Magnesium Bromide → HCID 10810945, compound

HRID 2258338Notes

Reaction equation

HRID 2258338 reaction equation
Br[C:2]1[CH:3]=[C:4]([CH:13]=[CH:14][CH:15]=1)[O:5][Si:6]([C:9]([CH3:12])([CH3:11])[CH3:10])([CH3:8])[CH3:7].[Br-].[Mg+2].[Br-].[Br:19][C:20]1[CH:21]=[C:22]([CH:25]=[O:26])[S:23][CH:24]=1>O1CCCC1.CCCCCC.ClCCl>[Br:19][C:20]1[CH:21]=[C:22]([CH:25]([OH:26])[C:2]2[CH:15]=[CH:14][CH:13]=[C:4]([O:5][Si:6]([C:9]([CH3:12])([CH3:11])[CH3:10])([CH3:8])[CH3:7])[CH:3]=2)[S:23][CH:24]=1

Participants

7

Reactant 3

HCID 82241Magnesium BromideHCID 877924-Bromothiophene-2-carbaldehydeHCID 11254705(3-Bromophenoxy)(tert-butyl)dimethylsilane

Product 1

HCID 10810945HCID 10810945, compoundYield 48.2%

Reagents, catalysts & solvents 3

HCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent3×HCID 8058HexaneSolvent2×

Conditions

Temperature
-78 °C

Procedure

3-Bromophenoxy-tert-butyldimethylsilane (30.2 g, 0.105 mol), prepared as in Example 1, was dissolved in 300 mL of dry tetrahydrofuran under nitrogen and cooled to -78° C. A solution of 1.6M n-butylithium in hexane (66 mL, 0.105 mol) was added dropwise at a rate to maintain a temperature below -65° C. The reaction was stirred for thirty minutes after the addition was complete and the cold solution was transferred to another vessel containing a room temperature solution of magnesium bromide (20.2 g, 0.11 mol) in 400 mL of dry tetrahydrofuran under nitrogen. The resulting solution was allowed to warm to 15° C. while stirring. After one hour a solution of 4-bromo-2-thiophenecarboxaldehyde (20.0 g, 0.105 mol) in 100 mL of dry tetrahydrofuran was added slowly at a rate to maintain a temperature below 25° C. The resulting solution was stirred for three hours at room temperature, then washed three times with aqueous ammonium chloride, dried over sodium sulfate and evaporated to give a yellow oil. Chromatography on silica gel with dichloromethane:hexane/50:50 gave 20.23 g (48.2%) of α-(4-bromo-2-thienyl)-3-((tert-butyldimethylsilyl)-oxy)benzyl alcohol as a viscous yellow oil.

Workup

  1. temperatureto maintain a temperature below -65° C
  2. additionafter the addition
  3. customthe cold solution was transferred to another vessel
  4. temperatureto warm to 15° C.
  5. stirringwhile stirring
  6. temperatureto maintain a temperature below 25° C
  7. stirringThe resulting solution was stirred for three hours at room temperature
  8. washwashed three times with aqueous ammonium chloride
  9. dry with materialdried over sodium sulfate
  10. customevaporated
  11. customto give a yellow oil

Sources & evidence

ORD record
ord-b9c2836060a441138abce8cbf3141a07
Source dataset
uspto-grants-1997_08
Patent number
US05658908

Reaction notes

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