Imidazole → (E)-ethyl 7-(tert-butyldimethylsiloxy)-2-methyl-2-heptenate

HRID 658960Notes

Reaction equation

HRID 658960 reaction equation
C(Cl)Cl.[OH:4][CH2:5][CH2:6][CH2:7][CH2:8]/[CH:9]=[C:10](\[CH3:16])/[C:11]([O:13][CH2:14][CH3:15])=[O:12].N1C=CN=C1.[Si:22](Cl)([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23]>CN(C)C=O>[O:4]([CH2:5][CH2:6][CH2:7][CH2:8]/[CH:9]=[C:10](\[CH3:16])/[C:11]([O:13][CH2:14][CH3:15])=[O:12])[Si:22]([C:25]([CH3:28])([CH3:27])[CH3:26])([CH3:24])[CH3:23]

Participants

6

Reactant 4

HCID 795Imidazole2×HCID 6344DichloromethaneHCID 28928tert-Butyldimethylsilyl chlorideHCID 10559469(E)-ethyl 7-hydroxy-2-methyl-2-heptenate

Product 1

HCID 11055704(E)-ethyl 7-(tert-butyldimethylsiloxy)-2-methyl-2-heptenateYield 98.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a methylene chloride solution (300 ml) of Ester 3 (13.91 g; 0.0748 mol), 43 ml of DMF (dimethylformamide) and imidazole (7.6 g; 0.112 mol) are added and the whole is stirred until imidazole is fully dissolved. Tert-butyldimethylsilyl chloride (13.5 g; 0.0897 mol) is then added thereto and the whole is stirred for 20 min. After stirring, the resultant solution is quenched using a buffer solution (100 ml) and the organic compound is extracted three times with ethyl acetate, followed by the wash of the organic layer in a saturated saline solution and drying over anhydrous magnesium sulfate. After anhydrous magnesium sulfate is filtered and the solvent is distilled off under reduced pressure, the residue is separated and purified by column chromatography (developing solution, ethyl acetate:hexane=1:1) to produce Ester 4 (22.16 g; 0.0739 mol) of 99% in yield.

Workup

  1. dissolutionis fully dissolved
  2. stirringAfter stirring
  3. customthe resultant solution is quenched
  4. extractionthe organic compound is extracted three times with ethyl acetate
  5. washwash of the organic layer in a saturated saline solution
  6. dry with materialdrying over anhydrous magnesium sulfate
  7. filtrationAfter anhydrous magnesium sulfate is filtered
  8. distillationthe solvent is distilled off under reduced pressure
  9. customthe residue is separated
  10. custompurified by column chromatography (developing solution, ethyl acetate:hexane=1:1)

Sources & evidence

ORD record
ord-562ee5a0ecad40a38ec6091b3810ad52
Source dataset
uspto-grants-2011_12
Patent number
USRE043038E1

Reaction notes

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