Bromide ion → HCID 22118336, compound

HRID 1274884Notes

Reaction equation

HRID 1274884 reaction equation
Br[C:2]1[CH2:6][CH2:5][CH2:4][CH:3]=1.[Mg].[Br-].[CH3:9][C:10]1[O:15][CH2:14][N:13]([C:16]([CH3:20])([CH3:19])[CH:17]=[O:18])[C:12](=[O:21])[C:11]=1[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1.Cl>O1CCCC1.BrCCBr.C(OCC)(=O)C>[CH3:9][C:10]1[O:15][CH2:14][N:13]([C:16]([CH3:19])([CH3:20])[CH:17]([C:2]2[CH2:6][CH2:5][CH2:4][CH:3]=2)[OH:18])[C:12](=[O:21])[C:11]=1[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

9

Reactant 5

HCID 259Bromide ionHCID 313Hydrochloric AcidHCID 5462224MagnesiumHCID 109646601-bromocyclopenteneHCID 221182842-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde

Product 1

HCID 22118336HCID 22118336, compoundYield 98%

Reagents, catalysts & solvents 3

HCID 78391,2-DibromoethaneCatalystHCID 8028TetrahydrofuranSolvent3×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

A part of a solution of 1-bromocyclopent-1-ene (3.9 g) in tetrahydrofuran was added to a stirred mixture of magnesium turnings (0.68 g) and 1 drop of 1,2-dibromoethane in tetrahydrofuran at 20° C. under an inert atmosphere. The mixture was heated to reflux and the remaining bromide solution added dropwise over 15 minutes. The mixture was stirred for 0.5 hour, cooled to 0° C., and a solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde (4.0 g) in tetrahydrofuran added below 10° C. The mixture was stirred for 1 hour and ethyl acetate and hydrochloric acid (1N) added. The organic phase was washed (brine), dried (magnesium sulphate), evaporated and purified by silica gel column chromatography, eluting with n-hexane/ethyl acetate (2:1) to give 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(cyclopent-1-enyl)propan-1-ol (4.95 g), NMR: 1.45(s,3H), 1.60(s,3H), 1.90(s,3H), 1.80-1.92(2H), 2.15-2.53(4H), 4.37(d,1H), 5.04(d,1H), 5.20-5.30(2H), 5.63(s,1H), 7.22-7.41(5H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux
  3. stirringThe mixture was stirred for 1 hour
  4. washThe organic phase was washed (brine)
  5. dry with materialdried (magnesium sulphate)
  6. customevaporated
  7. custompurified by silica gel column chromatography
  8. washeluting with n-hexane/ethyl acetate (2:1)

Sources & evidence

ORD record
ord-9b663a9f26524d0b92bec381a6935579
Source dataset
uspto-grants-2000_12
Patent number
US06159902

Reaction notes

Loading…