Sodium Hydroxide → tert-butyl (1R,2R)-1-(5-bromo-2-fluoropyridin-3-yl)-2-(2,5-difluorophenyl)-2-hydroxyethylcarbamate

Participants

Reaction Conditions

Reaction Steps

To tert-butyl carbamate (0.462 g, 3.95 mmol) in propanol (6 mL) was added sodium hydroxide (0.155 g, 3.88 mmol) in water (12 mL) followed by tert-butyl hypochlorite (0.438 mL, 3.88 mmol). The solution was cooled to 0° C., and (DHQD)2PHAL (0.060 g, 0.076 mmol) was added in propanol (6 mL), followed by (E)-5-bromo-3-(2,5-difluorostyryl)-2-fluoropyridine (0.4 g, 1.273 mmol) as a solid. The remaining residue was dissolved in propanol (12 mL) and added to the reaction mixture to give a suspension. To this was added potassium osmate dihydrate (0.019 g, 0.051 mmol) as a solid in one portion. The reaction was allowed to gradually warm in the dewar overnight. The reaction was recooled to 0° C., and the reaction quenched by addition of sodium thiosulfate (0.5 g) in water (3 mL). The ice bath was removed, and the reaction stirred at room temperature for 30 min. The reaction was diluted with diethyl ether, washed with water (2×), then brine, dried over magnesium sulfate, and concentrated. Column chromatography (25% EtOAc/Hex) gave 0.445 g (78%) as a white foam solid. Mass spec.: 447.1 (MH)+.

Provenance & Evidence