d10be3438e94fcce368d028557
Source dataset
uspto-grants-2003_10
Patent number
US06632826B1

Linked notes

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