Iodine → 4-((1R,2S)-2-(tert-Butyldimethylsilyloxy)-1-(5-(4-(methylsulfonyl)phenyl)-1,3,4-oxadiazol-2-yl)propylamino)-2-chlorobenzonitrile

Participants

Reaction Steps

Polymer supported triphenylphosphine (2.08 g, 6.24 mmol) was diluted in 200 ml of DCM followed by addition of I2 (1.58 g, 6.24 mmol) and TEA (2.31 mL, 16.64 mmol) at 0° C. N′-((2R,3S)-3-(tert-butyldimethylsilyloxy)-2-(3-chloro-4-cyanophenylamino)butanoyl)-4-(methylsulfonyl)benzohydrazide (2.35 g, 4.16 mmol) in 200 mL DCM was added to the pre-cooled solution mixture of PPh3/I2/TEA system and stirred. The temperature was allowed to warm to room temperature and stirred for an additional 10 min. The reaction was quenched with 55 mL saturated sodium thiosulfate and the biphasic mixture was separated. The aqueous layer was extracted with EtOAc (3×70 mL) and the combined organic extracts were dried (Na2SO4), filtered and concentrated under reduced pressure. The resulting crude oil was purified by flash chromatography (SiO2) [EtOAc-hexanes (1:2), then (1:1) as eluent] to provide the title compound (2.16 g, 95%). The crude material was used directly in the next step.

Provenance & Evidence