Sodium Hydroxide → HCID 59570886, compound

Participants

Reaction Steps

To a solution of 2-[3-cyclopropyl-4-(cyclopropylsulfonyl)phenyl]-3-[(2R,3R,7R)-2,3-diphenyl-1,4-dioxaspiro[4.4]non-7-yl]propionic acid (70.8 g) in THF (350 mL) were added triethylamine (21 mL) and 2,2-dimethylpropanoyl chloride (19 mL) at an internal temperature of 11° C. or lower under ice-cooling, followed by stirring at room temperature for 1 hour. In another vessel, to a solution of (4R)-4-benzyl-1,3-oxazolidin-2-one (26.3 g) in THF (200 mL) was added 2.64 M n-butyl lithium/hexane solution (54.8 mL) at an internal temperature of −50° C. or lower, followed by warming to room temperature, stirring for 1 hour, and then cooling to an internal temperature of −60° C. To this reaction mixture was added dropwise the acid anhydride/THF mixture, which had been prepared previously, at an internal temperature of −50° C. or lower, followed by stirring at room temperature for 4 hours. 1 M Sodium hydroxide (600 mL) was added thereto under ice-cooling and the organic solvent was evaporated under reduced pressure, followed by extraction with ethyl acetate/hexane (1/3, 200 mL×3). The organic layer was sequentially washed with a saturated aqueous ammonium chloride solution (200 mL) and saturated brine (200 mL), and dried over anhydrous sodium sulfate, and the solvent was then evaporated under reduced pressure to obtain (4R)-4-benzyl-3-{2-[3-cyclopropyl-4-(cyclopropylsulfonyl)phenyl]-3-[(2R,3R,7R)-2,3-diphenyl-1,4-dioxaspiro[4.4]non-7-yl]propanoyl}-1,3-oxazolidin-2-one (72 g) as a brown oil.

Provenance & Evidence