Imidazole → 4-Bromo-N'-((2R,3S)-3-(tert-butyldimethylsilyloxy)-2-(3-chloro-4-cyano-2-methylphenylamino)butanoyl)benzohydrazide

Participants

Reaction Steps

To a solution of 4-bromo-N′-((2R,3S)-2-(3-chloro-4-cyano-2-methylphenylamino)-3-hydroxybutanoyl)benzohydrazide (4.0 g, 8.6 mmol) in DMF (60 mL) were added imidazole (2.3 g, 33.8 mmol) and TBSCl (2.6 g, 17.2 mmol) at 0° C. After addition, the mixture was allowed to warm to room temperature gradually and stirred overnight. The reaction was quenched by adding ice-water and extracted with EtOAc. The EtOAc extracts were washed with water, brine and dried over Na2SO4. Removal of the solvent gave a residue, which was purified by SiO2 column to give the title compound (4.68 g, 94%), which was used directly in the next step.

Provenance & Evidence