N#N.Br[C:4]1[S:5][C:6]([C:9]([CH3:17])([CH3:16])[O:10][SiH2:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[CH:7][N:8]=1.[Li]CCCC.CN(C)[C:25](=[O:27])[CH3:26].[NH4+].[Cl-]>CCOCC>[C:12]([SiH2:11][O:10][C:9]([CH3:17])([CH3:16])[C:6]1[S:5][C:4]([C:25](=[O:27])[CH3:26])=[N:8][CH:7]=1)([CH3:15])([CH3:14])[CH3:13]In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 2-bromo-5-(tert-butyl-dimethyl-silanyloxymethyl)-thiazole (3.00 g, 9.73 mmol) in dry Et2O (20 mL) was added to a n-BuLi (4.30 mL of a 2.5M solution in hexanes, 10.70 mmol) solution in Et2O (50 mL) at −78° C. The reaction mixture was then stirred for 40 min at −78° C. before N,N-dimethylacetamide (1.81 mL, 19.46 mmol) was added dropwise. The reaction mixture was allowed to warm up to −50° C. 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 (3×20 mL). The combined org. extracts were dried over Na2SO4, filtered, and the solvent was removed under reduced pressure to give the title compound as a yellow oil. TLC:rf (1:2 hept-EA)=0.80. LC-MS-conditions 01: tR=1.09 min, [M+1-1]+=271.98.
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