Sodium Thiosulfate Pentahydrate → Tert-butyl 3-bromo-5-formylbenzoate

Participants

Reaction Steps

To a suspension of potassium bromide (249.3 g, 2.095 mol), 2,2,6,6-tetramethylpiperidine 1-oxyl (3.27 g, 20.93 mmol) in saturated aqueous sodium bicarbonate (960 mL) and water (240 mL) were added tert-butyl 3-bromo-5-(hydroxymethyl)benzoate (119.7 g, 417 mmol) and dichloromethane (1200 mL). The mixture was cooled to <5° C. and sodium hypochlorite (850 mL, 12.53 mol) was added dropwise in 4 portions until the reaction completed. A solution of sodium thiosulfate pentahydrate (72 g) in water (250 mL) was added and the reaction mixture was warmed to ambient temperature. The organic layer was separated and the aqueous layer was extracted with dichloromethane (2×). The combined organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated (119.0 g).

Provenance & Evidence