Reaktion #71047

Reaktionsgleichung

NH4Cl

N2

4-bromo-2-(tert-butyl-dimethyl-silanyloxymethyl)-thiazole

n-BuLi

N,N-dimethylacetamide

→

title compound

1-[2-(tert-Butyl-dimethyl-silanyloxymethyl)-thiazol-4-yl]-ethanone

Lösungsmittel

Et2O

—

hexanes

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   Sonstigethe layers separated
3. 3
   Extraktionthe aq. layer extracted with Et2O (3×30 mL)
4. 4
   Trocknenextracts were dried over Na2SO4
5. 5
   Filtrationfiltered
6. 6
   Sonstigethe solvent was removed under reduced pressure
7. 7
   SonstigePurification of the residue by FC (20:1->5:1 hept-EA)

Vorschrift

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), to a solution of 4-bromo-2-(tert-butyl-dimethyl-silanyloxymethyl)-thiazole (1.94 g, 6.29 mmol) in dry Et2O (50 mL) was added n-BuLi (2.76 mL of a 2.5M solution in hexanes, 6.92 mmol) at −78° C. The reaction mixture was then stirred for 30 min at −78° C. before N,N-dimethylacetamide (1.17 mL, 12.58 mmol) was added dropwise. The reaction mixture was allowed to warm up to rt over a period of 1 h and stirred at this temperature for 20 min. Sat. aq. NH4Cl (20 mL) was added, the layers separated and the aq. layer extracted with Et2O (3×30 mL). The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (20:1->5:1 hept-EA) gave the title compound as a yellow solid. TLC:rf (1:1 hept-EA)=0.51. LC-MS-conditions 02: tR=1.11 min; [M+H]+=272.39.

Quelle