1,2-Dibromoethane → 2-[4,5-Dimethoxy-2-(1-methyl-2-phenyl-ethyl)-phenyl]-4,4-dimethyl-4,5-dihydro-oxazole

HRID 1677233

Reaction equation

HRID 1677233 reaction equation
[Mg].BrCCBr.Br[CH:7]([CH3:15])[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.O1CCN=C1.[CH3:21][C:22]1([CH3:39])[CH2:26][O:25][C:24]([C:27]2[CH:32]=[C:31]([O:33][CH3:34])[C:30]([O:35][CH3:36])=[CH:29][C:28]=2OC)=[N:23]1>O1CCCC1.CCCCCC.C(OCC)(=O)C>[CH3:36][O:35][C:30]1[C:31]([O:33][CH3:34])=[CH:32][C:27]([C:24]2[O:25][CH2:26][C:22]([CH3:21])([CH3:39])[N:23]=2)=[C:28]([CH:7]([CH3:15])[CH2:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH:29]=1

Participants

7

Reactant 4

HCID 78391,2-DibromoethaneHCID 102754(2-Bromopropyl)benzeneHCID 5462224MagnesiumHCID 670534204,4-Dimethyl-2-(2,4,5-trimethoxy-phenyl)-4,5-dihydro-oxazole oxazoline

Product 1

HCID 595987102-[4,5-Dimethoxy-2-(1-methyl-2-phenyl-ethyl)-phenyl]-4,4-dimethyl-4,5-dihydro-oxazoleYield 60.9%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 21226206Ethyl acetate hexaneSolvent

Conditions

Temperature
40 °C

Procedure

To a rapidly stirring suspension of magnesium turnings (1.32 g, 54.5 mol) and in 35 mL tetrahydrofuran (THF) was added 1,2-dibromoethane (0.10 mL) in one portion. 2-bromo-1-phenylpropane (10.86 g, 54.5 mmol) was added at a rate that maintained the internal temperature at 40° C. After 2.5 hours the cloudy suspension was transferred via canula to a solution of 4,4-dimethyl-2-(2,4,5-trimethoxy-phenyl)-4,5-dihydro-oxazole oxazoline (10.013 g, 36.4 mmol) in 50 mL THF. After 18 hours the solution cooled to 0° C. and quenched by the slow addition of 10% NH4Cl. 500 mL H2O was added and the mixture was extracted with ethyl acetate, washed with H2O, and washed with brine. The combined organics were dried over Na2SO4, filtered and concentrated in vacuo to give a crude solid. Purifications via flash chromatography (4:1 hexane/ethyl acetate) afforded 2-[4,5-dimethoxy-2-(1-methyl-2-phenyl-ethyl)-phenyl]-4,4-dimethyl-4,5-dihydro-oxazole as a clear viscous oil (7.833 g, 41%).

Workup

  1. temperatureAfter 18 hours the solution cooled to 0° C.
  2. customquenched by the slow addition of 10% NH4Cl
  3. addition500 mL H2O was added
  4. extractionthe mixture was extracted with ethyl acetate
  5. washwashed with H2O
  6. washwashed with brine
  7. dry with materialThe combined organics were dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customto give a crude solid

Sources & evidence

ORD record
ord-1e3e5787331c46459022167b57af1e58
Source dataset
uspto-grants-2011_08
Patent number
US08008313B2

Linked notes

Loading…