Sodium hydride → (S)-methyl 3,4-dihydro-2,8-diisopropyl-3-oxo-2H-1,4-benzoxazine-4-acetate

HRID 622370Notes

Reaction equation

HRID 622370 reaction equation
[CH:1]([C@H:4]1[C:9](=[O:10])[NH:8][C:7]2[CH:11]=[CH:12][CH:13]=[C:14]([CH:15]([CH3:17])[CH3:16])[C:6]=2[O:5]1)([CH3:3])[CH3:2].[H-].[Na+].Br[CH2:21][C:22]([O:24][CH3:25])=[O:23]>CN(C)C=O.O>[CH:1]([C@H:4]1[C:9](=[O:10])[N:8]([CH2:21][C:22]([O:24][CH3:25])=[O:23])[C:7]2[CH:11]=[CH:12][CH:13]=[C:14]([CH:15]([CH3:17])[CH3:16])[C:6]=2[O:5]1)([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 24758Sodium hydrideHCID 60984Methyl bromoacetateHCID 7210282(S)-2,8-diisopropyl-2H-1,4-benzoxazin-3(4H)-one

Product 1

HCID 14234720(S)-methyl 3,4-dihydro-2,8-diisopropyl-3-oxo-2H-1,4-benzoxazine-4-acetateYield 81.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent2×

Procedure

To a solution of (S)-2,8-diisopropyl-2H-1,4-benzoxazin-3(4H)-one (4.66 g) in dimethylformamide (60 ml), was added portionwise 60% sodium hydride in oil (0.84 g). The mixture was stirred at room temperature for 10 minutes, and a solution of methyl bromoacetate (2.0 ml) in dimethylformamide (6.0 ml) was added thereto. The whole was stirred at room temperature for 30 minutes, diluted with water, and extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4) and concentrated. The residue was crystallized from hexane to yield (S)-methyl 3,4-dihydro-2,8-diisopropyl-3-oxo-2H-1,4-benzoxazine-4-acetate as crystals (4.95 g, 81.1%). Recrystallization from hexane gave colorless needles, mp 67°-68° C. [α]D23 +3.7° (c=0.95, MeOH).

Workup

  1. stirringThe whole was stirred at room temperature for 30 minutes
  2. extractionextracted with ethyl acetate
  3. washThe ethyl acetate layer was washed with water
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated
  6. customThe residue was crystallized from hexane

Sources & evidence

ORD record
ord-9eabbaab1b31466eb8745f192c8983cf
Source dataset
uspto-grants-1988_09
Patent number
US04771050

Reaction notes

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