Benzyl Bromide → 4-benzyl-6-bromo-spiro[3H-1,4-benzoxazine-2,1-cyclopropane]
Reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:12][C:9]3([CH2:11][CH2:10]3)[CH2:8][NH:7][C:6]=2[CH:13]=1.C(=O)([O-])[O-].[K+].[K+].[CH2:20](Br)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1>CN(C=O)C>[CH2:20]([N:7]1[C:6]2[CH:13]=[C:2]([Br:1])[CH:3]=[CH:4][C:5]=2[O:12][C:9]2([CH2:10][CH2:11]2)[CH2:8]1)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1Participants
5
Conditions
- Temperature
- 60 °C
Procedure
To a stirred solution of 6-bromospiro[3,4-dihydro-1,4-benzoxazine-2,1′-cyclopropane] (3.11 g, 12.9 mmol) in DMF (20 mL) was added potassium carbonate (3.6 g, 26.0 mmol) and benzyl bromide (1.61 mL, 13.6 mmol). The reaction mixture was heated at 60° C. for 6 h then cooled to room temperature and quenched by the addition of water. The reaction mixture was extracted with ethylacetate (2×50 mL) and the combined organic layers were washed with water (20 mL) and brine (20 mL), then dried over sodium sulfate, filtered and concentrated. The crude product was purified by silica gel column chromatography to furnish 4-benzyl-6-bromo-spiro[3H-1,4-benzoxazine-2,1-cyclopropane] (1.13 g).
Workup
- temperaturethen cooled to room temperature
- customquenched by the addition of water
- extractionThe reaction mixture was extracted with ethylacetate (2×50 mL)
- washthe combined organic layers were washed with water (20 mL) and brine (20 mL)
- dry with materialdried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated
- customThe crude product was purified by silica gel column chromatography
Sources & evidence
- ORD record
- ord-7d18a66a4dda4a13ab947ee2b3049d10
- Source dataset
- uspto-grants-2012_04
- Patent number
- US08163704B2
Reaction notes
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