Ammonium Chloride → 3-[2(R)-isopropyl-3(p-tert-butyl-phenyl)-propionyl]-4(R)-benzyl-oxazolidin-2-one

HRID 264888Notes

Reaction equation

HRID 264888 reaction equation
C[Si](C)(C)[N-][Si](C)(C)C.[Li+].[C:11]([N:17]1[C@H:21]([CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[CH2:20][O:19][C:18]1=[O:29])(=[O:16])[CH2:12][CH:13]([CH3:15])[CH3:14].[C:30]([C:34]1[CH:41]=[CH:40][C:37]([CH2:38]Br)=[CH:36][CH:35]=1)([CH3:33])([CH3:32])[CH3:31].[Cl-].[NH4+]>O1CCCC1>[CH:13]([C@@H:12]([CH2:38][C:37]1[CH:40]=[CH:41][C:34]([C:30]([CH3:33])([CH3:32])[CH3:31])=[CH:35][CH:36]=1)[C:11]([N:17]1[C@H:21]([CH2:22][C:23]2[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=2)[CH2:20][O:19][C:18]1=[O:29])=[O:16])([CH3:15])[CH3:14]

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 878361-(Bromomethyl)-4-(1,1-dimethylethyl)benzeneHCID 2733832Lithium HexamethyldisilazideHCID 11391340(4R)-4-Benzyl-3-(3-methylbutanoyl)-1,3-oxazolidin-2-one

Product 1

HCID 228657663-[2(R)-isopropyl-3(p-tert-butyl-phenyl)-propionyl]-4(R)-benzyl-oxazolidin-2-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
-70 °C

Procedure

30 ml of tetrahydrofuran are added to a solution of 31 ml of 1M lithium hexamethyldisilazide and the mixture is stirred at -70° C. A solution of 3-isovaleroyl-4(R)-benzyloxazolidin-2-one in 20 ml of tetrahydrofuran is then added dropwise thereto and the reaction mixture is stirred for a further 1 hour at -70° C. A solution of 9.6 g of p-tert-butyl-benzyl bromide in 20 ml of tetrahydrofuran is then added dropwise thereto and the reaction mixture is stirred for a further 1 hour at -25° C. and then for 4 hours at 0° C. 6 ml of saturated ammonium chloride solution are then added to the reaction mixture, which is freed of tetrahydrofuran by means of concentration and then subjected to extraction with diethyl ether. The extract is concentrated by evaporation and the residue is purified by FC (700 g of silica gel, eluant: dichloromethane/hexane=1:1), yielding the title compound: Rf (dichloromethane/hexane=1:1)=0.30; m.p.=123.5°-124° C.

Workup

  1. stirringthe reaction mixture is stirred for a further 1 hour at -70° C
  2. stirringthe reaction mixture is stirred for a further 1 hour at -25° C.
  3. concentrationis freed of tetrahydrofuran by means of concentration
  4. extractionsubjected to extraction with diethyl ether
  5. concentrationThe extract is concentrated by evaporation
  6. customthe residue is purified by FC (700 g of silica gel, eluant: dichloromethane/hexane=1:1)

Sources & evidence

ORD record
ord-84e27d7257ac41418466ddbc39223741
Source dataset
uspto-grants-1997_07
Patent number
US05646143

Reaction notes

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