(S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-oxopropyl)-6-phenyl-1,3-oxazinan-2-one → (S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-hydroxy-2-methylpropyl)-6-phenyl-1,3-oxazinan-2-one

HRID 1640718Notes

Reaction equation

HRID 1640718 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C@@H:8]([N:10]2[CH2:15][CH2:14][C@:13]([CH2:22][C:23](=[O:25])[CH3:24])([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)[O:12][C:11]2=[O:26])[CH3:9])=[CH:4][CH:3]=1.[CH3:27][Mg]Br>C1COCC1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C@@H:8]([N:10]2[CH2:15][CH2:14][C@:13]([CH2:22][C:23]([OH:25])([CH3:27])[CH3:24])([C:16]3[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=3)[O:12][C:11]2=[O:26])[CH3:9])=[CH:4][CH:3]=1

Participants

4

Procedure

To a solution of (S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-oxopropyl)-6-phenyl -1,3-oxazinan-2-one (20 g, 46.4 mmol) in anhydrous THF (200 mL) was added dropwise methylmagnesium bromide (31 mL, 144 mmol) at −78° C. under nitrogen. Then the mixture was stirred at rt for 1 h. The reaction mixture was quenched with aq NaHCO3 (50 mL) under ice water bath. The organic layers were separated. The aqueous layer was extracted with EtOAc (150 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo to give the crude product, which was purified column chromatography (petroleum ether/EtOAc=5:1 to 2:1) to afford (S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-hydroxy-2-methylpropyl) -6-phenyl-1,3-oxazinan-2-one (13 g, 65%). After re-crystallization from EtOH, 4 g of the pure compound was obtained. 1H NMR (CDCl3): 1.06 (s, 3H), 1.12 (s, 3H), 1.44 (d, 3H), 2.14 (m, 3H), 2.21 (m, 1H), 2.33 (m, 1H), 2.76 (m, 1H), 5.54 (q, 1H), 6.74 (d, 2H), 7.16 (d, 2H), 7.28 (m, 5H).

Workup

  1. customThe reaction mixture was quenched with aq NaHCO3 (50 mL) under ice water bath
  2. customThe organic layers were separated
  3. extractionThe aqueous layer was extracted with EtOAc (150 mL)
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated in vacuo
  7. customto give the crude product, which
  8. customwas purified column chromatography (petroleum ether/EtOAc=5:1 to 2:1)

Sources & evidence

ORD record
ord-f2fd8a47f5f5405bbd4196f776a321fa
Source dataset
uspto-grants-2012_02
Patent number
US08114868B2

Reaction notes

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