Lithium Hexamethyldisilazide → Methyl 2-(5-((tert-butyldimethylsilyloxy)methyl)thiophen-2-yl)-3-(1,3-dioxoisoindolin-2-yl)propanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of LiHMDS in THF cooled to −78° C. was added a cooled solution (approx −78° C.) of methyl 2-(5-((tert-butyldimethylsilyloxy)methyl)thiophen-2-yl)acetate (E232) in THF via syringe. The solution was stirred at −78° C. for 30 min. Bromo-methylphthalimide was added directly to the anion, and the solution was immediately removed from the −78° C. bath and placed in an ice bath and stirred for 2 h. The reaction was then poured into NH4Cl(sat) and extracted with EtOAc. The organics were dried (Na2SO4), filtered, and evaporated. Column chromatography (SiO2, 15-20% EtOAc/Hexanes) gave pure methyl 2-(5-((tert-butyldimethylsilyloxy)methyl)thiophen-2-yl)-3-(1,3-dioxoisoindolin-2-yl)propanoate (E233).

Provenance & Evidence